S-3/A

As filed with the Securities and Exchange Commission on February 3, 2010

Registration No. 333-163972

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

Amendment No.2 to

FORM S-3

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

AMERICAN DG ENERGY INC.

(Exact name of registrant as specified in its charter)

Delaware	1711	04-3569304
(State or other jurisdiction of	(Primary Standard Industrial	(I.R.S. Employer
incorporation or organization)	Classification Code Number)	Identification No.)

American DG Energy Inc.

45 First Avenue

Waltham, MA 02451

781-622-1120

(Address, including zip code, and telephone number,

including area code, of registrant’s principal executive offices)

	Copy to:
John N. Hatsopoulos	Edwin L. Miller Jr.
Chief Executive Officer	Sullivan & Worcester LLP
American DG Energy Inc.	One Post Office Square
45 First Avenue	Boston, MA 02109
Waltham, MA 02451	Tel: (617) 338-2800/Fax: (617) 338-2880
(781) 622-1120/Fax: (781) 622-1027
(Name, address, including zip code, and telephone number, including area code, of agent for service)

Approximate date of commencement of proposed sale to the public:

From time to time after this registration statement becomes effective

If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, check the following box.  ¨

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box.  R

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  o

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ¨

If this form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. (Check one):

Large accelerated filer: ¨ Accelerated filer: ¨ Non-accelerated filer: ¨ Smaller reporting company: R

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

PROSPECTUS (Subject to Completion)

Dated February 3, 2010

PROSPECTUS

8,931,836 Shares of Common Stock

We are registering for resale pursuant to this prospectus shares of our outstanding common stock, shares issuable upon conversion of outstanding convertible debentures and shares issuable upon exercise of outstanding warrants, other than shares that may be sold without restriction pursuant to Rule 144.

Included in the aggregate number of shares are: 3,548,405 outstanding shares of common stock; 5,321,431 shares issuable upon conversion of outstanding convertible debentures, and 62,000 shares issuable upon exercise of warrants.

Our common stock is traded on the NYSE Amex under the symbol “ADGE”. The last reported sale price of our common stock on February 2, 2010, was $2.95 per share.

The selling stockholders may sell all or a portion of their shares on the NYSE Amex at prices prevailing at the time of sale, or related to the market price at the time of sale, or they may otherwise sell their shares at negotiated prices. Certain of the selling stockholders are persons employed by or otherwise associated with a broker-dealer, and therefore are underwriters under the Securities Act of 1933 with respect to the shares they sell pursuant to this prospectus.

We will not receive any of the proceeds from the offer and sale of the shares. If the warrants related to the shares of common stock offered for sale pursuant to this prospectus are exercised in full, we will receive aggregate proceeds from such exercises of $150,000. We will pay the expenses of this offering.

Our business and an investment in our common stock involve significant risks. You should refer to the factors described in the section called “Risk Factors” contained in our Annual Report on Form 10-K, page 10, for our 2008 fiscal year that has been incorporated by reference in this prospectus. See page 2 for the reference.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is __________.

TABLE OF CONTENTS

About this Prospectus	2
Special Note Regarding Forward-Looking Statements	2
About the Company	3
Dividend Policy	3
Use of Proceeds	3
Determination of Offering Price and Market Data	3
Selling Stockholders	4
Plan of Distribution	9
Experts	9
Incorporation by Reference	9
Where You Can Find More Information	11

ABOUT THIS PROSPECTUS

In this prospectus, references to the “company,” “we,” “us,” “our,” and “registrant” refer to American DG Energy Inc.

You should rely only on the information contained in this prospectus. We have not, and the selling stockholders have not, authorized anyone to provide you with information that is different. The selling stockholders are offering to sell and seeking offers to buy shares of our common stock only in jurisdictions where offers and sales are permitted. You should assume that the information appearing in this prospectus as well as the information we filed previously with the Securities and Exchange Commission, or SEC, and incorporated herein by reference is accurate only as of the date of the document containing the information.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference contain forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical fact, included in this prospectus regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects and plans and objectives of management are forward-looking statements. The words “anticipates,” “believes,” “estimates,” “expects,” “intends,” “may,” “plans,” “projects,” “will,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

We have based these forward-looking statements on our current expectations and projections about future events. Although we believe that the expectations underlying our forward-looking statements are reasonable, these expectations may prove to be incorrect, and all of these statements are subject to risks and uncertainties. Therefore, you should not place undue reliance on our forward-looking statements. We have included important risks and uncertainties in the cautionary statements included in this prospectus, particularly the section called “Risk Factors” incorporated by reference herein. We believe these risks and uncertainties could cause actual results or events to differ materially from the forward-looking statements that we make. Should one or more of these risks and uncertainties materialize, or should underlying assumptions, projections or expectations prove incorrect, actual results, performance or financial condition may vary materially and adversely from those anticipated, estimated or expected. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make. We do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

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ABOUT THE COMPANY

We distribute and operate on-site cogeneration systems that produce both electricity and heat. Our business is to own the equipment that we install at customers’ facilities and to sell the energy produced by these systems to the customers on a long-term contractual basis. We call this business the American DG Energy “On-Site Utility”.

We offer a range of cogeneration systems that are highly reliable and energy efficient. Our cogeneration systems produce electricity from an internal combustion engine driving a generator, while the heat from the engine and exhaust is recovered and typically used to produce heat and hot water for on-site processes. We also distribute and operate water chiller systems that operate in a similar manner, except that the engine’s power drives a large air-conditioning compressor while recovering heat for hot water. Cogeneration systems reduce the amount of electricity that the customer must purchase from the local utility and produce valuable heat and hot water for the site to use as required.

The company was incorporated as a Delaware corporation on July 24, 2001. American DG Energy operated as a subsidiary of American Distributed Generation Inc. since 2003, along with Tecogen Inc. In December 2005, American DG Energy merged with American Distributed Generation Inc., and the company then changed its name to American DG Energy Inc. Our principal executive offices are located at 45 First Avenue, Waltham, Massachusetts 02451.

DIVIDEND POLICY

We have never declared or paid any cash dividends on shares of our common stock. We currently intend to retain earnings, if any, to fund the development and growth of our business and do not anticipate paying cash dividends in the foreseeable future. Our payment of any future dividends will be at the discretion of our board of directors after taking into account various factors, including our financial condition, operating results, cash needs and growth plans.

USE OF PROCEEDS

We will not receive any of the proceeds from the offer and sale of the shares. If the warrants related to the shares of common stock offered for sale pursuant to this prospectus are exercised in full, we will receive aggregate proceeds from such exercises of $150,000. The funds we will receive from the proceeds of exercises of options related to shares of common stock or rights to purchase shares of common stock pursuant to our private placement will be used for installation of additional energy systems and for general corporate purposes.

DETERMINATION OF OFFERING PRICE AND MARKET DATA

Offering Price

The selling stockholders may sell all or a portion of their shares in the NYSE Amex market at prices prevailing at the time of sale, or related to the market price at the time of sale, or they may otherwise sell their shares at negotiated prices. We cannot determine what the actual offering price will be at the time of sale.

Market

Our common stock started trading on November 8, 2007, on the OTC Bulletin Board, or OTCBB, under the symbol “ADGE”. OTCBB market quotations reflect inter-dealer prices, without retail mark-up, mark-down or commissions and may not necessarily represent actual transactions.

During the period from November 8, 2007 to December 31, 2007, the high price was $1.25 and the low price was $0.83 as reported by the OTCBB. The following table sets forth the high and low per share sales prices for our common stock for each of the quarters in the period beginning January 1, 2008, through December 31, 2009, as reported by the OTCBB. On October 19, 2009, the company’s common stock began trading on the NYSE Amex market.

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Quarter Ended	High		Low
March 31, 2008	$	1.09	$	0.73
June 30, 2008	$	1.92	$	1.01
September 30, 2008	$	2.05	$	1.35
December 31, 2008	$	2.31	$	1.65
March 31, 2009	$	2.20	$	1.50
June 30, 2009	$	3.25	$	2.45
September 30, 2009	$	3.08	$	2.70
December 31, 2009	$	3.55	$	2.52

The closing price of our common stock as reported on the NYSE Amex on February 2, 2010, was $2.95 per share.

Holders

As of February 2, 2010, there were approximately 610 beneficial holders of our common stock.

SELLING STOCKHOLDERS

We are registering for resale pursuant to this prospectus shares of our outstanding common stock, shares issuable upon conversion of outstanding convertible debentures and shares issuable upon conversion or exercise of our outstanding warrants. Included in the aggregate number of shares are: 3,548,405 outstanding shares of common stock; 5,321,431 shares issuable upon conversion of outstanding convertible debentures, and 62,000 shares issuable upon exercise of warrants.

All of the shares of our common stock offered under this prospectus are being sold by the holders thereof and not by the company. All costs, expenses and fees in connection with the registration of the selling stockholders’ shares will be borne by us. All brokerage commissions, if any, attributable to the sale of shares by selling stockholders will be borne by such holders.

Each selling stockholder may sell all, none or a portion of the shares offered. We cannot estimate the number of shares of common stock that the selling stockholders will sell pursuant to this prospectus.

Beneficial ownership is determined in accordance with the rules of the SEC. These rules generally attribute beneficial ownership of securities to persons who possess sole or shared voting power or investment power with respect to those securities. Except as otherwise indicated, all persons listed below have sole voting and investment power with respect to the shares beneficially owned by them, subject to applicable community property laws. The information is not necessarily indicative of beneficial ownership for any other purpose. With respect to selling stockholders that are entities, the individuals who have voting or investment power over the shares, as indicated, disclaim beneficial ownership of the securities except for their pecuniary interest therein.

None of the selling stockholders is in the business of buying and selling securities. Certain selling stockholders are, however, affiliated with broker-dealers. Mr. Charles T. Maxwell is affiliated with Weeden & Co. LP., Mr. Adam Schachter and Mrs. Nancy Schachter are affiliated with Wells Fargo Advisors, Mr. Michael Zuk is affiliated with Oppenheimer & Co., Mr. Edward Crouch is affiliated with Herbert J. Sims & Co., and Mr. Gary David Cunningham and Mr. Mehdi Sunderji are affiliated with Execution LLC. The aforementioned investors each purchased the securities in the ordinary course of their personal investment activities (or for their investment accounts) and at the time of the purchases none of them had any agreements or understandings directly or indirectly with any person to distribute the securities. No other selling stockholders are themselves, or are affiliated with, a broker-dealer. Other than Charles T. Maxwell, a director of the company, none of the selling stockholders has held any position or office, or had any other material relationship with the company within the past three years. If any shares of our common stock are sold by the aforementioned investors pursuant to this prospectus, they will be underwriters with respect thereto under the Securities Act.

Percentage ownership calculations are based on shares beneficially owned and shares outstanding as of February 2, 2010. The following table sets forth certain beneficial ownership information with regard to the selling stockholders both before the offering and after the offering as if each shareholder had separately sold all shares registered.

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	Shares Beneficially Owned							Shares Beneficially Owned
	Prior to Offering					Shares Being		After Offering
Selling stockholder	Number		Percentage			Offered (1)		Number		Percentage
In Holdings Corp. (2)		4,961,905		11.86	%		4,961,905		-		*
Nettlestone Enterprises Limited (3)		3,148,140		8.36	%		676,190		2,471,950		6.56	%
RBC cees Nominees Ltd. B2599/B3957 (4)		357,143		*			357,143		-		*
Charles T. Maxwell (5)		442,858		1.17	%		342,858		100,000		*
Frederick Frank (6)		297,619		*			297,619		-		*
RBC cees Nominees Ltd. B2602/B3923 (7)		250,000		*			250,000		-		*
Global Pensions (8)		250,000		*			250,000		-		*
Berger van Berchem & Co. Ltd. (9)		591,700		1.57	%		250,000		341,700		*
William O. & Sandra M. Flannery, JTWROS (10)		238,095		*			238,095		-		*
Jeremy Benjamin		119,048		*			119,048		-		*
Alexandra O. Bjorklund (11)		119,048		*			119,048		-		*
Ernest Aloi & Catherine Aloi (12)		119,048		*			119,048		-		*
Despina B. Theocharakis		100,000		*			100,000		-		*
F.V.A Mellish		100,000		*			100,000		-		*
Bruno Meier		100,000		*			100,000		-		*
Gundyco In Trust for Hans Schopper (13)		100,000		*			100,000		-		*
Adam Schachter (14)		72,024		*			72,024		-		*
Richard Aghababian (15)		59,524		*			59,524		-		*
Bruce Wainer (16)		59,524		*			59,524		-		*
Daniel Barnett (17)		50,000		*			50,000		-		*
Kenneth G. Eisner		50,000		*			50,000		-		*
Edward Miller (18)		65,000		*			40,000		25,000		*
Michael Zuk (19)		37,762		*			37,762		-		*
Edward Crouch (20)		29,762		*			29,762		-		*
Integrated Risk Facilities Holdings, Inc. (21)		23,810		*			23,810		-		*
David J. Talbot		20,000		*			20,000		-		*
John E. Shore Generation Skipping Trust (22)		20,000		*			20,000		-		*
Gary David Cunningham (23)		14,286		*			14,286		-		*
First Clearing LLC FBO Nancy Schachter (24)		12,500		*			12,500		-		*
Hayden IR (25)		12,000		*			12,000		-		*
Jo Ellen Spitz		12,000		*			12,000		-		*
Tina Argyropoulos		10,000		*			10,000		-		*
Edward J. Barber		10,000		*			10,000		-		*
Mehdi Sunderji (26)		7,500		*			7,500		-		*
Anthony Jack Smouha		5,000		*			5,000		-		*
Mark Gerstenfeld		4,000		*			4,000		-		*
Santuccio Ricciardi		1,190		*			1,190		-		*
Total		11,870,486					8,931,836		2,938,650

________________

* Represents beneficial ownership of less than 1% of our outstanding common stock.

1. Shares beneficially owned by our security holders and offered hereby consist of: 3,548,405 outstanding shares of common stock; 5,321,431 shares issuable upon conversion of outstanding convertible debentures, and 62,000 shares issuable upon exercise of warrants.

2. Includes: (a) 100,000 shares of common stock, par value $0.001 per share purchased on December 3, 2003; (b) 100,000 shares of common stock, par value $0.001 per share purchased on November 15, 2004; (c) 595,238 shares of common stock, par value $0.001 per share issued on April 6, 2009, upon conversion of $500,000 principal amount of the 8% convertible debentures; and (d) 4,166,667 shares of common stock that In Holdings Corp. has the right to acquire pursuant to currently convertible 8% senior debentures. Mr. Konstantinos Samaras exercises sole voting and/or dispositive power with respect to the shares of common stock that In Holdings Corp. holds or has the right to acquire pursuant to currently convertible 8% senior debentures. In Holdings Corp’s address is: Calle 50 No. 2, Edif Universal Planta Baja, Apartado 0816-02580, Republic of Panama.

3. Includes 3,148,140 shares of common stock, par value $0.001 per share held by Nettlestone Enterprises Limited. The address of Nettlestone Enterprises Limited is P.O. Box 665 Roseneath, The Grange, St. Peter Port, Guernsey GY1-3SJ, Channel Islands. Messrs. M.T.R Betley, M.S Heyworth and J.R Plimley are the Directors of the company and may be deemed to exercise voting and/or dispositive power with respect to these shares.

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4. Includes 357,143 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held by RBC cees Nominees Ltd. B2599/B3957. The address of RBC cees Nominees Ltd. is 19-21 Broad Street, St. Hellier, Jersey JE1 3PB, Channel Islands. Messrs. Jamie Dean and S.E McArthur-Wareing are the authorized signatories of the company and may be deemed to exercise voting and/or dispositive power with respect to these shares.

5. Includes: (a) 100,000 shares of common stock, par value $0.001 per share purchased on March 1, 2004; (b) 100,000 shares of restricted common stock, granted to Charles T. Maxwell on February 20, 2007 by permitting him to purchase an aggregate of 100,000 shares of common stock at a price of $0.001 per share; (c) 23,810 shares of common stock par value $0.001 per share purchased on April 23, 2009; (b) options to purchase 100,000 shares of common stock, exercisable within 60 days of February 2, 2010; and (c) 119,048 shares of common stock pursuant to currently convertible 8% senior debentures. Mr. Maxwell is affiliated with Weeden & Co. LP. The seller purchased the securities to be resold in the ordinary course of business and at the time of the purchase, the seller had no agreements or understandings directly or indirectly, with any person to distribute the securities.

6. Includes 297,619 shares of common stock that Mr. Fred Frank has the right to acquire pursuant to currently convertible 8% senior debentures.

7. Includes 250,000 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held by RBC cees Nominees Ltd. B2602/B3923. The address of RBC cees Nominees Ltd. is 19-21 Broad Street, St. Hellier, Jersey JE1 3PB, Channel Islands. Messrs. Jamie Dean and S.E McArthur-Wareing are the authorized signatories of the company and may be deemed to exercise voting and/or dispositive power with respect to these shares.

8. Includes 250,000 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held by Global Pensions. The address of Global Pensions c/o London Capital Asset Management is 4 Triton Square, Regent’s Place, London NW1 3HG, United Kingdom for the benefit of Mr. Costas Kaplanis. The Directors of Global Pensions are the London and Capital Satellite Board and may be deemed to exercise voting and/or dispositive power with respect to these shares.

9. Includes 591,700 shares of common stock, par value $0.001 per share held by Berger van Berchem & Co. Ltd. The address of Berger van Berchem & Co. Ltd is 26 Rue de la Corraterie, 1204 Geneva, Switzerland. Messrs. Jean-Michel Berger and Nicolas Maitre are the Directors of the company and may be deemed to exercise voting and/or dispositive power with respect to these shares.

10. Includes 238,095 shares of common stock that Mr. William O. & Sandra M. Flannery, JTWROS have the right to acquire pursuant to currently convertible 8% senior debentures.

11. Includes 119,048 shares of common stock that Mrs. Alexandra O. Bjorklund has the right to acquire pursuant to currently convertible 8% senior debentures.

12. Includes 119,048 shares of common stock that Mr. Ernest Aloi & Catherine Aloi have the right to acquire pursuant to currently convertible 8% senior debentures.

13. Includes 100,000 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held by Gundyco In Trust for Hans Schopper AC# 500-01915-27. The address of Gundyco c/o CIBC Wood Gundy is 1, Place Ville Marie, Suite 4125, Montreal QC, H3B 3P9, Canada, for the benefit of Mr. Schopper, for which Mr. Schopper is the sole trustee.

14. Includes: (a) 12,500 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held by Mr. Adam Schachter; and (b) 59,524 shares of common stock that Mr. Adam Schachter & Nicole Schachter have the right to acquire pursuant to currently convertible 8% senior debentures. Mr. Adam Schachter is affiliated with Wells Fargo Advisors. The seller purchased the securities to be resold in the ordinary course of business and at the time of the purchase, the seller had no agreements or understandings directly or indirectly, with any person to distribute the securities.

15. Includes 59,524 shares of common stock that Mr. Richard Aghababian has the right to acquire pursuant to currently convertible 8% senior debentures.

16. Includes 59,524 shares of common stock that Mr. Bruce Wainer has the right to acquire pursuant to currently convertible 8% senior debentures.

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17. Includes a warrant to purchase 50,000 shares of common stock issued on February 24, 2009, to Daniel Barnett, exercisable within 60 days of February 2, 2010.

18. Includes: (a) 40,000 shares of restricted common stock, granted to Edward Miller, an employee, by permitting him to purchase an aggregate of 40,000 shares of common stock at a price of $0.001 per share; and (b) options to purchase 25,000 shares of common stock, exercisable within 60 days of February 2, 2010.

19. Includes: (a) 8,000 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held by Mr. Michael Zuk; and (b) 29,762 shares of common stock that Mr. Michael Zuk & Gayle Line Zuk have the right to acquire pursuant to currently convertible 8% senior debentures. Mr. Michael Zuk is affiliated with Oppenheimer & Co. The seller purchased the securities to be resold in the ordinary course of business and at the time of the purchase, the seller had no agreements or understandings directly or indirectly, with any person to distribute the securities.

20. Includes 29,762 shares of common stock that Mr. Edward Crouch has the right to acquire pursuant to currently convertible 8% senior debentures. Mr. Crouch is affiliated with Herbert J. Sims & Co. The seller purchased the securities to be resold in the ordinary course of business and at the time of the purchase, the seller had no agreements or understandings directly or indirectly, with any person to distribute the securities.

21. Includes 23,810 shares of common stock that Integrated Risk Facilities Holdings, Inc. has the right to acquire pursuant to currently convertible 8% senior debentures. The address of Integrated Risk Facilities Holdings, Inc. is40 Fulton Street, New York, NY 10030 and Mr. Stuart Farber may be deemed to exercise voting and/or dispositive power with respect to these shares.

22. Includes 20,000 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held in the John E. Shore Generation Skipping Trust for the benefit of Mr. Shore, for which Mr. Shore is the sole trustee.

23. Includes 14,286 shares of common stock, par value $0.001 per share held by Mr. Gary David Cunningham who is affiliated with Execution LLC. The seller purchased the securities to be resold in the ordinary course of business and at the time of the purchase, the seller had no agreements or understandings directly or indirectly, with any person to distribute the securities.

24. Includes 12,500 shares of common stock, par value $0.001 per share purchased on July 24, 2009, held in a retirement account by First Clearing LLC FBO Nancy Schachter for the benefit of Mrs. Schachter for which Mrs. Schachter is the sole trustee. Mrs. Schachter is affiliated with Wells Fargo Advisors. The seller purchased the securities to be resold in the ordinary course of business and at the time of the purchase, the seller had no agreements or understandings directly or indirectly, with any person to distribute the securities.

25. Includes 12,000 warrants issued to Hayden IR on October 1, 2009, based on a vesting schedule, in connection with an investor relations agreement at an exercise price of $2.98. Of those warrants, 8,000 are exercisable within 60 days of February 2, 2010. The warrants carry a cashless exercise provision. Messrs. Peter Seltzberg and Jeff Stanlis are the Directors of the company and may be deemed to exercise voting and/or dispositive power with respect to these shares.

26. Includes 7,500 shares of common stock, par value $0.001 per share held by Mr. Mehdi Sunderji who is affiliated with Execution LLC. The seller purchased the securities to be resold in the ordinary course of business and at the time of the purchase, the seller had no agreements or understandings directly or indirectly, with any person to distribute the securities.

There are no family relationships among members of our Board or our executive officers, other than Dr. George N. Hatsopoulos and Mr. John N. Hatsopoulos who are brothers. Other than Charles T. Maxwell, a director of the company, none of the selling stockholders has held any position or office, or had any other material relationship with the company within the past three years.

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ACQUISITION TRANSACTIONS

A description of the transactions pursuant to which the shares registered hereby were acquired by the selling shareholders is as follows.

Between December 2003 and December 2005, the company raised in private placements $2,236,500 by selling to certain accredited investors 3,195,000 shares of common stock at a price of $0.70 per share. Included in those shares are 200,000 shares to In Holdings Corp., and 100,000 to Charles T. Maxwell. The form of the subscription agreement pursuant to which the shares were sold is filed herewith as Exhibit 10.12.

On February 20, 2007 the company made a restricted stock grant to Charles T. Maxwell, by permitting him to purchase an aggregate of 100,000 shares of common stock at a price of $0.001 per share. The grant vests 25% on January 2, 2008 and then 25% of the shares vest on each subsequent anniversary thereafter. The restricted stock grant was issued pursuant to the company’s 2005 Stock Incentive Plan. See Exhibit 10.13 for the form of the plan pursuant to which the restricted shares were granted.

In April and June 2006, the company sold an aggregate of $6,075,000 principal amount of its 8% convertible debentures to an aggregate of 15 persons. The fair market value of the common stock on the date of each closing of the convertible debentures was $0.70 and the conversion price into shares of common stock was $0.84. Total proceeds were approximately $5,425,000. One of the selling shareholders that participated in this transaction was In Holdings Corp. by purchasing a principal amount of $4,000,000, representing 4,761,905 shares of common stock issuable upon conversion of outstanding convertible debentures. See Exhibit 10.14 for the form of the subscription agreement pursuant to which the convertible debentures were issued. On April 6, 2009, In Holdings Corp. converted $500,000 of principal amount into 595,238 shares of the company’s common stock at a conversion price of $0.84.

In February 2007, the company raised in a private placement $1,505,000 by selling to Nettlestone Enterprises Limited, a selling shareholder, 2,150,000 shares of common stock at a price of $0.70 per share. The form of the subscription agreement pursuant to which the shares were sold is filed herewith as Exhibit 10.15.

On February 24, 2009, the company sold to Daniel Barnett, one of the selling shareholders, a warrant to purchase shares of common stock for a purchase price of $10,500. The warrant, which expires on February 24, 2012, gives the investor the right but not the obligation to purchase 50,000 shares of the company’s common stock at an exercise price per share of $3.00.  See Exhibit 10.16 for the form of the subscription agreement pursuant to which the warrants were sold.

On April 23, 2009, the company raised $2,260,000 in a private placement of 1,076,190 shares of common stock at a price of $2.10 per share. Included in those shares are 476,190 shares to Nettlestone Enterprises Limited, 23,810 shares to Charles T. Maxwell and 100,000 shares to Despina B. Theocharakis. All investors that participated in the offering are selling shareholders. See Exhibit 10.17 for the form of the subscription agreement pursuant to which the shares were sold.

On July 24, 2009, the company raised $3,492,650 in a private placement of 1,663,167 shares of common stock at a price of $2.10 per share. The company also granted the investors the right to purchase additional shares of common stock at a purchase price of $3.10 per share by December 18, 2009. Included in those shares are 200,000 shares to Nettlestone Enterprises Limited, 607,143 shares to RBC cees Nominees Ltd., 250,000 shares to Global Pensions, 119,048 shares to Jeremy Benjamin, 100,000 shares to F.V.A Mellish, 100,000 shares to Bruno Meier, 100,000 shares to Gundyco In Trust for Hans Schopper, 50,000 shares to Kenneth G. Eisner, 20,000 shares to David J. Talbot, 20,000 shares to John E. Shore Generation Skipping Trust, 14,286 shares to Gary David Cunningham, 12,500 shares to Adam C. Schachter, 12,500 shares to First Clearing LLC FBO Nancy Schachter, 12,000 shares to Jo Ellen Spitz, 10,000 shares to Tina Argyropoulos, 10,000 shares to Edward J. Barber, 8,000 shares to Michael Zuk, 7,500 shares to Mehdi Sunderji, 5,000 shares to Anthony Jack Smouha, 4,000 shares to Mark Gerstenfeld and 1,190 shares to Santuccio Ricciardi. All investors that participated in the offering are selling shareholders. See Exhibit 10.18 for the form of the subscription agreement pursuant to which the shares were sold.

On October 14, 2009, the company raised $525,000 in a private placement of 250,000 shares of common stock at a price of $2.10 per share. The company also granted the investor the right to purchase additional shares of common stock at a purchase price of $3.10 per share by December 18, 2009. Included in those shares are 250,000 shares to Berger van Berchem & Co. Ltd. The investor that participated in the offering is a selling shareholder. See Exhibit 10.19 for the form of the subscription agreement pursuant to which the shares were sold.

The subscription agreements pursuant to which the foregoing securities were purchased have been filed as exhibits to the Registration Statement, of which this prospectus forms a part.

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PLAN OF DISTRIBUTION

The selling stockholders and any of their pledgees, assignees and successors-in-interest may, from time to time, sell any or all of their shares of common stock covered by this prospectus at prevailing market prices on the NYSE Amex or at privately negotiated prices. We will pay the expenses incurred to register the shares being offered by the selling stockholders for resale, but the selling stockholders will pay any underwriting discounts and brokerage commissions associated with these sales. Any commission or discount will be negotiated immediately prior to the sale with the broker-dealer or agent. The selling stockholders may use any one or more of the following methods when selling shares:

· ordinary brokerage transactions and transactions in which the broker-dealer solicits purchasers;

· block trades in which the broker-dealer will attempt to sell the shares as agent but may position and resell a portion of the block as principal to facilitate the transaction;

· purchases by a broker-dealer as principal and resale by the broker-dealer for its account;

· privately negotiated transactions; and

· a combination of any such methods of sale.

In addition, any shares that qualify for sale under Rule 144 may be sold under Rule 144 rather than through this prospectus. Shares that qualify for unrestricted sale under Rule 144 may not be sold pursuant to this prospectus.

In offering the shares covered by this prospectus, selling stockholders who are employed by or otherwise associated with a broker-dealer will be underwriters under the Securities Act of 1933 with respect to the shares they sell pursuant to this prospectus. In addition, any broker-dealers who execute sales for such selling stockholders may be deemed to be an underwriter under the Securities Act in connection with such sales and any profits realized and the compensation of any such broker-dealer may be deemed to be underwriting discounts and commissions.

Transfer Agent

Our transfer agent is Continental Stock Transfer & Trust Company, 17 Battery Place, New York, NY 10004-1123; telephone: 212-509-4000.

EXPERTS

The financial statements of American DG Energy Inc. as of December 31, 2008 and 2007, and for each of the two years in the period ended December 31, 2008, included in our Annual Report on Form 10-K for the year ended December 31, 2008 incorporated by reference in this registration statement have been so incorporated in reliance on the report of Caturano and Company, P.C. (formerly known as Vitale, Caturano & Company, P.C.), independent registered public accountants, given on the authority of said firm as experts in auditing and accounting.

INCORPORATION OF DOCUMENTS BY REFERENCE

The SEC requires us to “incorporate by reference” into this prospectus information that we file with the SEC in other documents. This means that we can disclose important information to you by referring you to other documents that contain that information. The information we incorporate by reference is considered to be part of this prospectus. Information contained in this prospectus and information that we file with the SEC in the future and that we incorporate by reference in this prospectus automatically updates and supersedes previously filed information. We incorporate by reference the documents listed below and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus and prior to the sale of all the shares covered by this prospectus.

· The company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2008, filed with the Commission on March 20, 2009 (File No. 000-52294).

· The company’s Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2009, filed with the Commission on May 14, 2009 (File No. 000-52294).

· The company’s Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 2009, filed with the Commission on August 14, 2009 (File No. 000-52294).

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· The Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2009, filed with the Commission on November 12, 2009 (File No. 001-34493).

· The company’s current report on Form 8-K filed with the Commission on February 26, 2009 (File No. 000-52294).

· The company’s current report on Form 8-K filed with the Commission on March 4, 2009 (File No. 000-52294).

· The company’s current report on Form 8-K filed with the Commission on April 27, 2009 (File No. 000-52294).

· The company’s current report on Form 8-K filed with the Commission on May 14, 2009 (File No. 000-52294).

· The company’s current report on Form 8-K filed with the Commission on July 27, 2009 (File No. 000-52294).

· The company’s current report on Form 8-K filed with the Commission on August 12, 2009 (File No. 000-52294).

· The company’s current report on Form 8-K filed with the Commission on September 2, 2009 (File No. 000-52294).

· The company’s current report on Form 8-K filed with the Commission on November 12, 2009 (File No. 001-34493).

· The company’s current report on Form 8-K filed with the Commission on December 9, 2009 (File No. 001-34493).

· The company’s current report on Form 8-K filed with the Commission on December 17, 2009 (File No. 001-34493).

· The description of the Common Stock set forth in the company’s registration statement on Form 10-SB filed with the SEC under the Securities Exchange Act of 1934, or the Exchange Act, including any amendments or reports filed for the purpose of updating such description (File No. 000-52294).

· The company’s Proxy Statement for the company’s 2009, Annual Meeting of Stockholders, filed with the Commission on April 29, 2009.

· The company’s Information Statement on Schedule 14C, filed with the Commission on September 8, 2009, including any amendments or reports filed for the purpose of updating such description (File No. 001-34493).

· The company’s Registration of Securities Form 8-A filed with the Commission on October 15, 2009 (File No. 001-34493).

A statement contained in a document incorporated by reference into this prospectus shall be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus, any prospectus supplement or in any other subsequently filed document which is also incorporated in this prospectus modifies or replaces such statement. Any statements so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus.

You may request a copy of these documents, which will be provided to you at no cost, by writing or telephoning us using the following contact information: Anthony S. Loumidis, Chief Financial Officer, American DG Energy Inc., 45 First Avenue, Waltham, MA 02451, Phone: (781) 622-1117.

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WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information reporting requirements of the Exchange Act, and accordingly we file annual, quarterly and current reports, proxy statements and other information with the SEC. Members of the public may read and copy any materials we file with the SEC at the SEC’s Public Reference Room located at 100 F Street, N.E., Washington, DC 20549. Information on the operation of the Public Reference Room may be obtained by calling the SEC at 1-800-SEC-0330.

In addition, we are required to file electronic versions of these materials with the SEC through the SEC’s database system called EDGAR. Copies of this registration statement and its exhibits, as well as of our annual reports, quarterly reports, proxy statements and other filings may be examined without charge by accessing the EDGAR database at www.sec.gov and on our own website at www.americandg.com. Our website is not a part of this prospectus.

We will provide without charge to each person, including any beneficial owner, to whom this prospectus is delivered, upon written or oral request of such person, a copy of any or all of the documents incorporated by reference in this prospectus. Exhibits to the filings will not be sent, however, unless those exhibits have been specifically incorporated by reference in this prospectus.

Requests for such documents should be addressed in writing or by telephone to: Anthony S. Loumidis, Chief Financial Officer, American DG Energy Inc., 45 First Avenue, Waltham, MA 02451, Phone: (781) 622-1117.

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PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 14.  Other Expenses of Issuance and Distribution.

The following table summarizes the estimated expenses that we will incur in connection with this offering.

	Amount
Securities and Exchange Commission registration fee	$	1,860
Legal fees and expenses		5,500
Accounting fees and expenses		1,500
Miscellaneous		1,140
Total	$	10,000

Item 15. Indemnification of Directors and Officers.

Section 102 of the Delaware General Corporation Law allows a corporation to eliminate the personal liability of directors of a corporation to the corporation or its stockholders for monetary damages for a breach of fiduciary duty as a director, except where the director breached his duty of loyalty, failed to act in good faith, engaged in intentional misconduct or knowingly violated a law, authorized the payment of a dividend or approved a stock repurchase in violation of Delaware corporate law or obtained an improper personal benefit. We have included such a provision in our Restated Certificate of Incorporation.

Section 145 of the Delaware General Corporation Law provides that a corporation has the power to indemnify a director, officer, employee or agent of the corporation and certain other persons serving at the request of the corporation in related capacities against amounts paid and expenses incurred in connection with an action or proceeding to which he is or is threatened to be made a party by reason of such position, if such person shall have acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and, in any criminal proceeding, if such person had no reasonable cause to believe his conduct was unlawful; provided that, in the case of actions brought by or in the right of the corporation, no indemnification shall be made with respect to any matter as to which such person shall have been adjudged to be liable to the corporation unless and only to the extent that the adjudicating court determines that such indemnification is proper under the circumstances.

Our charter includes a provision that eliminates the personal liability of its directors for monetary damages for breach of fiduciary duty as a director, except for liability:

· for any breach of the director’s duty of loyalty to the company or its stockholders;

· for acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law;

· under section 174 of the Delaware General Corporation Law regarding unlawful dividends and stock purchases; or

· for any transaction from which the director derived an improper personal benefit.

Our Restated Certificate of Incorporation also provides that:

· we must indemnify our directors and officers to the fullest extent permitted by Delaware law;

· we may, to the extent authorized from time to time by our Board of Directors, indemnify our other employees and agents to the same extent that we indemnified our officers and directors; and

· in the event we do not assume the defense in a legal proceeding, we must advance expenses, as incurred, to our directors and executive officers in connection with a legal proceeding to the fullest extent permitted by Delaware law.

The indemnification provisions contained in our Restated Certificate of Incorporation and Amended and Restated Bylaws are not exclusive of any other rights to which a person may be entitled by law, agreement, vote of stockholders or disinterested directors or otherwise.

In addition, we maintain insurance on behalf of our directors and executive officers insuring them against any liability asserted against them in their capacities as directors or officers or arising out of such status.

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Item 16. Exhibits and Financial Statement Schedules

(a) Exhibits.

Exhibit
Number	Description
3.1#	Certificate of Incorporation, as amended and restated December 9, 2009.
3.2#	By-laws, as amended and restated August 31, 2009.
4.1	Form of Warrant (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
4.2	Warrant to Purchase Shares of Common Stock dated February 24, 2009 (incorporated by reference from the registrant’s current report on Form 8-K, filed with the SEC on February 26, 2009).
5.1#	Opinion of Sullivan & Worcester LLP dated February 3, 2010.
10.1#	Audit Committee Charter, as amended October 13, 2009.
10.2	Compensation Committee Charter (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.3#	Nominating and Governance Committee Charter dated August 31, 2009.
10.4	American Distributed Generation Inc. 2001 Stock Incentive Plan (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.5	2005 Stock Incentive Plan (incorporated by reference from our definitive proxy statement for the 2008 Annual Meeting of shareholders originally filed with the SEC on April 29, 2008).
10.6	Facilities, Support Services and Business Agreement with Tecogen Inc. (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 22, 2006. Confidential treatment has been granted for portions of this document. The confidential portions have been omitted and have been filed separately, on a confidential basis, with the SEC).
10.7	Amendment to Facilities, Support Services and Business Agreement with Tecogen Inc. dated April 1, 2008 (incorporated by reference from the registrant’s Form 10-Q, filed with the SEC on May 14, 2008, for the quarter ended March 31, 2008).
10.8	Amendment No. 2 to Facilities, Support Services and Business Agreement with Tecogen Inc. dated May 15, 2008 (incorporated by reference from the registrant’s Form 10-K, originally filed, filed with the SEC on March 20, 2009).
10.9	Amendment No. 3 to Facilities, Support Services and Business Agreement with Tecogen Inc. dated January 2, 2009 (incorporated by reference from the registrant’s Form 10-K, originally filed, filed with the SEC on March 20, 2009).
10.10	Operating Agreement of American DG New York LLC (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 22, 2006).
10.11	Form of Energy Purchase Agreement (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.12#	Form of Subscription Agreement for private placement of common stock for American Distributed Generation Inc.
10.13#	Restricted Stock Purchase Agreement with Charles T. Maxwell dated February 20, 2007.
10.14	Form of 8% Senior Convertible Debenture Due 2011 (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.15#	Form of Subscription Agreement for private placement of common stock for American DG Energy Inc.

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10.16 Form of Warrant to purchase shares of common stock, dated February 24, 2009, entered into between the company and Daniel Barnett (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on February 26, 2009).

10.17	Form of Subscription Agreement for common stock (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on April 27, 2009).
10.18	Form of Subscription Agreement for common stock (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on July 27, 2009).
10.19#	Form of Subscription Agreement for common stock (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on July 27, 2009).
10.20#	Warrant Agreement with Hayden IR dated October 1, 2009.
14.1	Code of Business Conduct and Ethics (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
16.1	Letter on change in certifying accountant (incorporated by reference from, the company’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
21.1	List of subsidiaries (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
23.1	Consent of Sullivan & Worcester LLP (included in Exhibit 5.1).
23.2#	Consent of Caturano and Company, P.C.
24.1	Power of Attorney (included on signature page).

#   Filed herewith

(b)           Financial Statement Schedules.  None

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Item 17. Undertakings

(a)   The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

i.           To include any prospectus required by section 10(a)(3) of the Securities Act of 1933;

ii.          To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

iii.         To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

Provided, however, that paragraphs (1)(i), (ii) and (iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial  bona fide  offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4)  That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

i.  If the registrant is relying on Rule 430B:

A. Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

B. Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however,  that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date; or

15

ii. If the registrant is subject to Rule 430C, each prospectus filed pursuant to Rule 424(b) as part of a registration statement relating to an offering, other than registration statements relying on Rule 430B or other than prospectuses filed in reliance on Rule 430A, shall be deemed to be part of and included in the registration statement as of the date it is first used after effectiveness.  Provided, however,  that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such first use, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such date of first use.

(5) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities: The undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(b)   The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c)   The undersigned registrant hereby undertakes to supplement the prospectus, after the expiration of the subscription period, to set forth the results of the subscription offer, the transactions by the underwriters during the subscription period, the amount of unsubscribed securities to be purchased by the underwriters, and the terms of any subsequent reoffering thereof. If any public offering by the underwriters is to be made on terms differing from those set forth on the cover page of the prospectus, a post-effective amendment will be filed to set forth the terms of such offering.

(d)   Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

16

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant has authorized this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Waltham, Massachusetts on February 3, 2010.

AMERICAN DG ENERGY INC.

By: /s/ JOHN N. HATSOPOULOS

John N. Hatsopoulos

Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

Signature	Title	Date
/s/ GEORGE N. HATSOPOULOS*	Chairman of the Board	February 3, 2010
George N. Hatsopoulos
/s/ JOHN N. HATSOPOULOS*	Chief Executive Officer (Principal Executive Officer)	February 3, 2010
John N. Hatsopoulos
/s/ ANTHONY S. LOUMIDIS	Chief Financial Officer (Principal Financial	February 3, 2010
Anthony S. Loumidis	and Accounting Officer)
/s/ EARL R. LEWIS*	Director	February 3, 2010
Earl R. Lewis
/s/ CHARLES T. MAXWELL*	Director	February 3, 2010
Charles T. Maxwell
/s/ ALAN D. WEINSTEIN*	Director	February 3, 2010
Alan D. Weinstein

* By:	/s/ ANTHONY S. LOUMIDIS
	Anthony S. Loumidis
	Attorney-in-Fact

17

EXHIBIT INDEX

Exhibit
Number	Description
3.1#	Certificate of Incorporation, as amended and restated December 9, 2009.
3.2#	By-laws, as amended and restated August 31, 2009.
4.1	Form of Warrant (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
4.2	Warrant to Purchase Shares of Common Stock dated February 24, 2009 (incorporated by reference from the registrant’s current report on Form 8-K, filed with the SEC on February 26, 2009).
5.1#	Opinion of Sullivan & Worcester LLP dated February 3, 2010.
10.1#	Audit Committee Charter, as amended October 13, 2009.
10.2	Compensation Committee Charter (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.3#	Nominating and Governance Committee Charter dated August 31, 2009.
10.4	American Distributed Generation Inc. 2001 Stock Incentive Plan (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.5	2005 Stock Incentive Plan (incorporated by reference from our definitive proxy statement for the 2008 Annual Meeting of shareholders originally filed with the SEC on April 29, 2008).
10.6	Facilities, Support Services and Business Agreement with Tecogen Inc. (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 22, 2006. Confidential treatment has been granted for portions of this document. The confidential portions have been omitted and have been filed separately, on a confidential basis, with the SEC).
10.7	Amendment to Facilities, Support Services and Business Agreement with Tecogen Inc. dated April 1, 2008 (incorporated by reference from the registrant’s Form 10-Q, filed with the SEC on May 14, 2008, for the quarter ended March 31, 2008).
10.8	Amendment No. 2 to Facilities, Support Services and Business Agreement with Tecogen Inc. dated May 15, 2008 (incorporated by reference from the registrant’s Form 10-K, originally filed, filed with the SEC on March 20, 2009).
10.9	Amendment No. 3 to Facilities, Support Services and Business Agreement with Tecogen Inc. dated January 2, 2009 (incorporated by reference from the registrant’s Form 10-K, originally filed, filed with the SEC on March 20, 2009).
10.10	Operating Agreement of American DG New York LLC (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 22, 2006).
10.11	Form of Energy Purchase Agreement (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.12#	Form of Subscription Agreement for private placement of common stock for American Distributed Generation Inc.
10.13#	Restricted Stock Purchase Agreement with Charles T. Maxwell dated February 20, 2007.
10.14	Form of 8% Senior Convertible Debenture Due 2011 (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
10.15#	Form of Subscription Agreement for private placement of common stock for American DG Energy Inc.
10.16	Form of Warrant to purchase shares of common stock, dated February 24, 2009, entered into between the company and Daniel Barnett (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on February 26, 2009).

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10.17	Form of Subscription Agreement for common stock (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on April 27, 2009).
10.18	Form of Subscription Agreement for common stock (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on July 27, 2009).
10.19#	Form of Subscription Agreement for common stock (incorporated by reference from the registrant’s current Form 8-K, originally filed with the SEC on July 27, 2009).
10.20#	Warrant Agreement with Hayden IR dated October 1, 2009.
14.1	Code of Business Conduct and Ethics (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
16.1	Letter on change in certifying accountant (incorporated by reference from, the company’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
21.1	List of subsidiaries (incorporated by reference from the registrant’s Form 10-SB, as amended, originally filed with the SEC on November 2, 2006).
23.1	Consent of Sullivan & Worcester LLP (included in Exhibit 5.1).
23.2#	Consent of Caturano and Company, P.C.
24.1	Power of Attorney (included on signature page).

#   Filed herewith

19

EX-3.1

Exhibit 3.1

AMENDED AND RESTATED

CERTIFICATE OF INCORPORATION

OF

AMERICAN DG ENERGY INC.

(Originally incorporated on July 24, 2001 as Virtual Electric Inc.)

American DG Energy Inc., a corporation organized and existing under the laws of the State of Delaware (the “Corporation”), hereby certifies as follows:

1.           Pursuant to Section 242 and 245 of the General Corporation Law of the State of Delaware, this Amended and Restated Certificate of Incorporation restates, integrates and further amends the provisions of the Corporation’s Certificate of Incorporation, as amended to the date of this filing. The original Certificate of Incorporation was filed with the Secretary of State of Delaware on July 24, 2001. This Amended and Restated Certificate of Incorporation has been duly adopted and approved by the written consent of the directors and stockholders of the Corporation.

2.           The text of the Certificate of Incorporation, as amended to the date of this filing, is hereby restated and amended to read in its entirety as follows:

First:     The name of the Corporation is American DG Energy Inc.

Second: The address of the Corporation’s registered office in the State of Delaware is 1209 Orange Street, City of Wilmington, County of New Castle, Zip Code 19801, and the name of the registered agent of this Corporation in the State of Delaware at such address is The Corporation Trust Company.

Third:   The nature of the business or purposes to be conducted or promoted by the Corporation is to engage in any lawful act or activity for which corporations may be organized under the General Corporation Law of Delaware.

Fourth: The total number of shares of all classes of stock that the Corporation shall have authority to issue is 110,000,000 shares, consisting of (i) 100,000,000 shares of Common Stock, $.001 par value per share (“Common Stock”), and (ii) 10,000,000 shares of Preferred Stock, $.001 par value per share (“Preferred Stock”), all of which Preferred Stock will be undesignated.

The following is a statement of the designations and the powers, privileges and rights, and the qualifications, limitations or restrictions thereof in respect of each class of capital stock of the Corporation.

A. COMMON STOCK.

1.      General.  The voting, dividend and liquidation rights of the holders of the Common Stock are subject to and qualified by the rights of the holders of the Preferred Stock of any series as may be designated by the Board of Directors upon any issuance of the Preferred Stock of any series.

2.      Voting.  The holders of the Common Stock shall have voting rights at all meetings of stockholders, each such holder being entitled to one vote for each share thereof held by such holder; provided, however, that, except as otherwise required by law, holders of Common Stock shall not be entitled to vote on any amendment to this Certificate of Incorporation (which, as used herein, shall mean the certificate of incorporation of the Corporation, as amended from time to time, including the terms of any certificate of designations of any series of Preferred Stock) that relates solely to the terms of one or more outstanding series of Preferred Stock if the holders of such affected series are entitled, either separately or together as a class with the holders of one or more other such series, to vote thereon pursuant to this Certificate of Incorporation. There shall be no cumulative voting.

The number of authorized shares of Common Stock may be increased or decreased (but not below the number of shares thereof then outstanding) by the affirmative vote of the holders of a majority of the stock of the Corporation entitled to vote, irrespective of the provisions of Section 242(b)(2) of the General Corporation Law of Delaware.

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3.      Dividends.  Dividends may be declared and paid on the Common Stock from funds lawfully available therefor as and when determined by the Board of Directors and subject to any preferential dividend or other rights of any then outstanding Preferred Stock.

4.      Liquidation.  Upon the dissolution or liquidation of the Corporation, whether voluntary or involuntary, holders of Common Stock will be entitled to receive all assets of the Corporation available for distribution to its stockholders, subject to any preferential or other rights of any then outstanding Preferred Stock.

B. PREFERRED STOCK.

Preferred Stock may be issued from time to time in one or more series, each of such series to have such terms as stated or expressed herein and in the resolution or resolutions providing for the issue of such series adopted by the Board of Directors of the Corporation as hereinafter provided. Any shares of Preferred Stock that may be redeemed, purchased or acquired by the Corporation may be reissued except as otherwise provided by law.

Authority is hereby expressly granted to the Board of Directors from time to time to issue the Preferred Stock in one or more series, and in connection with the creation of any such series, by resolution or resolutions providing for the issuance of the shares thereof, to determine and fix the number of shares of such series and such voting powers, full or limited, or no voting powers, and such designations, preferences and relative participating, optional or other special rights, and qualifications, limitations or restrictions thereof, including dividend rights, conversion rights, redemption privileges and liquidation preferences, as shall be stated and expressed in such resolutions, all to the full extent now or hereafter permitted by the General Corporation Law of Delaware. Without limiting the generality of the foregoing, the resolutions providing for issuance of any series of Preferred Stock may provide that such series shall be superior or rank equally or be junior to the Preferred Stock of any other series to the extent permitted by law.

The number of authorized shares of Preferred Stock may be increased or decreased (but not below the number of shares then outstanding) by the affirmative vote of the holders of a majority of the stock of the Corporation entitled to vote, irrespective of the provisions of Section 242(b)(2) of the General Corporation Law of Delaware.

Fifth:  Except as otherwise provided herein, the Corporation reserves the right to amend, alter, change or repeal any provision contained in this Certificate of Incorporation, in the manner now or hereafter prescribed by statute and this Certificate of Incorporation, and all rights conferred upon stockholders herein are granted subject to this reservation.

Sixth:  In furtherance and not in limitation of the powers conferred upon it by the laws of the State of Delaware, and subject to the terms of any series of Preferred Stock, the Board of Directors shall have the power to adopt, amend, alter or repeal the Corporation’s By-laws. The affirmative vote of a majority of the directors present at any regular or special meeting of the Board of Directors at which a quorum is present shall be required to adopt, amend, alter or repeal the Corporation’s By-laws. The Corporation’s By-laws also may be adopted, amended, altered or repealed by the affirmative vote of the holders of at least 75% of the votes that all the stockholders would be entitled to cast in any annual election of directors or class of directors, in addition to any other vote required by this Certificate of Incorporation. Notwithstanding any other provisions of law, this Certificate of Incorporation or the By-Laws of the Corporation, and notwithstanding the fact that a lesser percentage may be specified by law, the affirmative vote of the holders of at least 75% of the votes that all the stockholders would be entitled to cast in any annual election of directors or class of directors shall be required to amend or repeal, or to adopt any provision inconsistent with, this Article Sixth.

Seventh:  Except to the extent that the General Corporation Law of Delaware prohibits the elimination or limitation of liability of directors for breaches of fiduciary duty, no director of the Corporation shall be personally liable to the Corporation or its stockholders for monetary damages for any breach of fiduciary duty as a director, notwithstanding any provision of law imposing such liability. No amendment to or repeal of this provision shall apply to or have any effect on the liability or alleged liability of any director of the Corporation for or with respect to any acts or omissions of such director occurring prior to such amendment or repeal.

Eighth:  The Corporation shall provide indemnification as follows:

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1.           Actions, Suits and Proceedings Other than by or in the Right of the Corporation.  The Corporation shall indemnify each person who was or is a party or threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the Corporation) by reason of the fact that he or she is or was, or has agreed to become, a director or officer of the Corporation, or is or was serving, or has agreed to serve, at the request of the Corporation, as a director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint venture, trust or other enterprise (including any employee benefit plan) (all such persons being referred to hereafter as an “Indemnitee”), or by reason of any action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by or on behalf of Indemnitee in connection with such action, suit or proceeding and any appeal therefrom, if Indemnitee acted in good faith and in a manner that Indemnitee reasonably believed to be in, or not opposed to, the best interests of the Corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful. The termination of any action, suit or proceeding by judgment, order, settlement, conviction or upon a plea of nolo contendere or its equivalent, shall not, of itself, create a presumption that Indemnitee did not act in good faith and in a manner that Indemnitee reasonably believed to be in, or not opposed to, the best interests of the Corporation, and, with respect to any criminal action or proceeding, had reasonable cause to believe that his or her conduct was unlawful.

2.           Actions or Suits by or in the Right of the Corporation.  The Corporation shall indemnify any Indemnitee who was or is a party to or threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the Corporation to procure a judgment in its favor by reason of the fact that Indemnitee is or was, or has agreed to become, a director or officer of the Corporation, or is or was serving, or has agreed to serve, at the request of the Corporation, as a director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint venture, trust or other enterprise (including any employee benefit plan), or by reason of any action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys’ fees) and, to the extent permitted by law, amounts paid in settlement actually and reasonably incurred by or on behalf of Indemnitee in connection with such action, suit or proceeding and any appeal therefrom, if Indemnitee acted in good faith and in a manner that Indemnitee reasonably believed to be in, or not opposed to, the best interests of the Corporation, except that no indemnification shall be made under this Section 2 in respect of any claim, issue or matter as to which Indemnitee shall have been adjudged to be liable to the Corporation, unless, and only to the extent, that the Court of Chancery of Delaware shall determine upon application that, despite the adjudication of such liability but in view of all the circumstances of the case, Indemnitee is fairly and reasonably entitled to indemnity for such expenses (including attorneys’ fees) that the Court of Chancery of Delaware shall deem proper.

3.           Indemnification for Expenses of Successful Party.  Notwithstanding any other provisions of this Article, to the extent that an Indemnitee has been successful, on the merits or otherwise, in defense of any action, suit or proceeding referred to in Sections 1 and 2 of this Article Eighth, or in defense of any claim, issue or matter therein, or on appeal from any such action, suit or proceeding, Indemnitee shall be indemnified against all expenses (including attorneys’ fees) actually and reasonably incurred by or on behalf of Indemnitee in connection therewith. Without limiting the foregoing, if any action, suit or proceeding is disposed of, on the merits or otherwise (including a disposition without prejudice), without (i) the disposition being adverse to Indemnitee, (ii) an adjudication that Indemnitee was liable to the Corporation, (iii) a plea of guilty or nolo contendere by Indemnitee, (iv) an adjudication that Indemnitee did not act in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the Corporation, and (v) with respect to any criminal proceeding, an adjudication that Indemnitee had reasonable cause to believe his conduct was unlawful, Indemnitee shall be considered for the purposes hereof to have been wholly successful with respect thereto.

4.           Notification and Defense of Claim.  As a condition precedent to an Indemnitee’s right to be indemnified, such Indemnitee must notify the Corporation in writing as soon as practicable of any action, suit, proceeding or investigation involving such Indemnitee for which indemnity will or could be sought. With respect to any action, suit, proceeding or investigation of which the Corporation is so notified, the Corporation will be entitled to participate therein at its own expense and/or to assume the defense thereof at its own expense, with legal counsel reasonably acceptable to Indemnitee. After notice from the Corporation to Indemnitee of its election so to assume such defense, the Corporation shall not be liable to Indemnitee for any legal or other expenses subsequently incurred by Indemnitee in connection with such action, suit, proceeding or investigation, other than as provided below in this Section 4. Indemnitee shall have the right to employ his or her own counsel in connection with such action, suit, proceeding or investigation, but the fees and expenses of such counsel incurred after notice from the Corporation of its assumption of the defense thereof shall be at the expense of Indemnitee unless (i) the employment of counsel by Indemnitee has been authorized by the Corporation, (ii) counsel to Indemnitee shall have reasonably concluded that there may be a conflict of interest or position on any significant issue between the Corporation and Indemnitee in the conduct of the defense of such action, suit, proceeding or investigation or (iii) the Corporation shall not in fact have employed counsel to assume the defense of such action, suit, proceeding or investigation, in each of which cases the fees and expenses of counsel for Indemnitee shall be at the expense of the Corporation, except as otherwise expressly provided by this Article. The Corporation shall not be entitled, without the consent of Indemnitee, to assume the defense of any claim brought by or in the right of the Corporation or as to which counsel for Indemnitee shall have reasonably made the conclusion provided for in clause (ii) above. The Corporation shall not be required to indemnify Indemnitee under this Article Eighth for any amounts paid in settlement of any action, suit, proceeding or investigation effected without its written consent. The Corporation shall not settle any action, suit, proceeding or investigation in any manner that would impose any penalty or limitation on Indemnitee without Indemnitee’s written consent. Neither the Corporation nor Indemnitee will unreasonably withhold or delay its consent to any proposed settlement.

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5.           Advance of Expenses.  Subject to the provisions of Section 6 of this Article Eighth, in the event of any action, suit, proceeding or investigation of which the Corporation receives notice under this Article, any expenses (including attorneys’ fees) incurred by or on behalf of Indemnitee in defending an action, suit, proceeding or investigation or any appeal therefrom shall be paid by the Corporation in advance of the final disposition of such matter; provided, however, that the payment of such expenses incurred by or on behalf of Indemnitee in advance of the final disposition of such matter shall be made only upon receipt of an undertaking by or on behalf of Indemnitee to repay all amounts so advanced in the event that it shall ultimately be determined that Indemnitee is not entitled to be indemnified by the Corporation as authorized in this Article; and further provided that no such advancement of expenses shall be made under this Article Eighth if it is determined (in the manner described in Section 6) that (i) Indemnitee did not act in good faith and in a manner he reasonably believed to be in, or not opposed to, the best interests of the Corporation, or (ii) with respect to any criminal action or proceeding, Indemnitee had reasonable cause to believe his conduct was unlawful. Such undertaking shall be accepted without reference to the financial ability of Indemnitee to make such repayment.

6.           Procedure for Indemnification.  In order to obtain indemnification or advancement of expenses pursuant to Section 1, 2, 3 or 5 of this Article Eighth, an Indemnitee shall submit to the Corporation a written request. Any such advancement of expenses shall be made promptly, and in any event within 60 days after receipt by the Corporation of the written request of Indemnitee, unless (i) the Corporation has assumed the defense pursuant to Section 4 of this Article Eighth (and none of the circumstances described in Section 4 of this Article Eighth that would nonetheless entitle the Indemnitee to indemnification for the fees and expenses of separate counsel have occurred) or (ii) the Corporation determines within such 60-day period that Indemnitee did not meet the applicable standard of conduct set forth in Section 1, 2 or 5 of this Article Eighth, as the case may be. Any such indemnification, unless ordered by a court, shall be made with respect to requests under Section 1 or 2 only as authorized in the specific case upon a determination by the Corporation that the indemnification of Indemnitee is proper because Indemnitee has met the applicable standard of conduct set forth in Section 1 or 2, as the case may be. Such determination shall be made in each instance (a) by a majority vote of the directors of the Corporation consisting of persons who are not at that time parties to the action, suit or proceeding in question (“disinterested directors”), whether or not a quorum, (b) by a committee of disinterested directors designated by majority vote of disinterested directors, whether or not a quorum, (c) if there are no disinterested directors, or if the disinterested directors so direct, by independent legal counsel (who may, to the extent permitted by law, be regular legal counsel to the Corporation) in a written opinion, or (d) by the stockholders of the Corporation.

7.           Remedies.  The right to indemnification or advancement of expenses as granted by this Article shall be enforceable by Indemnitee in any court of competent jurisdiction. Neither the failure of the Corporation to have made a determination prior to the commencement of such action that indemnification is proper in the circumstances because Indemnitee has met the applicable standard of conduct, nor an actual determination by the Corporation pursuant to Section 6 of this Article Eighth that Indemnitee has not met such applicable standard of conduct, shall be a defense to the action or create a presumption that Indemnitee has not met the applicable standard of conduct. Indemnitee’s expenses (including attorneys’ fees) reasonably incurred in connection with successfully establishing Indemnitee’s right to indemnification, in whole or in part, in any such proceeding shall also be indemnified by the Corporation.

8.           Limitations.  Notwithstanding anything to the contrary in this Article, except as set forth in Section 7 of the Article Eighth, the Corporation shall not indemnify an Indemnitee pursuant to this Article Eighth in connection with a proceeding (or part thereof) initiated by such Indemnitee unless the initiation thereof was approved by the Board of Directors of the Corporation. Notwithstanding anything to the contrary in this Article, the Corporation shall not indemnify an Indemnitee to the extent such Indemnitee is reimbursed from the proceeds of insurance, and in the event the Corporation makes any indemnification payments to an Indemnitee and such Indemnitee is subsequently reimbursed from the proceeds of insurance, such Indemnitee shall promptly refund indemnification payments to the Corporation to the extent of such insurance reimbursement.

9.           Subsequent Amendment.  No amendment, termination or repeal of this Article or of the relevant provisions of the General Corporation Law of Delaware or any other applicable laws shall affect or diminish in any way the rights of any Indemnitee to indemnification under the provisions hereof with respect to any action, suit, proceeding or investigation arising out of or relating to any actions, transactions or facts occurring prior to the final adoption of such amendment, termination or repeal.

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10.           Other Rights.  The indemnification and advancement of expenses provided by this Article shall not be deemed exclusive of any other rights to which an Indemnitee seeking indemnification or advancement of expenses may be entitled under any law (common or statutory), agreement or vote of stockholders or disinterested directors or otherwise, both as to action in Indemnitee’s official capacity and as to action in any other capacity while holding office for the Corporation, and shall continue as to an Indemnitee who has ceased to be a director or officer, and shall inure to the benefit of the estate, heirs, executors and administrators of Indemnitee. Nothing contained in this Article shall be deemed to prohibit, and the Corporation is specifically authorized to enter into, agreements with officers and directors providing indemnification rights and procedures different from those set forth in this Article. In addition, the Corporation may, to the extent authorized from time to time by its Board of Directors, grant indemnification rights to other employees or agents of the Corporation or other persons serving the Corporation and such rights may be equivalent to, or greater or less than, those set forth in this Article.

11.           Partial Indemnification.  If an Indemnitee is entitled under any provision of this Article to indemnification by the Corporation for some or a portion of the expenses (including attorneys’ fees), judgments, fines or amounts paid in settlement actually and reasonably incurred by or on behalf of Indemnitee in connection with any action, suit, proceeding or investigation and any appeal therefrom but not, however, for the total amount thereof, the Corporation shall nevertheless indemnify Indemnitee for the portion of such expenses (including attorneys’ fees), judgments, fines or amounts paid in settlement to which Indemnitee is entitled.

12.           Insurance.  The Corporation may purchase and maintain insurance, at its expense, to protect itself and any director, officer, employee or agent of the Corporation or another corporation, partnership, joint venture, trust or other enterprise (including any employee benefit plan) against any expense, liability or loss incurred by him in any such capacity, or arising out of his status as such, whether or not the Corporation would have the power to indemnify such person against such expense, liability or loss under the General Corporation Law of Delaware.

13.           Savings Clause.  If this Article or any portion hereof shall be invalidated on any ground by any court of competent jurisdiction, then the Corporation shall nevertheless indemnify each Indemnitee as to any expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement in connection with any action, suit, proceeding or investigation, whether civil, criminal or administrative, including an action by or in the right of the Corporation, to the fullest extent permitted by any applicable portion of this Article that shall not have been invalidated and to the fullest extent permitted by applicable law.

14.           Definitions.  Terms used herein and defined in Section 145(h) and Section 145(i) of the General Corporation Law of Delaware shall have the respective meanings assigned to such terms in such Section 145(h) and Section 145(i).

Ninth:  This Article is inserted for the management of the business and for the conduct of the affairs of the Corporation.

1.           General Powers.  The business and affairs of the Corporation shall be managed by or under the direction of the Board of Directors.

2.           Number of Directors; Election of Directors.  Subject to the rights of holders of any series of Preferred Stock to elect directors, the number of directors of the Corporation shall be established by the Board of Directors. Election of directors need not be by written ballot, except as and to the extent provided in the By-laws of the Corporation.

3.           Classes of Directors.  Subject to the rights of holders of any series of Preferred Stock to elect directors, the Board of Directors shall consist of one class.

4.           Terms of Office.  Subject to the rights of holders of any series of Preferred Stock to elect directors, each director shall serve for a term ending on the date of the next annual meeting following the annual meeting at which such director was elected; provided that the term of any person who is a director of the Corporation on the date of filing of this Amended and Restated Certificate of Incorporation with the Secretary of State of Delaware shall expire at the Corporation’s annual meeting of stockholders held in 2006; and provided further that the term of each director shall continue until the election and qualification of his successor and be subject to his earlier death, resignation or removal.

5.           Quorum.  The greater of (a) a majority of the directors at any time in office and (b) one-third of the number of directors fixed pursuant to Section 2 of this Article Ninth shall constitute a quorum. If at any meeting of the Board of Directors there shall be less than such a quorum, a majority of the directors present may adjourn the meeting from time to time without further notice other than announcement at the meeting, until a quorum shall be present.

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6.           Action at Meeting.  Every act, or decision done or made by a majority of the directors present at a meeting duly held at which a quorum is present shall be regarded as the act of the Board of Directors unless a greater number is required by law or by this Certificate of Incorporation.

7.           Removal.  Subject to the rights of holders of any series of Preferred Stock, directors of the Corporation may be removed only for cause and only by the affirmative vote of the holders of at least 75% of the votes that all the stockholders would be entitled to cast in any annual election of directors.

8.           Vacancies.  Subject to the rights of holders of any series of Preferred Stock, any vacancy or newly created directorships in the Board of Directors, however occurring, shall be filled only by vote of a majority of the directors then in office, although less than a quorum, or by a sole remaining director and shall not be filled by the stockholders. A director elected to fill a vacancy shall hold office until the next annual election of directors, subject to the election and qualification of a successor and to such director’s earlier death, resignation or removal.

9.           Stockholder Nominations and Introduction of Business, Etc.  Advance notice of stockholder nominations for election of directors and other business to be brought by stockholders before a meeting of stockholders shall be given in the manner provided by the By-laws of the Corporation.

10.         Amendments to Article.  Notwithstanding any other provisions of law, this Certificate of Incorporation or the By-laws of the Corporation, and notwithstanding the fact that a lesser percentage may be specified by law, the affirmative vote of the holders of at least 75% of the votes that all the stockholders would be entitled to cast in any annual election of directors shall be required to amend or repeal, or to adopt any provision inconsistent with, this Article Ninth.

Tenth:  Stockholders of the Corporation may not take any action by written consent in lieu of a meeting. Notwithstanding any other provisions of law, this Certificate of Incorporation or the By-laws of the Corporation, and notwithstanding the fact that a lesser percentage may be specified by law, the affirmative vote of the holders of at least 75% of the votes that all the stockholders would be entitled to cast in any annual election of directors or class of directors shall be required to amend or repeal, or to adopt any provision inconsistent with, this Article Tenth.

Eleventh:  Special meetings of stockholders for any purpose or purposes may be called at any time by the Board of Directors, the Chairman of the Board or the President, but such special meetings may not be called by any other person or persons. Business transacted at any special meeting of stockholders shall be limited to matters relating to the purpose or purposes stated in the notice of meeting. Notwithstanding any other provision of law, this Certificate of Incorporation or the By-laws of the Corporation, and notwithstanding the fact that a lesser percentage may be specified by law, the affirmative vote of the holders of at least 75% of the votes that all the stockholders would be entitled to cast in any annual election of directors or class of directors shall be required to amend or repeal, or to adopt any provision inconsistent with, this Article Eleventh.

IN WITNESS WHEREOF, this Certificate of Incorporation, which has been duly adopted in accordance with Sections 228, 242 and 245 of the Delaware General Corporation Law, has been executed by its duly authorized officer this December 9, 2009.

AMERICAN DG ENERGY INC.
By:	/s/ John N. Hatsopoulos
Name:	John N. Hatsopoulos
Title:	Chief Executive Officer

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EX-3.2

Exhibit 3.2

AMENDED AND RESTATED BY-LAWS

OF

AMERICAN DG ENERGY INC.

(as of August 31, 2009)

ARTICLE I.

STOCKHOLDERS

        1.1    Place of Meetings.    All meetings of stockholders shall be held at such place as may be designated from time to time by the Board of Directors, the Chairman of the Board, the Chief Executive Officer or the President or, if not so designated, at the principal office of the corporation.

        1.2    Annual Meeting.    The annual meeting of stockholders for the election of directors and for the transaction of such other business as may properly be brought before the meeting shall be held on a date and at a time designated by the Board of Directors, the Chairman of the Board, the Chief Executive Officer or the President (which date shall not be a legal holiday in the place where the meeting is to be held). If no annual meeting is held in accordance with the foregoing provisions, a special meeting may be held in lieu of the annual meeting, and any action taken at that special meeting shall have the same effect as if it had been taken at the annual meeting, and in such case all references in these By-laws to the annual meeting of the stockholders shall be deemed to refer to such special meeting.

        1.3    Special Meetings.    Special meetings of stockholders for any purpose or purposes may be called at any time by the Board of Directors, the Chairman of the Board, the Chief Executive Officer or the President, but such special meetings may not be called by any other person or persons. Business transacted at any special meeting of stockholders shall be limited to matters relating to the purpose or purposes stated in the notice of meeting.

        1.4    Notice of Meetings.    Except as otherwise provided by law, notice of each meeting of stockholders, whether annual or special, shall be given not less than 10 nor more than 60 days before the date of the meeting to each stockholder entitled to vote at such meeting. Without limiting the manner by which notice otherwise may be given to stockholders, any notice shall be effective if given by a form of electronic transmission consented to (in a manner consistent with the General Corporation Law of the State of Delaware) by the stockholder to whom the notice is given. The notices of all meetings shall state the place, date and time of the meeting and the means of remote communications, if any, by which stockholders and proxy holders may be deemed to be present in person and vote at such meeting. The notice of a special meeting shall state, in addition, the purpose or purposes for which the meeting is called. If notice is given by mail, such notice shall be deemed given when deposited in the United States mail, postage prepaid, directed to the stockholder at such stockholder's address as it appears on the records of the corporation. If notice is given by electronic transmission, such notice shall be deemed given at the time specified in Section 232 of the General Corporation Law of the State of Delaware.

        1.5    Voting List.    The Secretary shall prepare, at least 10 days before every meeting of stockholders, a complete list of the stockholders entitled to vote at the meeting, arranged in alphabetical order, and showing the address of each stockholder and the number of shares registered in the name of each stockholder. Such list shall be open to the examination of any stockholder, for any purpose germane to the meeting, for a period of at least 10 days prior to the meeting: (a) on a reasonably accessible electronic network, provided that the information required to gain access to such list is provided with notice of the meeting, or (b) during ordinary business hours, at the principal place of business of the corporation. The list shall also be produced and kept at the time and place of the meeting during the whole time thereof, and may be inspected by any stockholder who is present.

        1.6    Quorum.    Except as otherwise provided by law, the Certificate of Incorporation or these By-laws, the holders of a majority in voting power of the shares of the capital stock of the corporation issued and outstanding and entitled to vote at the meeting, present in person, present by means of remote communication in a manner, if any, authorized by the Board of Directors in its sole discretion, or represented by proxy, shall constitute a quorum for the transaction of business. A quorum, once established at a meeting, shall not be broken by the withdrawal of enough votes to leave less than a quorum.

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        1.7    Adjournments.    Any meeting of stockholders may be adjourned from time to time to any other time and to any other place at which a meeting of stockholders may be held under these By-laws by the stockholders present or represented at the meeting and entitled to vote, although less than a quorum, or, if no stockholder is present, by any officer entitled to preside at or to act as secretary of such meeting. It shall not be necessary to notify any stockholder of any adjournment of less than 30 days if the time and place of the adjourned meeting, and the means of remote communication, if any, by which stockholders and proxy holders may be deemed to be present in person and vote at such adjourned meeting, are announced at the meeting at which adjournment is taken, unless after the adjournment a new record date is fixed for the adjourned meeting. At the adjourned meeting, the corporation may transact any business that might have been transacted at the original meeting.

        1.8    Voting and Proxies.    Each stockholder shall have one vote for each share of stock entitled to vote held of record by such stockholder and a proportionate vote for each fractional share so held, unless otherwise provided by law or the Certificate of Incorporation. Each stockholder of record entitled to vote at a meeting of stockholders may vote in person (including by means of remote communications, if any, by which stockholders may be deemed to be present in person and vote at such meeting) or may authorize another person or persons to vote for such stockholder by a proxy executed or transmitted in a manner permitted by the General Corporation Law of the State of Delaware by the stockholder or such stockholder's authorized agent and delivered (including by electronic transmission) to the Secretary of the corporation. No such proxy shall be voted upon after three years from the date of its execution, unless the proxy expressly provides for a longer period.

        1.9    Action at Meeting.    When a quorum is present at any meeting, any matter other than the election of directors to be voted upon by the stockholders at such meeting shall be decided by the affirmative vote of the holders of a majority in voting power of the shares of stock present or represented and voting on such matter (or if there are two or more classes of stock entitled to vote as separate classes, then in the case of each such class, the holders of a majority in voting power of the shares of stock of that class present or represented and voting on such matter), except when a different vote is required by law, the Certificate of Incorporation or these By-laws. When a quorum is present at any meeting, any election by stockholders of directors shall be determined by a plurality of the votes cast by the stockholders entitled to vote on the election.

        1.10    Nomination of Directors.   

        (a)   Except for (1) any directors entitled to be elected by the holders of preferred stock, (2) any directors elected in accordance with Section 2.8 hereof by the Board of Directors to fill a vacancy or newly-created directorships or (3) as otherwise required by applicable law or stock market regulation, only persons who are nominated in accordance with the procedures in this Section 1.10 shall be eligible for election as directors. Nomination for election to the Board of Directors at a meeting of stockholders may be made (i) by or at the direction of the Board of Directors or (ii) by any stockholder of the corporation who (x) complies with the notice procedures set forth in Section 1.10(b) and (y) is a stockholder of record on the date of the giving of such notice and on the record date for the determination of stockholders entitled to vote at such meeting.

        (b)   To be timely, a stockholder's notice must be received in writing by the Secretary at the principal executive offices of the corporation as follows: (i) in the case of an election of directors at an annual meeting of stockholders, not less than 90 days nor more than 120 days prior to the first anniversary of the preceding year's annual meeting; provided, however, that in the event that the date of the annual meeting is advanced by more than 20 days, or delayed by more than 60 days, from the first anniversary of the preceding year's annual meeting, a stockholder's notice must be so received no earlier than the 120th day prior to such annual meeting and not later than the close of business on the later of (A) the 90th day prior to such annual meeting and (B) the tenth day following the day on which notice of the date of such annual meeting was mailed or public disclosure of the date of such annual meeting was made, whichever first occurs; or (ii) in the case of an election of directors at a special meeting of stockholders, provided that the Board of Directors has determined that directors shall be elected at such meeting, not earlier than the 120th day prior to such special meeting and not later than the close of business on the later of (x) the 90th day prior to such special meeting and (y) the tenth day following the day on which notice of the date of such special meeting was mailed or public disclosure of the date of such special meeting was made, whichever first occurs. In no event shall the adjournment or postponement of an annual meeting (or the public announcement thereof) commence a new time period (or extend any time period) for the giving of a stockholder's notice.

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The stockholder's notice to the Secretary shall set forth: (A) as to each proposed nominee (1) such person's name, age, business address and, if known, residence address, (2) such person's principal occupation or employment, (3) the class and number of shares of stock of the corporation that are beneficially owned by such person, and (4) any other information concerning such person that must be disclosed as to nominees in proxy solicitations pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended (the "Exchange Act"); (B) as to the stockholder giving the notice (1) such stockholder's name and address, as they appear on the corporation's books, (2) the class and number of shares of stock of the corporation that are owned, beneficially and of record, by such stockholder, (3) a description of all arrangements or understandings between such stockholder and each proposed nominee and any other person or persons (including their names) pursuant to which the nomination(s) are to be made by such stockholder, (4) a representation that such stockholder intends to appear in person or by proxy at the meeting to nominate the person(s) named in its notice and (5) a representation whether the stockholder intends or is part of a group that intends (x) to deliver a proxy statement and/or form of proxy to holders of at least the percentage of the corporation's outstanding capital stock required to elect the nominee and/or (y) otherwise to solicit proxies from stockholders in support of such nomination; and (C) as to the beneficial owner, if any, on whose behalf the nomination is being made (1) such beneficial owner's name and address, (2) the class and number of shares of stock of the corporation that are beneficially owned by such beneficial owner, (3) a description of all arrangements or understandings between such beneficial owner and each proposed nominee and any other person or persons (including their names) pursuant to which the nomination(s) are to be made and (4) a representation whether the beneficial owner intends or is part of a group that intends (x) to deliver a proxy statement and/or form of proxy to holders of at least the percentage of the corporation's outstanding capital stock requirement to elect the nominee and/or (y) otherwise to solicit proxies from stockholders in support of such nomination. In addition, to be effective, the stockholder's notice must be accompanied by the written consent of the proposed nominee to serve as a director if elected. The corporation may require any proposed nominee to furnish such other information as may reasonably be required to determine the eligibility of such proposed nominee to serve as a director of the corporation. A stockholder shall not have complied with this Section 1.10(b) if the stockholder (or beneficial owner, if any, on whose behalf the nomination is made) solicits or does not solicit, as the case may be, proxies in support of such stockholder's nominee in contravention of the representations with respect thereto required by this Section 1.10.

        (c)   The chairman of any meeting shall have the power and duty to determine whether a nomination was made in accordance with the provisions of this Section 1.10 (including whether the stockholder or beneficial owner, if any, on whose behalf the nomination is made solicited (or is part of a group that solicited) or did not so solicit, as the case may be, proxies in support of such stockholder's nominee in compliance with the representations with respect thereto required by this Section 1.10), and if the chairman should determine that a nomination was not made in accordance with the provisions of this Section 1.10, the chairman shall so declare to the meeting and such nomination shall be disregarded.

        (d)   Except as otherwise required by law, nothing in this Section 1.10 shall obligate the corporation or the Board of Directors to include in any proxy statement or other stockholder communication distributed on behalf of the corporation or the Board of Directors information with respect to any nominee for director submitted by a stockholder.

        (e)   Notwithstanding the foregoing provisions of this Section 1.10, if the stockholder (or a qualified representative of the stockholder) does not appear at the annual or special meeting of stockholders of the corporation to present a nomination, such nomination shall be disregarded, notwithstanding that proxies in respect of such vote may have been received by the corporation. For purposes of this Section 1.10, to be considered a qualified representative of the stockholder, a person must be authorized by a written instrument executed by such stockholder or an electronic transmission delivered by such stockholder to act for such stockholder as proxy at the meeting of stockholders and such person must produce such written instrument or electronic transmission, or a reliable reproduction of the written instrument or electronic transmission, at the meeting of stockholders.

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        (f)    For purposes of this Section 1.10, "public disclosure" shall include disclosure in a press release reported by the Dow Jones News Service, Associated Press or comparable national news service or in a document publicly filed by the corporation with the Securities and Exchange Commission pursuant to Section 13, 14 or 15(d) of the Exchange Act.

        1.11    Notice of Business at Annual Meetings.   

        (a)   At any annual meeting of the stockholders, only such business shall be conducted as shall have been properly brought before the meeting. To be properly brought before an annual meeting, business must be (1) specified in the notice of meeting (or any supplement thereto) given by or at the direction of the Board of Directors, (2) otherwise properly brought before the meeting by or at the direction of the Board of Directors, or (3) properly brought before the meeting by a stockholder. For business to be properly brought before an annual meeting by a stockholder, (i) if such business relates to the nomination of a person for election as a director of the corporation, the procedures in Section 1.10 must be complied with and (ii) if such business relates to any other matter, the business must constitute a proper matter under Delaware law for stockholder action and the stockholder must (x) have given timely notice thereof in writing to the Secretary in accordance with the procedures set forth in Section 1.11(b) and (y) be a stockholder of record on the date of the giving of such notice and on the record date for the determination of stockholders entitled to vote at such annual meeting.

        (b)   To be timely, a stockholder's notice must be received in writing by the Secretary at the principal executive offices of the corporation not less than 90 days nor more than 120 days prior to the first anniversary of the preceding year's annual meeting; provided, however, that in the event that the date of the annual meeting is advanced by more than 20 days, or delayed by more than 60 days, from the first anniversary of the preceding year's annual meeting, a stockholder's notice must be so received no earlier than the 120th day prior to such annual meeting and not later than the close of business on the later of (A) the 90th day prior to such annual meeting and (B) the tenth day following the day on which notice of the date of such annual meeting was mailed or public disclosure of the date of such annual meeting was made, whichever first occurs. In no event shall the adjournment or postponement of an annual meeting (or the public announcement thereof) commence a new time period (or extend any time period) for the giving of a stockholder's notice.

The stockholder's notice to the Secretary shall set forth as to each matter the stockholder proposes to bring before the annual meeting (1) a brief description of the business desired to be brought before the annual meeting, the text relating to the business (including the text of any resolutions proposed for consideration and in the event that such business includes a proposal to amend the By-laws, the language of the proposed amendment), and the reasons for conducting such business at the annual meeting, (2) the name and address, as they appear on the corporation's books, of the stockholder proposing such business, and the name and address of the beneficial owner, if any, on whose behalf the proposal is made, (3) the class and number of shares of stock of the corporation that are owned, of record and beneficially, by the stockholder and beneficial owner, if any, (4) a description of all arrangements or understandings between such stockholder or such beneficial owner, if any, and any other person or persons (including their names) in connection with the proposal of such business by such stockholder and any material interest of the stockholder or such beneficial owner, if any, in such business, (5) a representation that such stockholder intends to appear in person or by proxy at the annual meeting to bring such business before the meeting and (6) a representation whether the stockholder or the beneficial owner, if any, intends or is part of a group that intends (x) to deliver a proxy statement and/or form of proxy to holders of at least the percentage of the corporation's outstanding capital stock required to approve or adopt the proposal and/or (y) otherwise to solicit proxies from stockholders in support of such proposal. Notwithstanding anything in these By-laws to the contrary, no business shall be conducted at any annual meeting of stockholders except in accordance with the procedures set forth in this Section 1.11; provided that any stockholder proposal that complies with Rule 14a-8 of the proxy rules (or any successor provision) promulgated under the Securities Exchange Act of 1934, as amended, and is to be included in the corporation's proxy statement for an annual meeting of stockholders shall be deemed to comply with the requirements of this Section 1.11. A stockholder shall not have complied with this Section 1.11(b) if the stockholder (or beneficial owner, if any, on whose behalf the nomination is made) solicits or does not solicit, as the case may be, proxies in support of such stockholder's proposal in contravention of the representations with respect thereto required by this Section 1.11.

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        (c)   The chairman of any meeting shall have the power and duty to determine whether business was properly brought before the meeting in accordance with the provisions of this Section 1.11 (including whether the stockholder or beneficial owner, if any, on whose behalf the proposal is made solicited (or is part of a group that solicited) or did not so solicit, as the case may be, proxies in support of such stockholder's proposal in compliance with the representation with respect thereto required by this Section 1.11), and if the chairman should determine that business was not properly brought before the meeting in accordance with the provisions of this Section 1.11, the chairman shall so declare to the meeting and such business shall not be brought before the meeting.

        (d)   Notwithstanding the foregoing provisions of this Section 1.11, if the stockholder (or a qualified representative of the stockholder) does not appear at the annual meeting of stockholders of the corporation to present business, such business shall not be considered, notwithstanding that proxies in respect of such vote may have been received by the corporation. For purposes of this Section 1.11, to be considered a qualified representative of the stockholder, a person must be authorized by a written instrument executed by such stockholder or an electronic transmission delivered by such stockholder to act for such stockholder as a proxy at the meeting of stockholders and such person must produce such written instrument or electronic transmission, or a reliable reproduction of the written instrument or electronic transmission, at the meeting of stockholders.

        (e)   For purposes of this Section 1.11, "public disclosure" shall include disclosure in a press release reported by the Dow Jones New Service, Associated Press or comparable national news service or in a document publicly filed by the corporation with the Securities and Exchange Commission pursuant to Section 13, 14 or 15(d) of the Exchange Act.

        1.12    Conduct of Meetings.   

        (a)   Meetings of stockholders shall be presided over by the Chairman of the Board, if any, or in the Chairman's absence by the Vice Chairman of the Board, if any, or in the Vice Chairman's absence by the Chief Executive Officer, or in the Chief Executive Officer's absence, by the President, or in the President's absence by a Vice President, or in the absence of all of the foregoing persons by a chairman designated by the Board of Directors, or in the absence of such designation by a chairman chosen by vote of the stockholders at the meeting. The Secretary shall act as secretary of the meeting, but in the Secretary's absence the chairman of the meeting may appoint any person to act as secretary of the meeting.

        (b)   The Board of Directors may adopt by resolution such rules, regulations and procedures for the conduct of any meeting of stockholders of the corporation as it shall deem appropriate including such guidelines and procedures as it may deem appropriate regarding the participation by means of remote communication of stockholders and proxy holders not physically present at a meeting. Except to the extent inconsistent with such rules, regulations and procedures as adopted by the Board of Directors, the chairman of any meeting of stockholders shall have the right and authority to prescribe such rules, regulations and procedures and to do all such acts as, in the judgment of such chairman, are appropriate for the proper conduct of the meeting. Such rules, regulations or procedures, whether adopted by the Board of Directors or prescribed by the chairman of the meeting, may include, without limitation, the following: (i) the establishment of an agenda or order of business for the meeting; (ii) rules and procedures for maintaining order at the meeting and the safety of those present; (iii) limitations on attendance at or participation in the meeting to stockholders of record of the corporation, their duly authorized and constituted proxies or such other persons as shall be determined; (iv) restrictions on entry to the meeting after the time fixed for the commencement thereof; and (v) limitations on the time allotted to questions or comments by participants. Unless and to the extent determined by the Board of Directors or the chairman of the meeting, meetings of stockholders shall not be required to be held in accordance with the rules of parliamentary procedure.

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        (c)   The chairman of the meeting shall announce at the meeting when the polls for each matter to be voted upon at the meeting will be opened and closed. If no announcement is made, the polls shall be deemed to have opened when the meeting is convened and closed upon the final adjournment of the meeting. After the polls close, no ballots, proxies or votes or any revocations or changes thereto may be accepted.

        (d)   In advance of any meeting of stockholders, the Board of Directors, the Chairman of the Board, the Chief Executive Officer or the President shall appoint one or more inspectors of election to act at the meeting and make a written report thereof. One or more other persons may be designated as alternate inspectors to replace any inspector who fails to act. If no inspector or alternate is present, ready and willing to act at a meeting of stockholders, the chairman of the meeting shall appoint one or more inspectors to act at the meeting. Unless otherwise required by law, inspectors may be officers, employees or agents of the corporation. Each inspector, before entering upon the discharge of such inspector's duties, shall take and sign an oath faithfully to execute the duties of inspector with strict impartiality and according to the best of such inspector's ability. The inspector shall have the duties prescribed by law and shall take charge of the polls and, when the vote in completed, shall make a certificate of the result of the vote taken and of such other facts as may be required by law.

    1.13    Consent in Lieu of a Meeting.    Unless otherwise restricted by the Certificate of Incorporation, any action required or permitted by the Delaware General Corporation Law to be taken at any annual or special meeting of the stockholders of the Corporation, may be taken without a meeting, without prior notice and without a vote, if a consent or consents in writing or by electronic transmission, setting forth the action so taken, shall be signed or delivered by the holders of outstanding stock having not less than the minimum number of votes that would be necessary to take such action at a meeting at which all shares entitled to vote thereon were present and voted consent.

Prompt notice of the taking of the corporate action without a meeting by less than unanimous written consent shall be given to those stockholders who have not consented to the action taken.

ARTICLE II.

DIRECTORS

        2.1    General Powers.    The business and affairs of the corporation shall be managed by or under the direction of a Board of Directors, who may exercise all of the powers of the corporation except as otherwise provided by law or the Certificate of Incorporation.

        2.2    Number, Election and Qualification.    Subject to the rights of holders of any series of preferred stock to elect directors, the number of directors of the Corporation shall be established by the Board of Directors. Election of directors need not be by written ballot. Directors need not be stockholders of the corporation.

        2.3    Classes of Directors.    Subject to the rights of holders of any series of preferred stock to elect directors, the Board of Directors shall consist of one class.

        2.4    Terms of Office.    Subject to the rights of holders of any series of preferred stock to elect directors, each director shall serve for a term ending on the date of the first annual meeting following the annual meeting at which such director was elected; provided that the term of each director shall continue until the election and qualification of a successor and be subject to such director's earlier death, resignation or removal.

        2.5    Quorum.    The greater of (a) a majority of the directors at any time in office and (b) one-third of the number of directors fixed by the Board of Directors shall constitute a quorum. If at any meeting of the Board of Directors there shall be less than such a quorum, a majority of the directors present may adjourn the meeting from time to time without further notice other than announcement at the meeting, until a quorum shall be present.

        2.6    Action at Meeting.    Every act or decision done or made by a majority of the directors present at a meeting duly held at which a quorum is present shall be regarded as the act of the Board of Directors unless a greater number is required by law or by the Certificate of Incorporation.

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        2.7    Removal.    Subject to the rights of holder of any series of preferred stock, directors of the corporation may be removed only for cause and only by the affirmative vote of the holders of at least 75% of the votes that all the stockholders would be entitled to cast in any annual election of directors or class of directors.

        2.8    Vacancies.    Subject to the rights of holder of any series of preferred stock, any vacancy or newly-created directorships on the Board of Directors, however occurring, shall be filled only by vote of a majority of the directors then in office, although less than a quorum, or by a sole remaining director and shall not be filled by the stockholders. A director elected to fill a vacancy shall hold office until the next election of the class for which such director shall have been chosen, subject to the election and qualification of a successor or until such director's earlier death, resignation or removal.

        2.9    Resignation.    Any director may resign by delivering a resignation in writing or by electronic transmission to the corporation at its principal office or to the Chairman of the Board, the Chief Executive Officer, the President or the Secretary. Such resignation shall be effective upon receipt unless it is specified to be effective at some later time or upon the happening of some later event.

        2.10    Regular Meetings.    Regular meetings of the Board of Directors may be held without notice at such time and place as shall be determined from time to time by the Board of Directors; provided that any director who is absent when such a determination is made shall be given notice of the determination. A regular meeting of the Board of Directors may be held without notice immediately after and at the same place as the annual meeting of stockholders.

        2.11    Special Meetings.    Special meetings of the Board of Directors may be held at any time and place designated in a call by the Chairman of the Board, the Chief Executive Officer, the President, two or more directors, or by one director in the event that there is only a single director in office.

        2.12    Notice of Special Meetings.    Notice of any special meeting of directors shall be given to each director by the Secretary or by the officer or one of the directors calling the meeting. Notice shall be duly given to each director (a) in person or by telephone at least 24 hours in advance of the meeting, (b) by sending written notice via reputable overnight courier, telecopy or electronic mail, or delivering written notice by hand, to such director's last known business, home or electronic mail address at least 48 hours in advance of the meeting, or (c) by sending written notice via first-class mail to such director's last known business or home address at least 72 hours in advance of the meeting. A notice or waiver of notice of a meeting of the Board of Directors need not specify the purposes of the meeting.

        2.13    Meetings by Conference Communications Equipment.    Directors may participate in meetings of the Board of Directors or any committee thereof by means of conference telephone or other communications equipment by means of which all persons participating in the meeting can hear each other, and participation by such means shall constitute presence in person at such meeting.

        2.14    Action by Consent.    Any action required or permitted to be taken at any meeting of the Board of Directors or of any committee thereof may be taken without a meeting, if all members of the Board of Directors or committee, as the case may be, consent to the action in writing or by electronic transmission, and the written consents or electronic transmissions are filed with the minutes of proceedings of the Board of Directors or committee.

        2.15    Committees.    The Board of Directors may designate one or more committees, each committee to consist of one or more of the directors of the corporation. The Board of Directors may designate one or more directors as alternate members of any committee, who may replace any absent or disqualified member at any meeting of the committee. In the absence or disqualification of a member of a committee, the member or members of the committee present at any meeting and not disqualified from voting, whether or not such member or members constitute a quorum, may unanimously appoint another member of the Board of Directors to act at the meeting in the place of any such absent or disqualified member. Any such committee, to the extent provided in the resolution of the Board of Directors and subject to the provisions of law, shall have and may exercise all the powers and authority of the Board of Directors in the management of the business and affairs of the corporation and may authorize the seal of the corporation to be affixed to all papers that may require it. Each such committee shall keep minutes and make such reports as the Board of Directors may from time to time request. Except as the Board of Directors may otherwise determine, any committee may make rules for the conduct of its business, but unless otherwise provided by the directors or in such rules, its business shall be conducted as nearly as possible in the same manner as is provided in these By-laws for the Board of Directors. Except as otherwise provided in the Certificate of Incorporation, these By-laws, or the resolution of the Board of Directors designating the committee, a committee may create one or more subcommittees, each subcommittee to consist of one or more members of the committee, and delegate to a subcommittee any or all of the powers and authority of the committee.

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        2.16    Compensation of Directors.    Directors may be paid such compensation for their services and such reimbursement for expenses of attendance at meetings as the Board of Directors may from time to time determine. No such payment shall preclude any director from serving the corporation or any of its parent or subsidiary entities in any other capacity and receiving compensation for such service.

ARTICLE III.

OFFICERS

        3.1    Titles.    The officers of the corporation shall consist of a Chief Executive Officer, a President, a Secretary, a Treasurer and such other officers with such other titles as the Board of Directors shall determine, including a Chairman of the Board, a Vice Chairman of the Board, and one or more Vice Presidents, Assistant Treasurers, and Assistant Secretaries. The Board of Directors may appoint such other officers as it may deem appropriate.

        3.2    Election.    The Chief Executive Officer, President, Treasurer and Secretary shall be elected annually by the Board of Directors at its first meeting following the annual meeting of stockholders. Other officers may be appointed by the Board of Directors at such meeting or at any other meeting.

        3.3    Qualification.    No officer need be a stockholder. Any two or more offices may be held by the same person.

        3.4    Tenure.    Except as otherwise provided by law, by the Certificate of Incorporation or by these By-laws, each officer shall hold office until such officer's successor is elected and qualified, unless a different term is specified in the resolution electing or appointing such officer, or until such officer's earlier death, resignation or removal.

        3.5    Resignation and Removal.    Any officer may resign by delivering a written resignation to the corporation at its principal office or to the Chief Executive Officer, the President or the Secretary. Such resignation shall be effective upon receipt unless it is specified to be effective at some later time or upon the happening of some later event. Any officer may be removed at any time, with or without cause, by vote of a majority of the directors then in office. Except as the Board of Directors may otherwise determine, no officer who resigns or is removed shall have any right to any compensation as an officer for any period following such officer's resignation or removal, or any right to damages on account of such removal, whether such officer's compensation be by the month or by the year or otherwise, unless such compensation is expressly provided for in a duly authorized written agreement with the corporation.

        3.6    Vacancies.    The Board of Directors may fill any vacancy occurring in any office for any reason and may, in its discretion, leave unfilled for such period as it may determine any offices other than those of Chief Executive Officer, President, Treasurer and Secretary. Each such successor shall hold office for the unexpired term of such officer's predecessor and until a successor is elected and qualified, or until such officer's earlier death, resignation or removal.

        3.7    Chairman of the Board.    The Board of Directors may appoint from its members a Chairman of the Board, who need not be an employee or officer of the corporation. If the Board of Directors appoints a Chairman of the Board, such Chairman shall perform such duties and possess such powers as are assigned by the Board of Directors and, if the Chairman of the Board is also designated as the corporation's Chief Executive Officer, shall have the powers and duties of the Chief Executive Officer prescribed in Section 3.8 of these By-laws. Unless otherwise provided by the Board of Directors, the Chairman of the Board shall preside at all meetings of the Board of Directors and stockholders.

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        3.8    President; Chief Executive Officer.    Unless the Board of Directors has designated the Chairman of the Board or another person as the corporation's Chief Executive Officer, the President shall be the Chief Executive Officer of the corporation. The Chief Executive Officer shall have general charge and supervision of the business of the Corporation subject to the direction of the Board of Directors. The President shall perform such other duties and shall have such other powers as the Board of Directors or the Chief Executive Officer (if the President is not the Chief Executive Officer) may from time to time prescribe. In the event of the absence, inability or refusal to act of the Chief Executive Officer or the President (if the President is not the Chief Executive Officer), the Vice President (or if there shall be more than one, the Vice Presidents in the order determined by the Board of Directors) shall perform the duties of the Chief Executive Officer and when so performing such duties shall have all the powers of and be subject to all the restrictions upon the Chief Executive Officer.

        3.9    Vice Presidents.    Any Vice President shall perform such duties and possess such powers as the Board of Directors or the Chief Executive Officer may from time to time prescribe. The Board of Directors may assign to any Vice President the title of Executive Vice President, Senior Vice President or any other title selected by the Board of Directors.

        3.10    Secretary and Assistant Secretaries.    The Secretary shall perform such duties and shall have such powers as the Board of Directors or the Chief Executive Officer may from time to time prescribe. In addition, the Secretary shall perform such duties and have such powers as are incident to the office of the secretary, including the duty and power to give notices of all meetings of stockholders and special meetings of the Board of Directors, to attend all meetings of stockholders and the Board of Directors and keep a record of the proceedings, to maintain a stock ledger and prepare lists of stockholders and their addresses as required, to be custodian of corporate records and the corporate seal and to affix and attest to the same on documents. Any Assistant Secretary shall perform such duties and possess such powers as the Board of Directors, the Chief Executive Officer or the Secretary may from time to time prescribe. In the event of the absence, inability or refusal to act of the Secretary, the Assistant Secretary (or if there shall be more than one, the Assistant Secretaries in the order determined by the Board of Directors) shall perform the duties and exercise the powers of the Secretary. In the absence of the Secretary or any Assistant Secretary at any meeting of stockholders or directors, the chairman of the meeting shall designate a temporary secretary to keep a record of the meeting.

        3.11    Treasurer and Assistant Treasurers.    The Treasurer shall perform such duties and shall have such powers as may from time to time be assigned by the Board of Directors or the Chief Executive Officer. In addition, the Treasurer shall perform such duties and have such powers as are incident to the office of treasurer, including the duty and power to keep and be responsible for all funds and securities of the corporation, to deposit funds of the corporation in depositories selected in accordance with these By-laws, to disburse such funds as ordered by the Board of Directors, to make proper accounts of such funds, and to render as required by the Board of Directors statements of all such transactions and of the financial condition of the corporation. The Assistant Treasurers shall perform such duties and possess such powers as the Board of Directors, the Chief Executive Officer or the Treasurer may from time to time prescribe. In the event of the absence, inability or refusal to act of the Treasurer, the Assistant Treasurer (or if there shall be more than one, the Assistant Treasurers in the order determined by the Board of Directors) shall perform the duties and exercise the powers of the Treasurer.

        3.12    Salaries.    Officers of the corporation shall be entitled to such salaries, compensation or reimbursement as shall be fixed or allowed from time to time by the Board of Directors.

ARTICLE IV.

CAPITAL STOCK

          4.1. Issuance of Stock. Subject to the provisions of the Certificate of Incorporation, the whole or any part of any unissued balance of the authorized capital stock of the corporation or the whole or any part of any shares of the authorized capital stock of the corporation held in the corporation’s treasury may be issued, sold, transferred or otherwise disposed of by vote of the Board of Directors in such manner, for such lawful consideration and on such terms as the Board of Directors may determine.

          4.2. Stock Certificates; Uncertificated Shares. The shares of the corporation shall be represented by certificates, provided that the Board of Directors may provide by resolution or resolutions that some or all of any or all classes or series of its stock shall be uncertificated shares. Every holder of stock of the corporation represented by certificates shall be entitled to have a certificate, in such form as may be prescribed by law and by the Board of Directors, representing the number of shares held by such holder registered in certificate form. Each such certificate shall be signed in a manner that complies with Section 158 of the General Corporation Law of the State of Delaware.

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              Each certificate for shares of stock that are subject to any restriction on transfer pursuant to the Certificate of Incorporation, these By-laws, applicable securities laws or any agreement among any number of stockholders or among such holders and the corporation shall have conspicuously noted on the face or back of the certificate either the full text of the restriction or a statement of the existence of such restriction.  

              If the corporation shall be authorized to issue more than one class of stock or more than one series of any class, the powers, designations, preferences and relative participating, optional or other special rights of each class of stock or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights shall be set forth in full or summarized on the face or back of each certificate representing shares of such class or series of stock, provided that in lieu of the foregoing requirements there may be set forth on the face or back of each certificate representing shares of such class or series of stock a statement that the corporation will furnish without charge to each stockholder who so requests a copy of the full text of the powers, designations, preferences and relative, participating, optional or other special rights of each class of stock or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights.

              Within a reasonable time after the issuance or transfer of uncertificated stock, the corporation shall send to the registered owner thereof a written notice containing the information required to be set forth or stated on certificates pursuant to Sections 151, 202(a) or 218(a) of the General Corporation Law of the State of Delaware or, with respect to Section 151 of General Corporation Law of the State of Delaware, a statement that the corporation will furnish without charge to each stockholder who so requests the powers, designations, preferences and relative participating, optional or other special rights of each class of stock or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights.

              4.3. Transfers. Shares of stock of the corporation shall be transferable in the manner prescribed by law and in these By-laws. Transfers of shares of stock of the corporation shall be made only on the books of the corporation or by transfer agents designated to transfer shares of stock of the corporation. Subject to applicable law, shares of stock represented by certificates shall be transferred only on the books of the corporation by the surrender to the corporation or its transfer agent of the certificate representing such shares properly endorsed or accompanied by a written assignment or power of attorney properly executed, and with such proof of authority or the authenticity of signature as the corporation or its transfer agent may reasonably require. Except as may be otherwise required by law, by the Certificate of Incorporation or by these By-laws, the corporation shall be entitled to treat the record holder of stock as shown on its books as the owner of such stock for all purposes, including the payment of dividends and the right to vote with respect to such stock, regardless of any transfer, pledge or other disposition of such stock until the shares have been transferred on the books of the corporation in accordance with the requirements of these By-laws.

              4.4. Lost, Stolen or Destroyed Certificates. The corporation may issue a new certificate of stock in place of any previously issued certificate alleged to have been lost, stolen or destroyed, upon such terms and conditions as the Board of Directors may prescribe, including the presentation of reasonable evidence of such loss, theft or destruction and the giving of such indemnity and posting of such bond as the Board of Directors may require for the protection of the corporation or any transfer agent or registrar.

              4.5. Record Date. The Board of Directors may fix in advance a date as a record date for the determination of the stockholders entitled to notice of or to vote at any meeting of stockholders, or entitled to receive payment of any dividend or other distribution or allotment of any rights in respect of any change, conversion or exchange of stock, or for the purpose of any other lawful action. Such record date shall not precede the date on which the resolution fixing the record date is adopted, and such record date shall not be more than 60 nor less than 10 days before the date of such meeting, nor more than 60 days prior to any other action to which such record date relates.

              If no record date is fixed, the record date for determining stockholders entitled to notice of or to vote at a meeting of stockholders shall be at the close of business on the day before the day on which notice is given, or, if notice is waived, at the close of business on the day before the day on which the meeting is held. If no record date is fixed, the record date for determining stockholders for any other purpose shall be at the close of business on the day on which the Board of Directors adopts the resolution relating to such purpose.

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              A determination of stockholders of record entitled to notice of or to vote at a meeting of stockholders shall apply to any adjournment of the meeting; provided, however, that the Board of Directors may fix a new record date for the adjourned meeting.

              4.6. Regulations. The issue, transfer, conversion and registration of shares of stock of the corporation shall be governed by such other regulations as the Board of Directors may establish.

ARTICLE V.

GENERAL PROVISIONS

        5.1    Fiscal Year.    Except as from time to time otherwise designated by the Board of Directors, the fiscal year of the corporation shall begin on the first day of January of each year and end on the last day of December in each year.

        5.2    Corporate Seal.    The corporate seal shall be in such form as shall be approved by the Board of Directors.

        5.3    Waiver of Notice.    Whenever notice is required to be given by law, by the Certificate of Incorporation or by these By-laws, a written waiver signed by the person entitled to notice, or a waiver by electronic transmission by the person entitled to notice, whether before, at or after the time stated in such notice, shall be deemed equivalent to notice. Attendance of a person at a meeting shall constitute a waiver of notice of such meeting, except when the person attends a meeting for the express purpose of objecting at the beginning of the meeting, to the transaction of any business because the meeting is not lawfully called or convened.

        5.4    Voting of Securities.    Except as the Board of Directors may otherwise designate, the Chief Executive Officer, the President or the Treasurer may waive notice of, and act as, or appoint any person or persons to act as, proxy or attorney-in-fact for this corporation (with or without power of substitution) at any meeting of stockholders or security holders of any other entity, the securities of which may be held by this corporation.

        5.5    Evidence of Authority.    A certificate by the Secretary, or an Assistant Secretary, or a temporary Secretary, as to any action taken by the stockholders, directors, a committee or any officer or representative of the corporation shall as to all persons who rely on the certificate in good faith be conclusive evidence of such action.

        5.6    Certificate of Incorporation.    All references in these By-laws to the Certificate of Incorporation shall be deemed to refer to the Certificate of Incorporation of the corporation, as amended and in effect from time to time.

        5.7    Severability.    Any determination that any provision of these By-laws is for any reason inapplicable, illegal or ineffective shall not affect or invalidate any other provision of these By-laws.

        5.8    Pronouns.    All pronouns used in these By-laws shall be deemed to refer to the masculine, feminine or neuter, singular or plural, as the identity of the person or persons may require.

ARTICLE VI.

AMENDMENTS

        These By-laws may be altered, amended or repealed, in whole or in part, or new By-laws may be adopted by the Board of Directors or by the stockholders as provided in the Certificate of Incorporation.

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EX-5.1

Exhibit 5.1

Sullivan & Worcester LLP

One Post Office Square

Boston, MA 02109

February 3, 2010

American DG Energy Inc.

45 First Avenue

Waltham, MA 02451

Re: Registration Statement on Form S-3

File No. 333-163972

Ladies and Gentlemen:

The following opinion is being furnished to you in connection with the registration under the Securities Act of 1933, as amended (the “Securities Act”), by American DG Energy Inc., a Delaware corporation (the “Company”), of shares of its Common Stock (the “Registered Shares”) consisting of the following: 3,548,405 outstanding shares of common stock; 5,321,431 shares issuable upon conversion of outstanding convertible debentures; and 62,000 shares issuable upon exercise of warrants. The Registered Shares are being registered for resale pursuant to the above-described registration statement (the “Registration Statement”) being filed with the Securities and Exchange Commission (the “Commission”) pursuant to the Securities Act.

We have acted as counsel to the Company in connection with the Registration Statement, and we have examined originals or copies, certified or otherwise identified to our satisfaction, of the Registration Statement and such other documents as we have considered necessary in order to furnish the opinion hereinafter set forth.

Based on and subject to the foregoing, we are of the opinion that the outstanding shares of Common Stock being registered are, and the shares of Common Stock issuable upon conversion or exercise of convertible debt or warrants will be, upon the valid conversion or exercise thereof, duly authorized, validly issued, fully paid and nonassessable under the applicable provisions of Delaware law.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement.  In giving such consent, we do not thereby admit that we come within the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission promulgated thereunder.

 Very truly yours,

SULLIVAN AND WORCESTER LLP

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EX-10.1

Exhibit 10.1

AMERICAN DG ENERGY INC.

Audit Committee Charter

(as amended October 13, 2009)

Purpose

The purpose of the Audit Committee is to assist the Board of Directors in overseeing the Company’s accounting and financial reporting processes and the audits of the Company’s financial statements.

Structure and Membership

Number.  Except as otherwise permitted by the applicable Nasdaq rules, the Audit Committee shall consist of at least three members of the Board of Directors.

Independence.  Except as otherwise permitted by the applicable Nasdaq rules, each member of the Audit Committee shall be independent as defined by Nasdaq rules, meet the criteria for independence set forth in Rule 10A-3(b)(l) under the Securities Exchange Act (subject to the exemptions provided in Rule 10A-3(c) under such Act), and not have participated in the preparation of the financial statements of the Company or any current subsidiary of the Company at any time during the past three years.

Financial Literacy.  Each member of the Audit Committee must be able to read and understand fundamental financial statements, including the Company’s balance sheet, income statement, and cash flow statement, at the time of his or her appointment to the Audit Committee. In addition, at least one member must have past employment experience in finance or accounting, requisite professional certification in accounting, or any other comparable experience or background which results in the individual’s financial sophistication, including being or having been a chief executive officer, chief financial officer or other senior officer with financial oversight responsibilities. Unless otherwise determined by the Board of Directors (in which case disclosure of such determination shall be made in the Company’s annual report filed with the Securities and Exchange Commission), at least one member of the Audit Committee shall be an “audit committee financial expert” (as defined by applicable Securities and Exchange Commission rules).

Chair.  Unless the Board of Directors elects a Chair of the Audit Committee, the Audit Committee shall elect a Chair by majority vote.

Compensation.  The compensation of Audit Committee members shall be as determined by the Board of Directors. No member of the Audit Committee may receive, directly or indirectly, any consulting, advisory or other compensatory fee from the Company or any of its subsidiaries, other than fees paid in his or her capacity as a member of the Board of Directors or a committee of the Board.

Selection and Removal.  Members of the Audit Committee shall be appointed by the Board of Directors. The Board of Directors may remove members of the Audit Committee from such committee, with or without cause.

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Authority and Responsibilities

General

The Audit Committee shall discharge its responsibilities, and shall assess the information provided by the Company’s management and the independent auditor, in accordance with its business judgment. Management is responsible for the preparation, presentation, and integrity of the Company’s financial statements and for the appropriateness of the accounting principles and reporting policies that are used by the Company. The independent auditors are responsible for auditing the Company’s financial statements and for reviewing the Company’s unaudited interim financial statements. The authority and responsibilities set forth in this Charter do not reflect or create any duty or obligation of the Audit Committee to plan or conduct any audit, to determine or certify that the Company’s financial statements are complete, accurate, fairly presented, or in accordance with generally accepted accounting principles or applicable law, or to guarantee the independent auditor’s report.

Oversight of Independent Auditors

Selection.  The Audit Committee shall be solely and directly responsible for appointing, evaluating, retaining and, when necessary, terminating the engagement of the independent auditor. The Audit Committee may, in its discretion, seek stockholder ratification of the independent auditor it appoints.

Independence.  The Audit Committee shall take, or recommend that the full Board of Directors take, appropriate action to oversee the independence of the independent auditor. In connection with this responsibility, the Audit Committee shall obtain and review a formal written statement from the independent auditor describing all relationships between the auditor and the Company, including the disclosures required by Independence Standards Board Standard No. 1. The Audit Committee shall actively engage in dialogue with the auditor concerning any disclosed relationships or services that might impact the objectivity and independence of the auditor.

Compensation.  The Audit Committee shall have sole and direct responsibility for setting the compensation of the independent auditor. The Audit Committee is empowered, without further action by the Board of Directors, to cause the Company to pay the compensation of the independent auditor established by the Audit Committee.

Preapproval of Services.  The Audit Committee shall preapprove all audit services to be provided to the Company, whether provided by the principal auditor or other firms, and all other services (review, attest and non-audit) to be provided to the Company by the independent auditor; provided, however, that de minimis non-audit services may instead be approved in accordance with applicable Securities and Exchange Commission rules.

Oversight.  The independent auditor shall report directly to the Audit Committee, and the Audit Committee shall have sole and direct responsibility for overseeing the work of the independent auditor, including resolution of disagreements between Company management and the independent auditor regarding financial reporting. In connection with its oversight role, the Audit Committee shall, from time to time as appropriate, receive and consider the reports required to be made by the independent auditor regarding:

· critical accounting policies and practices;

· alternative treatments within generally accepted accounting principles for policies and practices related to material items that have been discussed with Company management, including ramifications of the use of such alternative disclosures and treatments, and the treatment preferred by the independent auditor; and

· other material written communications between the independent auditor and Company management.

Audited Financial Statements

Review and Discussion.  The Audit Committee shall review and discuss with the Company’s management and independent auditor the Company’s audited financial statements, including the matters about which Statement on Auditing Standards No. 61 (Codification of Statements on Auditing Standards, AU §380) requires discussion.

Recommendation to Board Regarding Financial Statements.  The Audit Committee shall consider whether it will recommend to the Board of Directors that the Company’s audited financial statements be included in the Company’s Annual Report on Form 10-K.

Audit Committee Report.  The Audit Committee shall prepare an annual committee report for inclusion where necessary in the proxy statement of the Company relating to its annual meeting of security holders.

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Review of Other Financial Disclosures

Independent Auditor Review of Interim Financial Statements.  The Audit Committee shall direct the independent auditor to use its best efforts to perform all reviews of interim financial information prior to disclosure by the Company of such information and to discuss promptly with the Audit Committee and the Chief Financial Officer any matters identified in connection with the auditor’s review of interim financial information which are required to be discussed by applicable auditing standards. The Audit Committee shall direct management to advise the Audit Committee in the event that the Company proposes to disclose interim financial information prior to completion of the independent auditor’s review of interim financial information.

Controls and Procedures

Oversight.  The Audit Committee shall coordinate the Board of Directors’ oversight of the Company’s internal control over financial reporting, disclosure controls and procedures and code of conduct. The Audit Committee shall receive and review the reports of the CEO and CFO required by Rule 13a-14 of the Securities Exchange Act.

Procedures for Complaints.  The Audit Committee shall establish procedures for (a) the receipt, retention and treatment of complaints received by the Company regarding accounting, internal accounting controls or auditing matters and (b) the confidential, anonymous submission by employees of the Company of concerns regarding questionable accounting or auditing matters.

Related-Party Transactions.  The Audit Committee shall review all “related party transactions” (defined as transactions required to be disclosed pursuant to Item 404 of Regulation S-K promulgated by the Securities and Exchange Commission) on an ongoing basis, and all such transactions must be approved by the Audit Committee.

Additional Powers.  The Audit Committee shall have such other duties as may be delegated from time to time by the Board of Directors.

Procedures and Administration

Meetings.  The Audit Committee shall meet as often as it deems necessary in order to perform its responsibilities, but at least once each calendar quarter. The Audit Committee may also act by unanimous written consent in lieu of a meeting. The Audit Committee shall periodically meet separately with (a) the independent auditor and (b) Company management. The Audit Committee shall keep such records of its meetings as it shall deem appropriate.

Subcommittees.  The Audit Committee may form and delegate authority to one or more subcommittees (including a subcommittee consisting of a single member), as it deems appropriate from time to time under the circumstances. Any decision of a subcommittee to preapprove audit, review, attest or non-audit services shall be presented to the full Audit Committee at its next scheduled meeting.

Reports to Board.  The Audit Committee shall report regularly to the Board of Directors.

Charter.  At least annually, the Audit Committee shall review and reassess the adequacy of this Charter and recommend any proposed changes to the Board of Directors for approval.

Independent Advisors.  The Audit Committee is authorized, without further action by the Board of Directors, to engage such independent legal, accounting and other advisors as it deems necessary or appropriate to carry out its responsibilities. Such independent advisors may be the regular advisors to the Company. The Audit Committee is empowered, without further action by the Board of Directors, to cause the Company to pay the compensation of such advisors as established by the Audit Committee.

Investigations.  The Audit Committee shall have the authority to conduct or authorize investigations into any matters within the scope of its responsibilities as it shall deem appropriate, including the authority to request any officer, employee or advisor of the Company to meet with the Audit Committee or any advisors engaged by the Audit Committee.

Funding.  The Audit Committee is empowered, without further action by the Board of Directors, to cause the Company to pay the ordinary administrative expenses of the Audit Committee that are necessary or appropriate in carrying out its duties.

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EX-10.3

Exhibit 10.3

AMERICAN DG ENERGY INC.

Nominating and Governance Committee Charter

The Nominating and Governance Committee (the “Committee”) of the Board of Directors (the “Board”) of American DG Energy Inc. (the “Company”) shall consist of a minimum of three (3) directors.  In the event one or more vacancies on the Committee temporarily reduce the number of members to two (2), actions taken by the two members of the Committee will be deemed authorized actions of the Committee.  Members of the Committee shall be appointed by the Board and shall serve until the meeting of the Board occurring immediately after the next following annual meeting of the stockholders, and until their successor are duly elected and qualified, unless they are earlier removed by the Board acting in its discretion.

Purpose

The purpose of the Committee shall be:

(1) to assist the Board by recommending the composition of the Board and in identifying individuals qualified to become Board members, consistent with criteria approved by the Board;

(2) to advise the Board with respect to functions and structures of committees;

(3) to develop, recommend to the Board and implement corporate governance principles applicable to the Company;

(4) to assist the Board in providing for planned succession of senior management positions;

(5) to develop and monitor a process to assess the effectiveness of the Board and to lead the Board in its annual review of the Board’s performance; and

(6) to develop and propose for consideration by the Board compensation policies for the Company’s non-employee directors that enable the Company to retain highly qualified individuals for such positions.

In furtherance of this purpose, the Committee shall have the following authority and responsibilities:

1. To lead the search for individuals qualified to become members of the Board, consistent with criteria approved by the Board and to recommend to the Board nominees to be presented for election as directors by shareholders at each annual meeting of shareholders.  The Committee shall select individuals as director nominees who have the highest personal and professional integrity, who shall have demonstrated exceptional ability and judgment and who shall be most effective, in conjunction with the other nominees to and members of the Board, in collectively serving the long-term interests of the shareholders.

2. To review the Board’s committee structure and to recommend to the Board for its approval directors to serve as members of each committee.  The Committee shall review and recommend committee slates annually and shall recommend additional committee members to fill vacancies as needed.

3. To develop and recommend to the Board for its approval corporate governance guidelines.  The Committee shall review the guidelines on an annual basis, or more frequently if appropriate, and recommend changes as necessary.

4. To oversee the development and implementation of senior executive succession plans.

5. To develop and recommend to the Board for its approval an annual self-evaluation of the Board and its committees.  The Committee shall oversee the annual self-evaluation.  In addition, the Committee shall consider and evaluate other methods of assessing the effectiveness of the Board.

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6. To review annually the Company’s compensation package for non-employee directors to ensure that compensation to such persons is competitive and appropriate, and to recommend changes, when appropriate, to the Board for approval.

Subcommittees

The Committee shall have the authority to delegate any of its responsibilities to subcommittees as the Committee may deem appropriate in its sole discretion.

Committee Membership Qualifications

All of the members of the Committee shall meet the independence requirements of the corporate governance rules of such national securities exchange on which the shares of Common Stock of the Company are listed.

Miscellaneous

The Committee shall have the authority to retain (or terminate) any search firm engaged to assist in identifying director candidates, and to retain outside counsel and any other advisors as the Committee may deem appropriate in its sole discretion.  The Committee shall have sole authority to approve related fees and retention terms.

The Committee shall report its actions and recommendations to the Board after each Committee meeting and shall conduct and present to the Board an annual performance evaluation of the Committee.  The Committee shall review at least annually the adequacy of this charter and recommend any proposed changes to the Board for approval.

Adopted:                      August 31, 2009

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EX-10.12

Exhibit 10.12

AMERICAN DISTRIBUTED GENERATION INC.

SUBSCRIPTION AGREEMENT

Dear Sir or Madam:

1.             Subscription.  The undersigned, intending to be legally bound, irrevocably subscribes for and agrees to purchase the aggregate number of shares of the common stock (“Common Stock”), par value $.001 per share (each a “Share” and collectively, the “Shares”), and warrants to purchase shares of Common Stock  (each a “Warrant” and collectively, the “Warrants”) of American Distributed Generation Inc., a Delaware corporation  (the “Company”), indicated on the signature page hereof, on the terms and conditions described herein and in the Confidential Private Placement Memorandum dated July 25, 2003 (which, together with all exhibits, attachments, amendments and supplements thereto, is referred to as the “Memorandum”). The undersigned has also completed the Accredited Investor Questionnaire attached to this Agreement.

The undersigned herewith delivers to the Company the consideration (“Purchase Price”) required to purchase the Shares and the Warrants subscribed for hereunder by wire transfer funds payable to: American Distributed Generation Inc., 45 First Avenue, Waltham, MA 02451. The minimum investment is for $50,000 unless otherwise determined in the discretion of the Company. The Shares and the Warrants will be issued in accordance with the terms and conditions set forth in the Memorandum. Capitalized terms not otherwise defined in this Agreement have the meanings specified in the Memorandum.

2.             Investor Representations, Warranties and Covenants. The undersigned hereby acknowledges, represents and warrants to, and agrees with the Company as follows:

(a)           The undersigned is acquiring the Shares and the Warrants for the undersigned’s own account as principal, for investment purposes only, and not with a view to, or for, resale or distribution of all or any part of the Shares and the Warrants, and no other person has a direct or indirect beneficial interest in such Shares or Warrants;

(b)           The undersigned acknowledges its understanding that the offering and sale of the Shares and the Warrants is intended to be exempt from registration under the Securities Act of 1933, as amended (the “Securities Act”), by virtue of Section 4(2) of the Securities Act and Rule 505 of Regulation D (“Regulation D”) promulgated thereunder and Section 4(6) of the Securities Act, and, in furtherance thereof, the undersigned represents and warrants to and agrees with the Company that the undersigned has the financial ability to bear the economic risk of the undersigned’s investment, has adequate means for providing for the undersigned’s current needs and contingencies and has no need for liquidity with respect to the undersigned’s investment in the Shares and the Warrants.

(c)           The undersigned is an “accredited investor” as defined in Rule 501(a) of Regulation D under the Securities Act. The undersigned hereby certifies that the information set forth in the attached Accredited Investor Questionnaire is accurate and complete as of the date of this Agreement.

(d)           The undersigned:

(1)           has been furnished with a copy of the Memorandum and any other documents which have been made available upon request and the undersigned has carefully read the Memorandum and understands and has evaluated the risks of a purchase of the Shares and the Warrants, including the risks set forth under “Risk Factors” in the Memorandum; and has relied solely on the information contained in the Memorandum, and any supplemental written information furnished pursuant to Subsection (ii) below;

(2)           has been given the opportunity to ask questions of and receive answers from the Company concerning the terms and conditions of the Offering of the Shares and the Warrants, and has been given the opportunity to obtain additional information necessary to satisfy the undersigned as to the accuracy of the information contained in the Memorandum to the extent that the Company possesses such information or can acquire it without unreasonable effort or expense and has not been furnished with any other offering literature except as referred to in the Memorandum;

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(3)           has not relied on any oral representation, warranty or information in connection with the Offering of the Shares and the Warrants by the Company, or any officer, employee, agent or affiliate of the Company;

(4)           has determined that the Shares and the Warrants are a suitable investment for the undersigned and that at this time the undersigned can bear a complete loss of the undersigned’s investment therein;

(5)           has such knowledge and experience in financial and business matters that the undersigned is capable of evaluating the merits and risks of the undersigned’s investment in the Shares and the Warrants;

(e)           If the undersigned is a corporation, limited liability company, partnership, trust, qualified  plan or other entity, it is authorized and qualified to become a holder of the Shares and the Warrants, and the person signing this Subscription Agreement on behalf of such entity has been duly authorized to do so;

(f)           Any information which the undersigned has heretofore furnished and herewith furnishes to the Company with respect to the undersigned’s financial position and business experience is correct and complete as of the date of this Agreement and if there should be any material change in such information prior to issuance to the undersigned of the Shares and the Warrants, the undersigned will immediately furnish such revised or corrected information to the Company;

(g)           The foregoing acknowledgments, representations, warranties and agreements shall survive  the closing at which the Shares and the Warrants are issued;

(h)           The undersigned acknowledges that the undersigned has not purchased the Shares or the Warrants as a result of any general solicitation or general advertising; and

(i)           The undersigned’s overall commitment to investments which are not readily marketable is not disproportionate to the undersigned’s net worth, and the undersigned’s prospective investment in the Company and will not cause such overall commitment to become excessive.

3.            Investor Awareness.  The undersigned acknowledges that:

(a)           No federal or state agency has passed upon the Shares or the Warrants or made any finding or determination as to the fairness of this investment;

(b)           There is no established market for the Shares or the Warrants and no assurance has been given that any public market for them will develop;

(c)           Neither the Shares nor the Warrants may be sold, pledged or otherwise transferred, except as may be permitted under the Securities Act and applicable state securities laws pursuant to registration or exemption therefrom; and accordingly, the undersigned may be required to bear the financial risks of an investment in the Shares and the Warrants for an indefinite period of time;

(d)           The undersigned consents to (i) the placing of a legend substantially in the form set forth below on the certificates representing the Shares (or upon any certificates representing shares of Common Stock issued upon exercise of the Warrants) stating that the securities have not been registered and setting forth the restriction on transfer contemplated hereby, and (ii) the placing of a stop transfer order on the books of the Company and with any transfer agents against the Shares.

“The shares represented by this certificate have not been registered under the Securities Act of 1933, as amended.  These shares have been acquired for investment and not with a view to distribution or resale and may not be sold, mortgaged, pledged, hypothecated or otherwise transferred without an effective registration statement for such sales under the Securities Act of 1933, or an opinion of counsel for the corporation that registration is not required under such Act.

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The shares represented by this certificate are also subject to the provisions of a certain Investor Rights Agreement dated July 25, 2003 and may not be transferred except in accordance with the provisions of that agreement.”

4.             Miscellaneous.

(a)           Indemnity. The undersigned agrees to indemnify and hold harmless the Company, its affiliates, directors, officers, employees, agents and controlling persons (the Company and each such person being an “Indemnified Party”), from and against any and all losses, claims, damages, liabilities and expenses whatsoever (including, but not limited to, any and all expenses whatsoever reasonably incurred investigating, preparing or defending against any litigation commenced or threatened or any claim whatsoever), joint or several, as incurred, to which such Indemnified Party may become subject under any applicable United States federal or state law or the laws of any other domestic or foreign jurisdiction, or otherwise, and related to or arising out of or based upon any false representation, warranty or acknowledgment, or breach or failure by the undersigned to comply with any covenant or agreement made by the undersigned herein or in any other document furnished by the undersigned to any of the foregoing in connection with this transaction.

(b)           Modification.  Except as otherwise provided herein, neither this Agreement nor any provisions hereof shall be modified, discharged or terminated except by an instrument in writing signed by the party against whom any waiver, change, discharge or termination is sought.

(c)           Binding Effect.  Except as otherwise provided herein, this Agreement shall be binding upon and inure to the benefit of the parties and their heirs, executors, administrators, successors, legal representatives and assigns. If the undersigned is more than one person, the obligation of the undersigned shall be joint and several and the agreements, covenants, representations, warranties and acknowledgments herein contained shall be deemed to be made by and be binding upon each such person and his heirs, executors, administrators and successors.

(d)           Entire Agreement.  This instrument contains the entire agreement of the parties and there are no representations, warranties, acknowledgments, covenants or other agreements except as stated or referred to herein.

(e)           Assignability.  This Agreement is not transferable or assignable by the undersigned.

(f)           Governing Law and Forum.  Notwithstanding the place where this Agreement may be executed by any of the parties hereto, all the terms and provisions hereof shall be construed in accordance with and governed by the laws of the Commonwealth of Massachusetts, without giving effect to its conflict of law principles. Any dispute which may arise out of or in connection with this Agreement shall be adjudicated before a court located in Middlesex County, Massachusetts and the parties hereby submit to the exclusive jurisdiction of the courts of the Commonwealth of Massachusetts located in Boston, Massachusetts and of the federal courts in Boston, Massachusetts with respect to any action or legal proceeding commenced by any party, and irrevocably waive any objection they now or hereafter may have respecting the venue of any such action or proceeding brought in such a court or respecting the fact that such court is an inconvenient forum, relating to or arising out of this Agreement or any acts or omissions relating to the sale of the Shares or the Warrants, and the undersigned consents to the service of process in any such action or legal proceeding by means of registered or certified mail, return receipt requested, in care of the address set forth below or such other address as the undersigned shall furnish in writing to the Company. In the event any such action is brought, whether at law or in equity, then the prevailing party shall be paid its reasonable attorney's fees, expenses and disbursements arising out of such action. The undersigned hereby waives trial by jury in any action or proceeding involving, directly or indirectly, any matter (whether sounding in tort, contract, fraud or otherwise) in any way arising out of or in connection with this Agreement or the Holder’s purchase of the Shares and the Warrants.

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ALL SUBSCRIBERS MUST COMPLETE THIS PAGE

IN WITNESS WHEREOF, the undersigned has executed this Subscription Agreement on the day of

___________________, 2003.

Number of Shares and Warrants Subscribed for: ____________

Purchase Price:   $______________

Manner in which Title is to be held (Please Check One):

1. ¨ Individual

2. ¨ Joint Tenants with Right of Survivorship

3. ¨ Community Property

4. ¨ Tenants in Common

5. ¨ Corporation / Limited Liability Company / Partnership

6. ¨ IRA

7. ¨ Trust / Estate / Pension or Profit Sharing Plan

Date Opened: __________

8. ¨ As a Custodian for __________________ Under the Uniform Gift to Minors Act
of the State of __________________

9. ¨ Married with Separate Property

10. ¨ Keogh

11. ¨ Tenants by the Entirety

IF MORE THAN ONE SUBSCRIBER, EACH SUBSCRIBER MUST SIGN

INDIVIDUAL SUBSCRIBERS MUST COMPLETE PAGES A4 AND A5

SUBSCRIBERS WHICH ARE ENTITIES MUST COMPLETE PAGES A4 AND A6

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EXECUTION BY NATURAL PERSONS

___________________________________

Exact Name in Which Title is to be Held

Name of Purchaser (Print)	Name of Additional Purchaser
Address	Address
City, State and Zip Code	City, State and Zip Code
Social Security Number	Social Security Number
Signature of Purchaser	Signature of Additional Purchaser

ACCEPTED this  day of _______________, 2003 on behalf of the Company.

By:

Name:

Title:

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EXECUTION BY SUBSCRIBER THAT IS AN ENTITY

(Corporation, Limited Liability Company, Partnership, Trust, Etc.)

________________________________________________________

Name of Entity (Please Print)

Date of Incorporation or Organization:  _________________________________________

State of Principal Offices: _____________________________________________________

Federal Taxpayer Identification Number: ________________________________________

By: ____________________________
Title: ____________________________
Attest: _________________________	Address: _________________________
(If Entity is a Corporation)
	_________________________________
	_________________________________
	Taxpayer Identification Number

ACCEPTED this  day of _______________, 2003 on behalf of the Company.

By:	_______________________
Name:	_______________________
Title:	_______________________

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ACCREDITED INVESTOR QUESTIONNAIRE

Please check the box below that best characterizes the person or entity subscribing for the Shares and the Warrants under the terms of the foregoing Subscription Agreement.

¨ a natural person whose individual net worth, or joint net worth with that person’s spouse, at the time of his purchase exceeds US $1,000,000.

¨ a natural person who had an individual income in excess of $200,000 in each of the two most recent years or joint income with that person’s spouse in excess of $300,000 in each of those years and has a reasonable expectation of reaching the same income level in the current year.

¨ an organization described in Section 501(c)(3) of the Internal Revenue Code, a corporation, a Massachusetts or similar business trust or a partnership, in each case, not formed for the purpose of this investment, with total assets in excess of US $5,000,000.

¨ a director, executive officer, or general partner of the issuer of the securities being offered or sold, or any director, executive officer, or general partner of a general partner of that issuer.

¨ a trust with total assets in excess of US $5,000,000, not formed for the specific purpose of acquiring the securities offered, whose purchase is directed by a sophisticated person as described in Rule 506(b)(2)(ii) of the Securities Act of 1933.

¨ an entity in which all of the equity owners are accredited investors.

¨ a private business development company as defined in Section 202(a)(22) of the Investment Advisers Act of 1940.

¨ a Small Business Investment Company licensed by the U.S. Small Business Administration  under Section 301(c) or (d) of the Small Business Investment Act of 1958.

¨ an investment company registered under the Investment Company Act of 1940 or a business development company as defined in Section 2(a)(48) of that Act.

¨ a bank as defined in Section 3(a)(2) or a savings and loan association or other institution defined in Section 3(a)(5)(A) of the Securities Act of 1933 acting in either an individual or fiduciary capacity.

¨ an insurance company as defined in Section 2(13) of the Securities Act of 1933.

¨ an employee benefit plan within the meaning of Title I of the Employee Retirement Income Security Act of 1974 whose investment decision is made by a fiduciary which is either a bank, savings and loan association, insurance company, or registered investment advisor, or whose total assets exceed US $5,000,000, or, if a self-directed plan, a plan whose investment decisions are made solely by persons who are accredited investors.

¨ any broker or dealer registered pursuant to Section 15 of the Securities Exchange Act of 1934.

¨ any plan established and maintained by a state, its political subdivisions, or any agency or instrumentality of a state or its political subdivisions for the benefit of its employees, if such plan has total assets in excess of $5,000,000.

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EX-10.13

Exhibit 10.13

American DG Energy Inc.

RESTRICTED STOCK PURCHASE AGREEMENT

This Agreement is made as of the 20th day of February 2007 by and between American DG Energy Inc., a Delaware corporation having its principal place of business at 45 First Avenue, Waltham, Massachusetts 02451 (the “Company”), and Charles T. Maxwell, an individual having an address at 33 Oriole Avenue, Bronxville, NY 10708 (the “Purchaser”).

The Company desires to sell, and the Purchaser desires to purchase, 100,000 shares of the Common Stock of the Company (the “Shares”). The Shares are subject to repurchase by the Company if the Purchaser ceases to be an employee of, or consultant, or director to the Company or any parent, subsidiary or affiliate of the Company for any reason.

NOW THEREFORE, in consideration of the covenants and agreements set forth herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby mutually acknowledged, the parties hereto covenant and agree as follows:

1.           Definitions. For the purposes of this Agreement, the following terms shall have the following respective meanings.

“Act” shall mean the Securities Act of 1933, as amended from time to time, and the rules and regulations thereunder.

“Change in Control” shall mean (a) the acquisition in a transaction or series of transactions by any person (such term to include anyone deemed a person under Section 13(d)(3) under the Exchange Act), other than the Company or any of its subsidiaries, or any employee benefit plan or related trust of the Company or any of its subsidiaries, of beneficial ownership (within the meaning of Rule 13d-3 promulgated under the Exchange Act) of fifty percent (50%) or more of the combined voting power of the then outstanding voting securities of the Company entitled to vote generally in the election of directors; provided a Change in Control shall not occur solely as the result of an Initial Public Offering or (b) the sale or other disposition of all or substantially all of the assets of the Company in one transaction or series of related transactions.

“Common Stock” shall mean the shares of Common Stock, par value $.001 per share, of the Company.

“Company” shall have the meaning set forth in the preamble to this Agreement.

“Exchange Act” shall mean the Securities Exchange Act of 1934, as amended from time to time, and the rules and regulations thereunder.

“Purchaser” shall have the meaning set forth in the preamble to this Agreement.

“Initial Public Offering” shall mean the consummation of the first fully underwritten, firm commitment public offering pursuant to an effective registration statement under the Act, other than on Forms S-4 or S-8 or their then equivalents, covering the offer and sale by the Company of its equity securities, the registration of the Company pursuant to Section 12(b) or (g) of the Exchange Act or such other event as a result of or following which the Shares shall be listed on Nasdaq, OTC or on any securities exchange on which the Shares are listed for trading.

“Permitted Transferee” shall mean any of the following to whom the Purchaser may subsequently transfer Shares hereunder: the Purchaser’s spouse, children (natural or adopted), stepchildren, or a trust for the sole benefit of any of such persons of which the Purchaser is the settlor or any other affiliate of the Purchaser.

“Repurchase” shall have the meaning set forth in Section 6 of this Agreement.

“Restricted Shares” shall initially mean all of the Shares that are not Vested Shares.

“Shares” shall have the meaning set forth in the preamble to this Agreement.

“Termination Event” shall mean the termination of the Purchaser’s status as an employee of, or consultant, or director to the Company or any parent, subsidiary or affiliate of the Company for any reason.

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“Vested Shares” shall mean 25%of the Shares one year after an Initial Public Offering and then 25% of the Shares on each subsequent anniversary of the Initial Public Offering. All of the Shares shall become Vested Shares upon a Change in Control prior to a termination event.

2.           Purchase and Sale of the Shares. The Company hereby sells the Shares to the Purchaser, and the Purchaser hereby purchases the Shares from the Company, for a purchase price of $.001 per share or an aggregate purchase price of One Hundred Dollars ($100.00) (the “Purchase Price”). The Company hereby acknowledges receipt of the Purchase Price from the Purchaser. The parties agree to execute and deliver such further documents as may be necessary to give effect to the purchase and sale of the Shares.

3.           Representations by the Company. The Company hereby represents and warrants to the Purchaser that (a) it has the corporate power and authority to sell the Shares to the Purchaser, and (b) it has good and marketable title to the Shares free and clear of all security interests, liens, encumbrances or other claims. Except as set forth in the preceding sentence, the Company makes no representation or warranty to the Purchaser with respect to either the Shares or the Company.

4.           Representations by the Purchaser. The Purchaser hereby represents and warrants to the Company as follows:

(a)           The Purchaser is acquiring the Shares for his or her own account as principal, for investment purposes only, and not with a view to, or for, resale or distribution of all or any part of the Shares, and no other person has a direct or indirect beneficial interest in such Shares.

(b)           The Purchaser acknowledges his or her understanding that the sale of the Shares is intended to be exempt from registration under the Act, and, in furtherance thereof, the Purchaser represents and warrants to and agrees with the Company that the Purchaser has the financial ability to bear the economic risk of his or her investment in the Shares, has adequate means for providing for his or her current needs and contingencies and has no need for liquidity with respect to his or her investment in the Shares.

(c)           The Purchaser has determined the Shares are a suitable investment for the Purchaser and that at this time he or she can bear a complete loss of his or her investment in the Shares.

5.           Acknowledgments by the Purchaser. The Purchaser acknowledges that:

(a)           No federal or state agency has passed upon the Shares or made any finding or determination as to the fairness of this investment.

(b)           There is no established market for the Shares and no assurance has been given that any public market for them will develop.

(c)           The Shares may not be sold, pledged or otherwise transferred, except as may be permitted under the Act and applicable state securities laws pursuant to registration or exemption therefrom; and accordingly, the Purchaser may be required to bear the financial risks of an investment in the Shares for an indefinite period of time.

6.           Repurchase of Restricted Shares.

(a)           Repurchase. Upon the occurrence of a Termination Event, the Company shall have the right and option to repurchase (the “Repurchase”) all or any portion of the Restricted Shares (that is, Shares that are not then Vested Shares) held by the Purchaser or any Permitted Transferee as of the date of such Termination Event at the purchase price of $.001 per share.

(b)           Closing Procedure. The Company shall effect the Repurchase (if so elected) by delivering or mailing to the Purchaser (and/or, if applicable, any Permitted Transferees) written notice within three (3) months after the Termination Event, specifying a date within such three-month period in which the Repurchase shall be effected. Upon such notification, the Purchaser and any Permitted Transferees shall promptly surrender to the Company any certificates representing the Restricted Shares being purchased, together with a duly executed stock power for the transfer of such Restricted Shares to the Company.  Upon the Company’s receipt of the certificates from the Purchaser or any Permitted Transferees, the Company shall deliver to the Purchaser or any Permitted Transferee a check for the purchase price of the Restricted Shares being purchased. The Repurchase right specified herein shall survive and remain in effect as to Restricted Shares following and notwithstanding any public offering by the Company and certificates representing such Restricted Shares shall bear legends to such effect.

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(c)           Remedy. Without limitation of any other provision of this Agreement or other rights, in the event that the Purchaser, any Permitted Transferee or any other person or entity is required to sell the Restricted Shares pursuant to the provisions of this Section 6 and in the further event that he, she or it refuses or for any reason fails to deliver to the Company the certificate or certificates evidencing such Restricted Shares together with a related stock power, such designated purchaser may deposit the purchase price for such Restricted Shares with a bank designated by the Company, or with the Company’s independent public accounting firm, as agent or trustee, or in escrow, for the Purchaser, any Permitted Transferee or other person or entity, to be held by such bank or accounting firm for the benefit of and for delivery to the Purchaser, any Permitted Transferee or other person or entity.  Upon any such deposit and upon notice to the Purchaser or Permitted Transferee who was required to sell the Restricted Shares to be sold pursuant to the provisions of this Section 6, such Restricted Shares shall at such time be deemed to have been sold, assigned, transferred and conveyed to such purchaser, the holder thereof shall have no further rights thereto (other than the right to withdraw the payment thereof held in escrow, if applicable), and the Company shall record such transfer in its stock transfer book or in any appropriate manner.

7.             Restrictions on Transfer of Shares. None of the Shares shall be sold, assigned, transferred, pledged, hypothecated, given away or in any other manner disposed of or encumbered, whether voluntarily or by operation of law, unless such transfer is in compliance with all applicable federal and state securities laws and such disposition is in accordance with the terms and conditions of this Section 7. In connection with any transfer of Shares, the Company may require the transferor to provide at the transferor’s own expense an opinion of counsel to the transferor, satisfactory to the Company that such transfer is in compliance with all foreign, federal and state securities laws. Any attempted disposition of Shares not in accordance with the terms and conditions of this Section 7 shall be null and void, and the Company shall not reflect on its records any change in record ownership of any Shares as a result of any such disposition, shall otherwise refuse to recognize any such disposition and shall not in any way give effect to any such disposition of any Shares. Subject to the foregoing general provisions, the Purchaser may sell, assign, transfer or give away any or all of the Shares only to Permitted Transferees; provided, however, that such Permitted Transferee(s) shall, as a condition to any such transfer, agree to be subject to the provisions of this Agreement (including, without limitation, the provisions of Section 6 and this Section 7) and shall have delivered a written acknowledgment to that effect to the Company.

8.             Legend. Each certificate(s) representing the Shares shall carry substantially the following legend:

“The transferability of this certificate and the shares of stock represented hereby are subject to the restrictions, terms and conditions (including repurchase and restrictions against transfers) contained in a certain Restricted Stock Purchase Agreement between the Company and the holder of this certificate (a copy of which is available at the offices of the Company for examination).

The securities represented hereby have not been registered under the Securities Act of 1933, as amended (the “Act”), or any state securities or “blue sky” laws and may not be offered, sold, transferred, hypothecated or otherwise assigned except (1) pursuant to a registration statement with respect to such securities which is effective under the Act; or (2) pursuant to an available exemption from registration under the Act relating to the disposition of securities; and (3) in accordance with applicable state securities and “blue sky” laws.”

9.            Miscellaneous Provisions.

(a)           Record Owner; Dividends. The Purchaser and any Permitted Transferees, during the duration of this Agreement, shall be considered the record owners of and shall be entitled to vote the Shares. The Purchaser and any Permitted Transferees shall be entitled to receive all dividends and any other distributions declared on the Shares; provided, however, that the Company is under no duty to declare any such dividends or to make any such distribution.

(b)           Equitable Relief. The parties hereto agree and declare that legal remedies are inadequate to enforce the provisions of this Agreement and that equitable relief, including specific performance and injunctive relief, may be used to enforce the provisions of this Agreement.

(c)           Change and Modifications. This Agreement may not be orally changed, modified or terminated, nor shall any oral waiver of any of its terms be effective. This Agreement may be changed, modified or terminated only by an agreement in writing signed by the Company and the Purchaser.

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(d)           Choice of Law. Notwithstanding the place where this Agreement may be executed by any of the parties hereto, all the terms and provisions hereof shall be construed in accordance with and governed by the laws of the Commonwealth of Massachusetts, excluding any conflicts or choice of law rule or principle that might otherwise refer construction or interpretation of this agreement to the substantive law of another jurisdiction. Any dispute which may arise out of or in connection with this Agreement shall be adjudicated before a court located in Boston, Massachusetts and the parties hereby submit to the exclusive jurisdiction of the courts of the Commonwealth of Massachusetts located in Boston, Massachusetts and of the federal courts in Boston, Massachusetts with respect to any action or legal proceeding commenced by any party, and irrevocably waive any objection they now or hereafter may have respecting the venue of any such action or proceeding brought in such a court or respecting the fact that such court is an inconvenient forum, relating to or arising out of this Agreement or any acts or omissions relating to the sale and purchase of the Shares, and each of the Company and the Purchaser (including any Permitted Transferees) consents to the service of process in any such action or legal proceeding by means of registered or certified mail, return receipt requested, or by means of a recognized overnight air courier service in care of the address set forth below or such other address as each party shall furnish in writing to the other. In the event any such action is brought, whether at law or in equity, then the prevailing party shall be paid his, her or its reasonable attorneys’ fees, expenses and disbursements arising out of such action. The parties hereby waive trial by jury in any action or proceeding involving, directly or indirectly, any matter (whether sounding in tort, contract, fraud or otherwise) in any way arising out of or in connection with this Agreement or the purchase of the Shares.

(e)           Headings. The headings are intended only for convenience in finding the subject matter and do not constitute part of the text of this Agreement and shall not be considered in the interpretation of this Agreement.

(f)            Saving Clause. If any provision(s) of this Agreement shall be determined to be illegal or unenforceable, such determination shall in no manner affect the legality or enforceability of any other provision hereof.

(g)           Notices. All notices, requests, consents and other communications shall be in writing and be deemed given when delivered personally, by facsimile transmission or by a recognized overnight courier service or when received if mailed by first class registered or certified mail, postage prepaid.  Notices to the Company or the Purchaser shall be sent to the addresses first set forth above, or to such other address or addresses as may have been furnished by such party in writing to the other. Notices to any holder of the Shares other than the Purchaser shall be addressed to the address furnished by such holder to the Company.

(h)           Benefit and Binding Effect. This Agreement shall be binding upon and shall inure to the benefit of the parties hereto, their respective successors, assigns, and legal representatives. Without limitation of the foregoing, upon any stock-for-stock merger in which the Company is not the surviving entity, shares of the Company’s successor issued in respect of the Shares shall remain subject to terms, conditions and restrictions set forth herein. The Company has the right to assign this Agreement, and such assignee shall become entitled to all the rights of the Company hereunder to the extent of such assignment.

(i)            Employment or Consulting. This Agreement does not confer upon the Purchaser any rights with respect to continuation of his or her employment or consulting relationship with the Company, nor shall it interfere with any right of the Company to terminate such employment or consulting relationship at any time.

(j)            Counterparts. For the convenience of the parties and to facilitate execution, this Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which shall constitute one and the same document.

IN WITNESS WHEREOF, the Company and the Purchaser have executed this Restricted Stock Purchase Agreement as of the date first above written.

AMERICAN DG ENERGY INC.

By:
Name:   John N. Hatsopoulos	Name: Charles T. Maxwell
Title:     CEO

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EX-10.15

Exhibit 10.15

AMERICAN DG ENERGY INC.

COMMON STOCK PURCHASE AGREEMENT

TO:         American DG Energy Inc.

45 First Avenue

Waltham, Massachusetts 02451

Ladies and Gentlemen:

The undersigned (the “Investor”) desires to purchase from American DG Energy Inc., a Delaware corporation (the “Company”), _______ shares of its Common Stock, par value $.001 per share (the “Common Stock”). The purchase price for each share of Common Stock is $0.70.

1.            Subscription

a.            Subject to the terms and conditions of this Agreement (this “Agreement”), the Investor agrees to subscribe for and purchase from the Company and tenders this subscription for _______ shares of Common Stock (the “Shares”) together with payment of the subscription price for the Shares in the amount of $________. The subscription price is referred to in this Agreement as the “Funds”.

b.            Tender of the Funds shall be made by delivery of a personal or bank check payable to the Company or by wire transfer to the Company’s designated bank account, together with executed copies of this Agreement. The Investor should deliver the executed subscription documents and payment for the Shares to the Company, at 45 First Avenue, Waltham, MA  02451 Attention: Anthony S. Loumidis, Chief Financial Officer, Phone (781) 622-1117.

2.            Acceptance of Agreement

It is understood and agreed that this Subscription is made subject to the following terms and conditions:

The Company shall have the right to accept or reject this Subscription, in whole or in part, for any reason, the ineligibility of a subscriber under applicable state or foreign securities laws, for any other reason or for no reason. If this Subscription is rejected, the Funds previously delivered to the Company will be returned to the Investor.

b.            Two complete copies of this Agreement will be executed by the Investor. If this Subscription is accepted, one copy of this Common Stock Purchase Agreement as accepted by the Company shall be delivered to the Investor.

c.            If this Subscription is accepted in part and rejected in part, the Investor will be so notified, at which time the excess Funds previously delivered to the Company will be returned to the Investor.

           3.             Representations and Warranties of the Investor

In order to induce the Company to accept this Agreement, the Investor hereby represents and warrants to the Company as follows:

a.            THE INVESTOR HAS READ CAREFULLY AND UNDERSTANDS THIS AGREEMENT AND HAS CONSULTED THE INVESTOR'S OWN ATTORNEY, ACCOUNTANT OR INVESTMENT ADVISER WITH RESPECT TO THE INVESTMENT CONTEMPLATED HEREBY AND ITS SUITABILITY FOR THE INVESTOR.  THE INVESTOR HAS HAD AN OPPORTUNITY TO ASK QUESTIONS OF AND RECEIVED ANSWERS FROM THE COMPANY, OR A PERSON OR PERSONS ACTING ON THE COMPANY'S BEHALF, CONCERNING THE TERMS AND CONDITIONS OF THIS INVESTMENT AND THE BUSINESS OF THE COMPANY, AND HAS RECEIVED AND REVIEWED ALL ADDITIONAL DOCUMENTATION REGARDING THE BUSINESS AND OPERATIONS OF THE COMPANY THAT HE OR SHE HAS REASONABLY REQUESTED.

b.            The Investor (i) has no need for liquidity in the investment in the Shares, (ii) is able to bear the substantial economic risks of an investment in the Shares for an indefinite period, and (iii) at the present time, could afford the complete loss of such investment in the Shares.

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c.            The address set forth at the end of this Agreement is the Investor's true and correct residence, and the Investor has no present intention of changing such residence to any other state or jurisdiction.

d.            The Investor confirms that all documents, records and books pertaining to the investment in the Company reasonably requested by the Investor have been made available to the Investor. The undersigned has relied only on such documents and that no written or oral representation or information inconsistent with such information has been made or furnished to the Investor in connection with the Shares and if so made, has not been relied upon.

e.            The Investor understands that the Shares have not been registered under the Securities Act, nor pursuant to the provisions of the securities laws or other laws of any other applicable jurisdictions, in reliance on exemptions for private offerings contained in the Securities Act and in the laws of such jurisdictions. The Investor represents to the Company that he is an “accredited investor”, as such term is defined in Rule 501(a) of Regulation D under the Securities Act of 1933, as amended. The Investor is fully aware that the Shares to which he or she is subscribing are to be sold in reliance upon such exemptions based upon his or her representations, warranties and agreements set forth in this Agreement. The Investor is fully aware that he or she must bear the economic risk of his or her investment in the Company for an indefinite period of time because the Shares have not been registered under the Securities Act, and, therefore, cannot be offered or sold unless they are subsequently registered under the Securities Act or an exemption from such registration is available. The Investor further understands that the Company has no intention and is under no obligation to register its Shares under the Securities Act or to comply with the requirements for any exemption that might otherwise be available, or to supply the Investor with any information necessary to enable the Investor to make routine sales of the Shares under Rule 144under the Securities Act (which it understands is not now, and will not likely be, available) or any rule of the Securities and Exchange Commission or any successor thereto.

f.             The Investor understands that the certificate(s) representing the Shares will bear the following legend restricting its transfer and that a notation restricting such transfer will be made on the stock transfer books of the Company:

“THE SHARES OF STOCK REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT") OR THE APPLICABLE SECURITIES LAWS OF ANY STATE OR OTHER JURISDICTION. THESE SHARES HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO THEIR DISTRIBUTION OR RESALE.  SUCH SHARES MAY NOT BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT FOR SUCH SHARES UNDER THE ACT, OR AN OPINION OF COUNSEL SATISFACTORY IN FORM AND SUBSTANCE TO THE COMPANY TO THE EFFECT THAT SUCH REGISTRATION IS NOT REQUIRED.”

g.            The Shares are being acquired solely for the Investor's own account, for investment and are not being purchased with a view to or for the resale or other distribution of the Shares; and the Investor has no present plans to enter into any contract, undertaking, agreement or arrangement relating to any resale or other distribution of the Shares.

h.            The Investor understands that this Subscription may be accepted or rejected in whole or in part in the sole and absolute discretion of the Company, and this Agreement, unless properly revoked before the completion of the sale of the Shares to the Investor, shall survive the Investor’s death, disability or insolvency, except that the Investor shall have no obligations in the event that this Subscription is rejected by the Company.

i.            The Investor understands that even if the Company becomes a "reporting company" under the Securities Exchange Act of 1934, as amended, the provisions of Rule 144 promulgated under the Securities Act permitting resales of the Shares will not be available for at least one (1) year, and there can be no assurance that the conditions necessary to permit routine sales of the Shares under Rule 144 will ever be satisfied, and, if Rule 144 should become available, routine sales made in reliance on its provisions could be made only in limited amounts and in accordance with the terms and conditions of the Rule.  The Investor further understands that in connection with sales of securities for which Rule 144 is not available, compliance with some other exemption from registration will be required.  The Investor understands that the Company is under no obligation to the undersigned to register the Shares or to comply with the conditions of Rule 144 or take any other action necessary in order to make available any exemption for the sale of the Shares without registration.

j.            The Investor has been advised to consult with the Investor’s own attorney regarding legal, tax, and other matters concerning an investment in the Company and has done so, to the extent the undersigned considers necessary.

k.            The Investor acknowledges and is aware of the following:

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(i)           that the Shares are a speculative investment and involve a high degree of risk of loss by the Investor of the Investor'sentire investment in the Company;

(ii)           that there is no guarantee that the Investor will realize any gain from his or her investment in the Company and that the Investor may lose his or her entire investment;

(iii)         that the Company hasno current plan or intention to issue dividends with respect to the Shares;

(iv)         that there has never been any representation, guarantee or warranty made to the Investor by any broker, the Company, its agents or employees or any other person, expressly or by implication, as to:

(A)          the approximate or exact length of time that the Investor will be required to remain as owner of the Shares; or

(B)          the past performance or experience on the part of the officers or directors of the Company, or of any other person, that will in any way indicate the predictable results of the ownership of the Shares or any such other securities, or of the overall business of the Company;

v)           that the Company may in the future issue additional shares of capital stock in the Company, and that the Investor's interest in the Company may thereby become diluted.

The Investor acknowledges that he or she understands the meaning and legal consequences of the representations, warranties and acknowledgments contained in this Agreement. The Investor confirms that such representations, warranties and acknowledgments are true and accurate as of the date of this Agreement and shall be true and accurate as of the date of delivery of the Funds to the Company and shall survive such delivery. If in any respect such representations and warranties shall not be true and accurate prior to acceptance of this Agreement pursuant to Section 2 of this Agreement, the Investor shall give written notice of such fact to the Company, specifying which representations and warranties are not true and accurate and the reasons therefor.

4.             Indemnification. The Investor acknowledges that he or she understands the meaning and legal consequences of the representations and warranties contained in Section 3 of this Agreement, and the Investoragrees to indemnify, defend and hold harmless the Company and each officer, director, representative and agent of the Company and any person or entity controlling the Company from and against any and all loss, cost, damage or liability (including reasonable attorneys' fees) due to or arising out of a breach of any representation or warranty of the Investor contained in this Agreement.

5.             No Waiver. Notwithstanding any of the representations, warranties, acknowledgments or agreements made in this Agreement bythe Investor, the Investor does not thereby or in any other manner waive any rights granted to the Investor under federal and state securities law.

6.             Transferability. The Investor agrees not to transfer or assign this Agreement, or any of the Investor's interest in this Agreement, and further agrees that any assignment or transfer of the Shares shall be made only in accordance with applicable securities laws and that an appropriate legend with respect thereto may be placed by the Company on any certificate evidencing such Shares.

7.             Revocation. The Investor agrees that he or she shall not cancel, terminate or revoke this Agreement.

8.             Termination of Agreement. If any representation or warranty of the Investor contained in Section 3 of this Agreement shall not be true prior to acceptance of this Agreement, and written notice of such fact has been given by the Investor to the Company, then and in any such event this Agreement shall be null and void and of no further force and effect, and no party shall have any rights against any other party under this Agreement or otherwise, and the Company shall promptly return to the Investor the Funds together with all agreements executed by the Investor.

9.             Dispute Resolution

a.            All disputes, claims, or controversies arising out of or relating to this Agreement or any other agreement executed and delivered pursuant to this Agreement or the negotiation, validity or performance hereof and thereof or the transactions contemplated hereby and thereby that are not resolved by mutual agreement shall be resolved solely and exclusively by binding arbitration to be conducted before the American Arbitration Association (“AAA”).  If AAA ceases operation, then the parties shall select a comparable organization that provides qualified arbitration services.  The arbitration shall be held in Boston, Massachusetts before a single arbitrator and shall be conducted in accordance with the rules and regulations promulgated by AAA unless specifically modified herein.

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b.           The parties covenant and agree that the arbitration hearing shall commence within ninety (90) days of the date on which a written demand for arbitration is filed by any party hereto.  In connection with the arbitration proceeding, the arbitrator shall have the power to order the production of documents by each party and any third-party witnesses.  In addition, each party may take up to three depositions as of right, and the arbitrator may in his or her discretion allow additional depositions upon good cause shown by the moving party.  However, the arbitrator shall not have the power to order the answering of interrogatories or the response to requests for admission.  In connection with any arbitration, each party shall provide to the other, no later than seven (7) business days before the date of the arbitration hearing, the identity of all persons that may testify at the arbitration and a copy of all documents that may be introduced at the arbitration hearing or considered or used by a party’s witness or expert. The arbitrator’s decision and award shall be made and delivered within three (3) months of the selection of the arbitrator. The arbitrator’s decision shall set forth a reasoned basis for any finding of liability or award of damages.  The arbitrator shall not have power to award damages in excess of actual compensatory damages and shall not multiply actual damages or award punitive damages or any other damages that are specifically excluded under this Agreement, and each party hereby irrevocably waives any claim to such damages.

c.           The parties covenant and agree that they will participate in the arbitration in good faith and that they will share equally its costs, except as otherwise provided herein.  The arbitrator may in his or her discretion assess costs and expenses (including the reasonable legal fees and expenses of the prevailing party whether claimant or respondent) against any party to a proceeding.  Any party failing or refusing to comply with an order of the arbitrators shall be liable for costs and expenses, including attorneys’ fees, incurred by the other party in enforcing the award. Nothing in this Section 9 shall prohibit any party from proceeding in court without prior arbitration for the limited purpose of seeking a temporary or permanent injunction to avoid immediate and irreparable harm.  The provisions of this Section 9 shall be enforceable in any court of competent jurisdiction.

d.             Unless otherwise ordered, the parties shall bear their own attorneys’ fees, costs and expenses in connection with the arbitration.  The parties will share equally in the fees and expenses charged by AAA.

e.             Each of the parties hereto irrevocably and unconditionally consents to the exclusive use of AAA to resolve all disputes, claims or controversies arising out of or relating to this Agreement or any other agreement executed and delivered pursuant to this Agreement or the negotiation, validity or performance hereof and thereof or the transactions contemplated hereby and thereby and further consents to the jurisdiction of the federal or state courts of the Commonwealth of Massachusetts for the purposes of enforcing the arbitration provisions of Section 9a of this Agreement.  Each party further irrevocably waives any objection to proceeding before AAA based upon lack of personal jurisdiction or to the laying of venue and further irrevocably and unconditionally waives and agrees not to make a claim in any court that arbitration before AAA has been brought in an inconvenient forum.  Each of the parties hereto hereby consents to service of process by registered mail at the address to which notices are to be given.  Each of the parties hereto agrees that its or his submission to jurisdiction and its or his consent to service of process by mail is made for the express benefit of the other parties hereto.

10.           Miscellaneous

a.             All notices or other communications given or made under this Agreement shall be in writing and shall be delivered or mailed by (a) registered or certified mail, return receipt requested, postage prepaid, or (b) overnight air courier, fees prepaid, to the Investor at his or her address set forth below and to the Company at its address set forth at the outset of this Agreement.

b.             Failure of the Company to exercise any right or remedy under this Agreement or any other agreement between the Company and the Investor, or delay by the Company in exercising the same, will not operate as a waiver of such right or remedy.  No waiver by the Company will be effective unless and until it is in writing and signed on behalf of the Company.

c.             Notwithstanding the place where this Agreement may be executed by any of the parties hereto, all the terms and provisions hereof shall be construed in accordance with and governed by the laws of the Commonwealth of Massachusetts, without giving effect to its conflict of law principles.

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d.            This Agreement is binding upon and inures to the benefit of the parties hereto and their respective heirs, successors and permitted assigns.  This Agreement cannot be assigned, amended or modified by the parties hereto, except by written agreement executed by the parties hereto.

e.            This Agreement may be executed in one or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

f.             If any provision of this Agreement shall for any reason be held invalid or unenforceable, such invalidity or unenforceability shall not affect any other provision hereof and this Agreement shall be construed as if such invalid or unenforceable provision had never been contained herein.

g.            This Agreement constitutes the entire agreement between the parties with respect to the subject matter of this Agreement and may be amended only bya writing executed by all parties.

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IN WITNESS WHEREOF, the undersigned has executed this Agreement on this ___ day of April, 2007.

Manner in which Title is to be held (Please Check One):

1. ¨ Individual

2. ¨ Joint Tenants With Right of Survivorship

3. ¨ Community Property

4. ¨ Tenants in Common

5. ¨ Married with Separate Property

EXECUTION BY NATURAL PERSONS

___________________________________________________________________________

Exact Name(s) in Which Title is to be Held

(If Joint Tenant or Tenants in Common, both persons must

sign and this page must contain all information for both persons).

___________________________________	___________________________________
Signature	Signature
___________________________________	__________________________________
Name (Please Print)	Name (Please Print)
__________________________________	__________________________________
Residence: Number and Street	Residence: Number and Street
___________________________________	___________________________________
City, State, Zip Code	City, State, Zip Code
___________________________________	___________________________________
Social Security Number	Social Security Number
___________________________________
Telephone Number

Accepted this ___ day of April 2007, on behalf of the Company.

AMERICAN DG ENERGY INC.
By:
Name:	Anthony S. Loumidis
Title:	Chief Financial Officer

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EXECUTION BY SUBSCRIBER THAT IS AN ENTITY

(Corporation, Limited Liability Company, Partnership, Trust, Etc.)

________________________________________________________

Name of Entity (Please Print)

Date of Incorporation or Organization:	____________________________________________________
State of Principal Offices:	____________________________________________________
Federal Taxpayer Identification Number:	____________________________________________________

	By:	_______________________________
	Title:	________________________
Attest: _________________________	Address:	________________________
(If Entity is a Corporation)
		_______________________________
		_______________________________
		_______________________________
		Taxpayer Identification Number

Accepted this ___ day of April 2007, on behalf of the Company.

AMERICAN DG ENERGY INC.
By:
Name:	Anthony S. Loumidis
Title:	Chief Financial Officer

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ACCREDITED INVESTOR QUESTIONNAIRE

Please check the box below that best characterizes the person or entity subscribing for the Shares under the terms of the foregoing Subscription Agreement.

¨ Any natural person whose individual net worth, or joint net worth with that person’s spouse, at the time of his purchase exceeds US $1,000,000;

¨ Any natural person who had an individual income in excess of $200,000 in each of the two most recent years or joint income with that person’s spouse in excess of $300,000 in each of those years and has a reasonable expectation of reaching the same income level in the current year;

¨ Any organization described in Section 501(c)(3) of the Internal Revenue Code, a corporation, a Massachusetts or similar business trust or a partnership, in each case, not formed for the purpose of this investment, with total assets in excess of US $5,000,000;

¨ Any director, executive officer, or general partner of the issuer of the securities being offered or sold, or any director, executive officer, or general partner of a general partner of that issuer;

¨ Any trust with total assets in excess of US $5,000,000, not formed for the specific purpose of acquiring the securities offered, whose purchase is directed by a sophisticated person as described in Rule 506(b)(2)(ii) of the Securities Act of 1933;

¨ Any entity in which all of the equity owners are accredited investors;

¨ Any private business development company as defined in Section 202(a)(22) of the Investment Advisers Act of 1940;

¨ Any Small Business Investment Company licensed by the U.S. Small Business Administration under Section 301(c) or (d) of the Small Business Investment Act of 1958;

¨ Any investment company registered under the Investment Company Act of 1940 or a business development company as defined in Section 2(a)(48) of that Act;

¨ Any bank as defined in Section 3(a)(2) or a savings and loan association or other institution defined in Section 3(a)(5)(A) of the Securities Act of 1933 acting in either an individual or fiduciary capacity;

¨ Any insurance company as defined in Section 2(13) of the Securities Act of 1933;

¨ Any employee benefit plan within the meaning of Title I of the Employee Retirement Income Security Act of 1974 whose investment decision is made by a fiduciary which is either a bank, savings and loan association, insurance company, or registered investment advisor, or whose total assets exceed US $5,000,000, or, if a self-directed plan, a plan whose investment decisions are made solely by persons who are accredited investors;

¨ Any broker or dealer registered pursuant to Section 15 of the Securities Exchange Act of 1934; or

¨ Any plan established and maintained by a state, its political subdivisions, or any agency or instrumentality of a state or its political subdivisions for the benefit of its employees, if such plan has total assets in excess of $5,000,000.

¨ None of the above.

Name of Subscriber:	__________________________________
Social Security Number:	__________________________________
Signature:	__________________________________

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EX-10.19

Exhibit 10.19

SUBSCRIPTION AGREEMENT

THIS SUBSCRIPTION AGREEMENT (this “Agreement”), is by and between American DG Energy Inc., a Delaware corporation (the “Company”), and the subscriber identified on the signature page below (the “Subscriber”).

The Company and the Subscriber hereby agree as follows:

1.           Purchase and Sale of Shares.

a)           Subject to the terms and conditions of this Agreement, at the First Closing (as defined herein), the Company shall sell and issue to the Subscriber, and the Subscriber shall purchase from the Company that number of shares of the Company’s Common Stock set forth on the signature page at the per share purchase price also specified therein.

b)           At the Second Closing (as defined herein), at the option of the Subscriber, the Company shall sell and issue to the Subscriber, and the Subscriber shall purchase from the Company, that number of shares of the Company’s Common Stock set forth on the signature page at the per share purchase price also specified therein. The shares sold at the First Closing and, if issued, the shares sold at the Second Closing are referred to herein as the “Shares”.

2.           Closings.  The Closings shall take place as follows:

a)           The first closing (the “First Closing”) of the sale and purchase of the Shares pursuant to this Agreement is taking place contemporaneously with the execution and delivery of this Agreement on the date hereof. At the First Closing, the Subscriber is wiring to an account specified by the Company the purchase price for the Shares being purchased at the First Closing. As soon as practical after the First Closing, the Company will cause its transfer agent to deliver to the Subscriber a certificate representing that number of Shares so purchased, which shall be registered in the name of the Purchaser or its nominee.

b)           The Subscriber shall indicate to the Company by written notice given no later than December 15th, 2009, whether or not it elects that the second closing under this Agreement (the “Second Closing”) shall occur. Such notice shall specify a closing date for the Second Closing no more than 3 business days after the delivery of such notice, or December 18th, 2009. At the Second Closing, the Subscriber will wire to an account specified by the Company the purchase price for the Shares being purchased at the Second Closing. As soon as practical after the Second Closing, the Company will cause its transfer agent to deliver to the Subscriber a certificate representing that number of Shares so purchased, which shall be registered in the name of the Purchaser or its nominee.

c)           The First Closing and the Second Closing, if any, shall be collectively referred to as the “Closings,” each may individually be referred to as a “Closing” and the date of each Closing shall be referred to as a “Closing Date.” All deliveries at each Closing shall take place by the electronic delivery, by fax or email, of all closing documents.

(d)           In the event that the Subscriber shall notify the Company that it elects that the Second Closing shall occur, the obligation of the Subscriber to consummate the Second Closing shall be subject to the satisfaction, prior to or at the Second Closing, of the following conditions:  (i) the representations and warranties of the Company contained in this Agreement shall be true and correct in all material respects on and as of the Second Closing Date as though such warranties and representations were made at and as of such date; (ii) the Company shall have performed and complied in all material respects with all agreements, covenants and conditions contained in this Agreement which are required to be performed or complied with by the Company prior to or at the Closing; and (iii) there shall be no effective injunction, writ, preliminary restraining order or any order of any nature issued by a court of competent jurisdiction directing that the transactions provided for herein or any of them not be consummated as herein provided.

(e)           In the event that the Subscriber shall notify the Company that it elects that the Second Closing shall occur, the obligation of the Company to consummate the Second Closing shall be subject to the satisfaction, prior to or at the Second Closing, of the following conditions:  (i)  the representations and warranties of the Subscriber contained in this Agreement shall be true on and as of the Second Closing Date in all material respects as though such warranties and representations were made at and as of such date; (ii) the Subscriber shall have performed and complied in all material respects with all agreements, covenants and conditions contained in this Agreement which are required to be performed or complied with by it prior to or at the Second Closing; and (iii) there shall be no effective injunction, writ, preliminary restraining order or any order of any nature issued by a court of competent jurisdiction directing that the transactions provided for herein or any of them not be consummated as herein provided.

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3.           Subscriber’s Representations and Warranties. The Subscriber hereby represents and warrants to and agrees with the Company that:

(a)         Information on Company.  The Subscriber has been furnished with or has had access at the EDGAR website of the U.S. Securities and Exchange Commission (the “SEC”) to the Company’s Form 10-K for the year ended December 31, 2008, and all filings subsequently made by the Company with the SEC (hereinafter referred to collectively as the “Reports”). In addition, the Subscriber has received in writing from the Company such other information concerning its operations, financial condition and other matters as the Subscriber has requested in writing and considered all factors the Subscriber deems material in deciding on the advisability of investing in the Shares.

(b)         Information on Subscriber.  The Subscriber was at the time it was offered the Shares, is on the date hereof and will be on the Closing Date an “accredited investor”, as such term is defined in Reg. D promulgated by the SEC under the Securities Act, is experienced in investments and business matters, has made investments of a speculative or high risk nature and has purchased securities of publicly-owned companies in private placements in the past and, together with its representatives and/or trustee, as applicable, has such knowledge and experience in financial, tax and other business matters as to enable the Subscriber to utilize the information made available by the Company to evaluate the merits and risks of and to make an informed investment decision with respect to the proposed purchase. The Subscriber has the authority and is duly and legally qualified to purchase and own the Shares. The Subscriber is able to bear the risk of such investment for an indefinite period and to afford a complete loss thereof. The information set forth on the signature page regarding the Subscriber is accurate. The Subscriber does not currently hold or beneficially own any shares of the Company’s Common Stock other than as set forth on the signature page. The Subscriber was not formed for the specific purpose of acquiring the Shares and is not a registered broker-dealer or an affiliate of a registered broker-dealer.

(c)         Purchase for Investment.  On the Closing Date, the Subscriber will purchase the Shares as principal for its own account for investment and not with a view to any sale of other transfer thereof in contravention of the Securities Act.

(d)         Compliance with the Securities Act.  The Subscriber understands and agrees that the Shares have not been registered under the Securities Act of 1933 (the “Securities Act”) or any applicable state securities laws by reason of their issuance in a transaction that does not require registration under the Securities Act (based in part on the accuracy of the representations and warranties of Subscriber contained herein), and that such Shares must be held indefinitely unless a subsequent disposition is registered under the Securities Act or any applicable state securities laws or is exempt from such registration.

(e)         Restrictive Legend. The Shares may bear a customary restrictive Securities Act legend in the form specified by the Company.

 (f)         Communication of Offer. The offer to sell the Shares was directly communicated to the Subscriber by the Company. At no time was the Subscriber presented with or solicited by any leaflet, newspaper or magazine article, radio or television advertisement, or any other form of general advertising or solicited or invited to attend a promotional meeting otherwise than in connection and concurrently with such communicated offer.

(g)         Organization; Authority; Enforceability.  The Subscriber, if an entity, is duly organized, validly existing and in good standing under the laws of the jurisdiction of its organization (if such “good standing” concept is recognized in such jurisdiction) with full right, corporate,  partnership or trust power and authority to enter into and to consummate the transactions contemplated by this Agreement. This Agreement and other agreements delivered together with this Agreement or in connection herewith have been duly authorized, executed and delivered by the Subscriber and are valid and binding agreements enforceable in accordance with their terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights generally and to general principles of equity; and Subscriber has full corporate, partnership, trust or similar power and authority necessary to enter into this Agreement and such other agreements and to perform its obligations hereunder and under all other agreements entered into by the Subscriber relating hereto.

(h)         Correctness of Representations. The Subscriber represents that the foregoing representations and warranties are true and correct as of the date hereof and, unless the Subscriber otherwise notifies the Company prior to the Closing, shall be true and correct as of the Closing Date.

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(i)           Survival. The foregoing representations and warranties shall survive the applicable Closing Date for three years.

(j)           Restriction on Short Sales. The Subscriber agrees that, to the extent required by law, it will not enter into or effect any short sale or other hedging transaction with respect to the Company’s Common Stock.

(k)          Disclosure. The Subscriber acknowledges and agrees that the Company does not make nor has made any representations or warranties with respect to the Shares or the transactions contemplated hereby other than those specifically set forth in Section 4 hereof.

4.           Company Representations and Warranties.  The Company represents and warrants to and agrees with the Subscriber that on the date hereof:

(a)          Due Incorporation. The Company is a corporation duly organized, validly existing and in good standing under the laws of the State of Delaware and has the requisite corporate power to own its properties and to carry on its business as now being conducted.

(b)          Outstanding Stock. All issued and outstanding shares of capital stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable.

(c)           Authority; Enforceability.  The Company has full corporate power and authority necessary to enter into and deliver this Agreement and to perform its obligations thereunder. This Agreement has been duly authorized, executed and delivered by the Company and is a valid and binding agreement enforceable against the Company in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights generally and to general principles of equity.

(d)          Consents.  No consent, approval, authorization or order of any court or governmental agency or body having jurisdiction over the Company is required for the execution by the Company of this Agreement and compliance and performance by the Company of its obligations hereunder, including, without limitation, the issuance and sale of the Shares.

(e)           No Violation or Conflict.  Assuming the representations and warranties of the Subscriber in Section 3 are true and correct, neither the issuance and sale of the Shares nor the performance of the Company’s obligations under this Agreement and all other agreements entered into by the Company relating thereto by the Company will:

 (i)        violate, conflict with, result in a breach of, or constitute a default (or an event which with the giving of notice or the lapse of time or both would be reasonably likely to constitute a default) under (A) the certificate of incorporation of the Company, (B) to the Company’s knowledge, any decree, judgment, order, law, treaty, rule, regulation or determination applicable to the Company of any court or governmental agency or body having jurisdiction over the Company or over the properties or assets of the Company, (C) the terms of any bond, debenture, note or any other evidence of indebtedness, or any agreement, stock option or other similar plan, indenture, lease, mortgage, deed of trust or other instrument to which the Company is a party, by which the Company is bound, or to which any of the properties of the Company is subject, or (D) the terms of any “lock-up” or similar provision of any underwriting or similar agreement to which the Company is a party except the violation, conflict, breach, or default of which would not have a material adverse effect on the business, operations or financial condition of the Company and its subsidiaries taken as a whole (a “Material Adverse Effect”);

 (ii)       result in the activation of any anti-dilution rights or a reset or re-pricing of any debt or security instrument of any other creditor or equity holder of the Company, nor result in the acceleration of the due date of any borrowing of the Company; or

 (iii)      result in the activation of any piggy-back registration rights of any person or entity holding securities of the Company or having the right to receive securities of the Company.

(f)           The Shares.  The Shares upon issuance in accordance with the terms of this Agreement:

 (i)        are, or will be, free and clear of any security interests, liens, claims or other encumbrances, subject to restrictions upon transfer under the Securities Act and any applicable state securities laws;

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 (ii)       will be duly and validly authorized, and on the date of issuance of the Shares, the Shares will be duly and validly issued, fully paid and nonassessable; and

 (iii)      will not have been issued or sold in violation of any preemptive or other similar rights of the holders of any securities of the Company.

 (g)         Litigation.  There is no pending or, to the best knowledge of the Company, threatened action, suit, proceeding or investigation before any court, governmental agency or body, or arbitrator having jurisdiction over the Company that would affect the execution by the Company or the performance by the Company of its obligations under this Agreement, and all other agreements entered into by the Company relating hereto.  Except as disclosed in the Reports, there is no pending or, to the best knowledge of the Company, basis for or threatened action, suit, proceeding or investigation before any court or governmental agency or body, which litigation if adversely determined could have a Material Adverse Effect.

(h)          Reporting Company.  The Company is a publicly-held company subject to reporting obligations pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and its shares of Common Stock are registered pursuant to Section 12(g) of the Exchange Act. The Company has timely filed all reports and other materials required to be filed under the Exchange Act during the preceding twelve months.

(i)           Information Concerning the Company.  The Reports contain all material information relating to the Company and its operations and financial condition as of their respective dates that is required by the Exchange Act to be disclosed therein.  Since the date of the financial statements included in the Reports, there has been no Material Adverse Effect not disclosed in the Reports. The Reports, at the time of filing, did not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstances when made.

 (j)          No Integrated Offering.  Neither the Company, nor any of its affiliates, nor any person acting on its or their behalf, has directly or indirectly made any offers or sales of any security or solicited any offers to buy any security under circumstances that would cause the offer of the Shares pursuant to this Agreement to be integrated with prior offerings by the Company so as to invalidate any exemptions under the Securities Act for the offer and sale of the Shares.

(k)          No General Solicitation.  Neither the Company, nor any of its affiliates, nor to its knowledge, any person acting on its or their behalf, has engaged in any form of general solicitation or general advertising (within the meaning of Reg. D under the Securities Act) in connection with the offer or sale of the Shares.

(l)           No Material Undisclosed Events or Circumstances.  Since the date of the last Report filed under the Exchange Act, no event or circumstance has occurred or exists with respect to the Company or its business, operations or financial condition, that, under applicable law, rule or regulation, requires the filing of a Report prior to the date hereof that has not been so filed.

(m)         Correctness of Representations.  The Company represents that the foregoing representations and warranties are true and correct as of the date hereof in all material respects, and, unless the Company otherwise notifies the Subscriber prior to the Closing, shall be true and correct in all material respects as of the Closing Date.

(n)          Survival.  The foregoing representations and warranties shall survive the applicable Closing Date for a period of three years.

5.           Reg. D Offering.  The offer and issuance of the Shares to the Subscriber is being made pursuant to the exemption from the registration provisions of the Securities Act afforded by Section 4(2) or Section 4(6) of the Securities Act and/or Rule 506 of Reg. D promulgated thereunder.

6.           Covenants of the Company.  The Company covenants and agrees with the Subscriber as follows:

(a)          Exchange Act Filings.  The Company shall file a Form 8-K with the SEC disclosing the transactions contemplated by this Agreement within the time period specified therefor by the rules and regulations under the Exchange Act. The Company agrees to file a Form D with respect to the Shares as required under Reg. D.

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(b)          Reporting Requirements.  Until all of the Shares have been resold or transferred by the Subscriber, or, if earlier, two years after the applicable Closing Date, the Company will use commercially reasonable best efforts (i) not to take any action or file any document (whether or not permitted by the Securities Act or the Exchange Act or the rules thereunder) to terminate or suspend the registration of the shares of the Company’s Common Stock under the Exchange Act and (ii) to continue the listing of the shares of the Company’s Common stock on the Over-the-Counter Bulletin Board or other established trading market.

7.           Registration Rights. The Company hereby grants the following registration rights to holders of the Shares.

(a)          Registration Statement.   The Company shall file with the SEC as soon as practical a “shelf” registration statement on an appropriate form, or shall file with the SEC as soon as practical an amendment to its currently filed shelf registration statement (either the “Registration Statement”) covering the resale of the Shares and shall use its commercially reasonable best efforts to cause the Registration Statement to be declared effective as soon as practicable.

(b)          Registration Procedures. In connection with the Registration Statement, the Company will:

(i)           prepare and file with the SEC such amendments and supplements to the Registration Statement and the prospectus used in connection therewith as may be necessary to keep such Registration Statement effective with respect to the Subscriber until such time as all of the Shares owned by the Subscriber may be resold without restriction under the Securities Act; and

(ii)           immediately notify the Subscriber when the prospectus included in the Registration Statement is required to be delivered under the Securities Act, of the happening of any event of which the Company has knowledge as a result of which the prospectus contained in such Registration Statement, as then in effect, includes an untrue statement of a material fact or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstances then existing. If the Company notifies the Subscriber to suspend the use of any prospectus until the requisite changes to such prospectus have been made, then the Subscriber shall suspend use of such prospectus.  In such event, the Company will use its commercially reasonable efforts to update such prospectus as promptly as is practicable.

(c)          Provision of Documents etc.  In connection with the Registration Statement, the Subscriber will furnish to the Company in writing such information and representation letters with respect to itself and the proposed distribution by it as reasonably shall be necessary in order to assure compliance with federal and applicable state securities laws. The Company may require the Subscriber, upon five business days’ notice, to furnish to the Company a certified statement as to, among other things, the number of  Shares and the number of other shares of the Company’s Common Stock beneficially owned by the Subscriber and the person that has voting and dispositive control over such shares. The Subscriber covenants and agrees that it will comply with the prospectus delivery requirements of the Securities Act, if applicable, in connection with sales of Shares pursuant to the Registration Statement.

(d)          Expenses.  All expenses incurred by the Company in complying with this section, including, without limitation, all registration and filing fees, printing expenses, fees and disbursements of counsel and independent public accountants for the Company, fees of transfer agents and registrars are called “Registration Expenses.” All underwriting discounts and selling commissions applicable to the sale of the Shares, including any fees and disbursements of any counsel to the Subscriber, are called “Selling Expenses.” The Company will pay all Registration Expenses in connection with the Registration Statement. Selling Expenses in connection with the Registration Statement shall be borne by the applicable Subscriber.

(e)          Indemnification and Contribution.

(i)           The Company will, to the extent permitted by law, indemnify and hold harmless the Subscriber, each officer of the Subscriber, each director of the Subscriber, and each other person, if any, who controls the Subscriber within the meaning of the Securities Act, against any losses, claims, damages or liabilities, joint or several, to which the Subscriber or such other person (a “controlling person”) may become subject under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) (“Claims”) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in the Registration Statement at the time of its effectiveness, any preliminary prospectus or final prospectus contained therein, or any amendment or supplement thereof, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstances when made, and will, subject to the limitations herein, reimburse the Subscriber and each such controlling person for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such Claim; provided, however, that the Company shall not be liable to the Subscriber to the extent that any Claim arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in conformity with information furnished by the Subscriber or any such controlling person in writing specifically for use in the Registration Statement or related prospectus, as amended or supplemented.

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(ii)           The Subscriber will, to the extent permitted by law, indemnify and hold harmless the Company, and each person, if any, who controls the Company within the meaning of the Securities Act, each underwriter, each officer of the Company who signs the Registration Statement and each director of the Company against all Claims to which the Company or such officer, director, underwriter or controlling person may become subject under the Securities Act or otherwise, insofar as such Claims arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in the Registration Statement, any preliminary prospectus or final prospectus contained therein, or any amendment or supplement thereof, or the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, and will reimburse the Company and each such officer, director, underwriter and controlling person for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such loss, claim, damage, liability or action, provided, however, that the Subscriber will be liable hereunder in any such case if and only to the extent that any such Claim arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in reliance upon and in conformity with information pertaining to the Subscriber, as such, furnished in writing to the Company by the Subscriber specifically for use in the Registration Statement or related prospectus, as amended or supplemented.

(iii)           Promptly after receipt by an indemnified party hereunder of notice of the commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party hereunder, notify the indemnifying party in writing thereof, but the omission so to notify the indemnifying party shall not relieve it from any liability which it may have to such indemnified party other than under this section and shall only relieve it from any liability which it may have to such indemnified party under this section except and only if and to the extent the indemnifying party is materially prejudiced by such omission. In case any such action shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate in and, to the extent it shall wish, to assume and undertake the defense thereof with counsel satisfactory to such indemnified party, and, after notice from the indemnifying party to such indemnified party of its election so to assume and undertake the defense thereof, the indemnifying party shall not be liable to such indemnified party under this section for any legal expenses subsequently incurred by such indemnified party in connection with the defense thereof other than reasonable costs of investigation and of liaison with counsel so selected; provided, however, that, if the defendants in any such action include both the indemnified party and the indemnifying party and the indemnified party shall have reasonably concluded that there may be reasonable defenses available to it which are different from or additional to those available to the indemnifying party or if the interests of the indemnified party reasonably may be deemed to conflict with the interests of the indemnifying party, the indemnified parties, as a group, shall have the right to select one separate counsel and to assume such legal defenses and otherwise to participate in the defense of such action, with the reasonable expenses and fees of such separate counsel and other expenses related to such participation to be reimbursed by the indemnifying party as incurred. The indemnifying party shall not be liable for any settlement of any such proceeding affected without its written consent, which consent shall not be unreasonably withheld.

(iv)           In order to provide for just and equitable contribution in the event of joint liability under the Securities Act in any case in which either (i) the Subscriber, or any controlling person of the Subscriber, makes a claim for indemnification pursuant to this section but it is judicially determined (by the entry of a final judgment or decree by a court of competent jurisdiction and the expiration of time to appeal or the denial of the last right of appeal) that such indemnification may not be enforced in such case notwithstanding the fact that this section provides for indemnification in such case, or (ii) contribution under the Securities Act may be required on the part of the Subscriber or controlling person of the Subscriber in circumstances for which indemnification is not provided under this section, then, and in each such case, the Company and the Subscriber will contribute to the aggregate losses, claims, damages or liabilities to which they may be subject (after contribution from others) in a manner that reflects, as near as practicable, the economic effect of the foregoing provisions of this section. Notwithstanding the foregoing, no person or entity guilty of fraudulent misrepresentation (within the meaning of Section 10(f) of the Securities Act) will be entitled to contribution from any person or entity who was not guilty of such fraudulent misrepresentation.

(f)          Delivery of Unlegended Shares.

(i)           Within three business days (such business day, the “Unlegended Shares Delivery Date”) after the business day on which the Company has received (i) a notice that Shares have been sold either pursuant to, and in compliance with, the Registration Statement or Rule 144 under the Securities Act and (ii) in the case of sales under Rule 144, customary representation letters of the Subscriber and Subscriber’s broker regarding compliance with the requirements of Rule 144, the Company at its expense, (A) shall deliver the Shares so sold without any restrictive legends relating to the Securities Act (the “Unlegended Shares”); and (B) shall cause the transmission of the certificates representing the Unlegended Shares together with a legended certificate representing the balance of the unsold Shares, if any, to the Subscriber at the address specified in the notice of sale, via express courier, by electronic transfer or otherwise on or before the Unlegended Shares Delivery Date.  Transfer fees shall be the responsibility of the Subscriber.

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(ii)           In lieu of delivering physical certificates representing the Unlegended Shares, if the Company’s transfer agent is participating in the Depository Trust Company (“DTC”) Fast Automated Securities Transfer program, upon request of the Subscriber, so long as the certificates therefor do not bear a legend and the Subscriber is not obligated to return such certificate for the placement of a legend thereon, the Company shall use its best efforts to cause its transfer agent to electronically transmit the Unlegended Shares by crediting the account of Subscriber’s broker with DTC through its Deposit/Withdrawal at Custodian system.  Such delivery must be made on or before the Unlegended Shares Delivery Date but is subject to the cooperation of the Subscriber’s broker (the so-called DTC participant).

(iii)           The Subscriber agrees that the removal of the restrictive legend from certificates representing the Shares as set forth in this section is predicated upon the Company’s reliance that the Subscriber will sell any Shares pursuant to either the registration requirements of the Securities Act, including any applicable prospectus delivery requirements, or an exemption therefrom.

8.           Miscellaneous.

(a)          Notices.  All notices, demands, requests, consents, approvals, and other communications required or permitted hereunder shall be in writing and, unless otherwise specified herein, shall be (i) personally served, (ii) delivered by reputable overnight courier service with charges prepaid, or (iii) transmitted by fax, addressed, if to the Company, to Chief Financial Officer, American DG Energy Inc., 45 First Avenue, Waltham, MA 02451, fax: (781) 622-1027, and if to the Subscriber, to the Subscriber at the address set forth on the signature pages hereto or to such other address as such party shall have specified most recently by written notice.

(b)          Amendments; Waivers.  No provision of this Agreement may be waived or amended except in a written instrument signed, in the case of an amendment, by the Company and the Subscriber.  No waiver of any default with respect to any provision, condition or requirement of this Agreement shall be deemed to be a continuing waiver in the future or a waiver of any subsequent default or a waiver of any other provision, condition or requirement hereof, nor shall any delay or omission of either party to exercise any right hereunder in any manner impair the exercise of any such right.

(c)          Legal Fees.   Each party shall pay its own legal fees and expenses in connection with the transactions contemplated by this Agreement.

(d)          Entire Agreement; Assignment.  This Agreement and other documents delivered in connection herewith represent the entire agreement between the parties hereto with respect to the subject matter hereof.  Neither the Company nor the Subscriber have relied on any representations not contained or referred to in this Agreement and the documents delivered herewith.  No right or obligation of either party shall be assigned by that party without prior notice to and the written consent of the other party.

(e)          Counterparts/Execution.  This Agreement may be executed in any number of counterparts and by the different signatories hereto on separate counterparts, each of which, when so executed, shall be deemed an original, but all such counterparts shall constitute but one and the same instrument.  Signatures to this Agreement may be delivered by fax or by scan/email.

(f)           Law Governing this Agreement.  This Agreement shall be governed by and construed in accordance with the laws of the State of Delaware without regard to principles of conflicts of laws. Any action brought by either party against the other concerning the transactions contemplated by this Agreement shall be brought only in the state courts of Massachusetts or in the federal courts located in Massachusetts.  The parties and the individuals executing this Agreement and other agreements referred to herein or delivered in connection herewith on behalf of the Company agree to submit to the jurisdiction of such courts and waive trial by jury.

(g)          Equitable Adjustment.   The Shares and the purchase price Per Share shall be equitably adjusted to offset the effect of stock splits, stock dividends, and distributions of property or equity interests of the Company to its shareholders prior to the Second Closing.

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Signature Page and Questionnaire – First Closing October 2009

The Subscriber hereby executes this Subscription Agreement. By initialing the appropriate space below, the Subscriber hereby represents that the Subscriber is:

_____________ (initials)	a corporation, a business trust, or a partnership, not formed for the specific purpose of acquiring the Shares, with total assets in excess of $5,000,000.
_____________ (initials)	a natural person whose individual net worth, or joint net worth with his or her spouse, exceeds $1,000,000.
_____________ (initials)	a natural person who had an individual income in excess of $200,000 in each of the two most recent years, or joint income with his or her spouse in excess of $300,000 in each of those years, and has a reasonable expectation of reaching the same income level in the current year.
_____________ (initials)	a trust with total assets in excess of $5,000,000, not formed for the specific purpose of acquiring the Shares.
_____________ (initials)	an entity in which all of the equity owners fall within one of the categories set forth above.

U.S. $2.10
Share purchase price at First Closing é	Subscriber’s name é
Number of Shares purchased at First Closing é	Subscriber’s signature é
$
Aggregate dollar amount being purchased at First Closing é	Address of the Subscriber ê

Agreed and Accepted - American DG Energy Inc.:	Phone number:
By:	Email address:
Date:	U.S. Tax ID # (if any):

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Signature Page and Questionnaire – Second Closing December 2009

The Subscriber hereby executes this Subscription Agreement. By initialing the appropriate space below, the Subscriber hereby represents that the Subscriber is:

_____________ (initials)	a corporation, a business trust, or a partnership, not formed for the specific purpose of acquiring the Shares, with total assets in excess of $5,000,000.
_____________ (initials)	a natural person whose individual net worth, or joint net worth with his or her spouse, exceeds $1,000,000.
_____________ (initials)	a natural person who had an individual income in excess of $200,000 in each of the two most recent years, or joint income with his or her spouse in excess of $300,000 in each of those years, and has a reasonable expectation of reaching the same income level in the current year.
_____________ (initials)	a trust with total assets in excess of $5,000,000, not formed for the specific purpose of acquiring the Shares.
_____________ (initials)	an entity in which all of the equity owners fall within one of the categories set forth above.

U.S. $3.10
Share purchase price at Second Closing é	Subscriber’s name é
Number of Shares purchased, at the Subscriber’s option, at Second Closing é	Subscriber’s signature é
$
Aggregate dollar amount being purchased, at the Subscriber’s option, at Second Closing é	Address of the Subscriber ê

Agreed and Accepted - American DG Energy Inc.:	Phone number:
By:	Email address:
Date:	U.S. Tax ID # (if any):

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EX-10.20

Exhibit 10.20

THIS WARRANT AND THE COMMON STOCK ISSUABLE UPON EXERCISE HEREOF HAVE NOT BEEN REGISTERED OR QUALIFIED FOR SALE UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES LAWS AND MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR QUALIFICATION OR AN EXEMPTION THEREFROM UNDER SAID ACT AND ANY STATE SECURITIES LAWS WHICH MAY BE APPLICABLE. THE COMPANY MAY REQUIRE AN OPINION OF COUNSEL BEFORE IT EFFECTS ANY TRANSFER ON ITS BOOKS AND RECORDS OF THIS WARRANT OR THE COMMON STOCK ISSUABLE UPON EXERCISE HEREOF.

WARRANT TO PURCHASE

SHARES OF COMMON STOCK

OF

AMERICAN DG ENERGY INC.

 Key Terms/Definitions:

“Company”:	American DG Energy Inc., a Delaware corporation
“Holder”:	Hayden IR
“Common Stock”:	Common Stock, $.001 par value per share of the Company
Number of shares of Common Stock issuable on exercise of Warrant (subject to adjustment):	12,000 shares
Price paid to purchase Warrant:	$0.00
Exercise Price per share of Common Stock (subject to adjustment):	$2.98
Vesting Schedule:	4,000 Shares vest (i.e., become exercisable) on October 1, 2009; 4,000 Shares vest on February 1, 2010; 4,000 Shares vest on June 1, 2010; provided that at each such vesting date the Hayden IR agreement with the Company remains in effect and the Holder has complied fully with the terms thereof through the applicable vesting date.
Expiration Date:	May 30, 2013

THIS IS TO CERTIFY that, for value received and subject to the provisions hereinafter set forth, that the Holder, or permitted assigns, is entitled to purchase from the Company at any time on or after the date hereof and on or before the Expiration Date the number of shares of Common Stock set forth in the table above, subject to the terms, provisions and conditions hereinafter set forth, at the Exercise Price per share.

The Company shall give the Holder written notice of the pendency of the Expiration Date at least 10 days, but not more than 60 days, prior to the Expiration Date. If the Company fails to serve the Expiration Notice upon the Holder within the required time period, the Expiration Date shall be deemed to have been extended and this Warrant shall continue to be exercisable by the Holder until 10 days after the Company delivers a delinquent Expiration Notice to the Holder referencing the new, extended Expiration Date.

Tender of the price paid to purchase this Warrant shall be made by delivery of a personal or bank check payable to the Company or by wire transfer to the Company’s designated bank account, together with one executed copy of this Warrant.

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SECTION 1.          EXERCISE OF WARRANT

This Warrant may be exercised in whole or in part at any time by the surrender of this Warrant (with the subscription form at the end hereof duly completed and executed) at the principal office of the Company.

For an exercise for cash, the subscription form shall be accompanied by payment to the Company of the aggregate Exercise Price for the shares being purchased. Any such payment shall be by check payable to the order of the Company.

For a “cashless exercise,” the Holder shall notify the Company in its subscription form of its election to utilize cashless exercise, in which event the Company shall issue to the Holder a number of shares of Common Stock determined as follows:

X = Y [(A-B)/A]

where:

X = the number of shares of Common Stock to be issued to the Holder.

Y = the number of shares of Common Stock with respect to which this Warrant is being exercised.

A = the closing price of the Common Stock on its principal trading market on the trading day immediately prior to the exercise date.

B = the Exercise Price then in effect.

Notwithstanding any other provision hereof, if an exercise of any portion of this Warrant is to be made in connection with a public offering or sale of the Company, the exercise of any portion of this Warrant may, at the election of the Holder, be conditioned upon the consummation of the public offering or sale of the Company, in which case such exercise shall not be deemed to be effective concurrently with the consummation of such transaction.

If this Warrant is exercised in respect of less than all of the shares of Common Stock at the time purchasable hereunder, the Holder shall be entitled to receive a new Warrant of like tenor to this Warrant covering the number of shares in respect of which this Warrant shall not have been exercised.

The Common Stock issuable upon the exercise of this Warrant shall be deemed to have been issued to the Holder at the time of such exercise, and the Holder shall be deemed for all purposes to have become the record holder of the Common Stock at such time.  Certificates for shares of the Common Stock purchased upon exercise or partial exercise of this Warrant shall be delivered by the Company to Holder within five business days after the date of exercise.

This Warrant and all rights and options hereunder shall expire on the Expiration Date (as the same may be modified as provided herein), and shall be wholly null and void to the extent this Warrant is not exercised before it expires.

SECTION 2.          RESERVATION

The Company will at all times prior to the Expiration Date reserve and keep available such number of authorized shares of its Common Stock solely for the purpose of issuance upon the exercise of the rights represented by this Warrant as herein provided for, as may at any time be issuable upon the exercise of this Warrant.

SECTION 3.          VESTING

The Holder may exercise this Warrant on or after the date of this Warrant grant for the number of vested shares of Common Stock set forth on the cover page hereof, but only in accordance with the Vesting Schedule also set forth on the cover page. The foregoing rights are cumulative and may be exercised only before the Expiration Date. If at any time the Hayden IR agreement with the Company terminates, no additional shares shall vest.

SECTION 4.          STOCK DIVIDENDS, ETC.

The per share Exercise Price and the number of shares deliverable hereunder shall be adjusted as hereinafter set forth:

Section 4.1. Stock Dividends, Subdivisions and Combinations.  In case after the date hereof the Company shall:

(a)            take a record of the holders of its Common Stock for the purpose of entitling them to receive a dividend payable in, or other distribution of, Common Stock, or

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(b)            subdivide its outstanding shares of Common Stock into a larger number of shares of Common Stock, or

(c)            combine its outstanding shares of Common Stock into a smaller number of shares of Common Stock,

then the per share Exercise Price shall be adjusted, for the purpose of preserving the economic value of this Warrant, to the price determined by multiplying the per share Exercise Price in effect immediately prior to such subdivision or combination or the taking of a record of holders in respect of such payment or distribution, as the case may be (each, a “Triggering Event”) by a fraction (i) the numerator of which shall be the total number of outstanding shares of Common Stock of the Company immediately prior to such Triggering Event, and (ii) the denominator of which shall be the total number of outstanding shares of Common Stock of the Company immediately after such Triggering Event.

Section 4.2.           Adjustment of Number of Shares Purchasable.  Upon each adjustment of the per share Exercise Price, the number of shares of Common Stock subsequently purchasable hereunder shall be an amount equal to the quotient derived by dividing the aggregate Exercise Price in effect immediately before such adjustment by the per share Exercise Price in effect immediately following such adjustment or readjustment.

Section 4.3.           Notice of Adjustments.  Whenever the per share Exercise Price or number of shares deliverable upon exercise of this Warrant shall be adjusted pursuant to this Section 4, the Company shall promptly prepare a certificate signed by the President or a Vice President and by the Treasurer or an Assistant Treasurer of the Company setting forth, in reasonable detail, the event requiring the adjustment, the amount of the adjustment, the method by which such adjustment was calculated (including a description of the basis on which the Board of Directors of the Company made any determination hereunder), and shall promptly cause copies of such certificate to be mailed (by first class mail, postage prepaid) to the Holder.

SECTION 5.          MERGERS, CONSOLIDATIONS, SALES

In the case of any consolidation or merger of the Company with another entity (regardless of whether the Company is the surviving entity), or the sale of all or substantially all of its assets to another entity, or any reorganization or reclassification of the Common Stock or other equity securities of the Company, then, as a condition of such consolidation, merger, sale, reorganization or reclassification, lawful and adequate provision shall be made whereby the Holder shall thereafter have the right to receive upon the basis and upon the terms and conditions specified herein and in lieu of the shares of Common Stock immediately theretofore purchasable hereunder, such shares of stock, securities or assets (including, without limitation, cash), if any, as may (by virtue of such consolidation, merger, sale, reorganization or reclassification) be issued or payable with respect to or in exchange for a number of outstanding shares of Common Stock equal to the number of shares of Common Stock immediately theretofore so purchasable hereunder had such consolidation, merger, sale, reorganization or reclassification not taken place, and in any such case appropriate provisions shall be made with respect to the rights and interests of the Holder to the end that the provisions hereof shall thereafter be applicable, as nearly as may be, in relation to any shares of stock, securities or assets thereafter deliverable upon exercise of this Warrant.  The Company shall not effect any such consolidation, merger or sale unless (a) the Company provides the holder hereof with not less than 10 days prior written notice of such consolidation, merger or sale (provided that the failure to give such notice shall not affect the validity of such corporate event), and (b) prior to the consummation thereof, the successor entity (if other than the Company) resulting from consolidation or merger or the entity purchasing such assets assumes, by written instrument, the obligation to deliver to each such holder such shares of stock, securities or assets as, in accordance with the foregoing provisions, such holder may be entitled to acquire.

SECTION 6.          DISSOLUTION OR LIQUIDATION

If the Company declares or pays a dividend upon the Common Stock payable otherwise than in cash out of earnings or earned surplus (determined in accordance with generally accepted accounting principles, consistently applied) except for a stock dividend payable in shares of Common Stock (a “Liquidating Dividend”), then the Company shall pay to the Holder at the time of payment thereof the Liquidating Dividend which would have been paid to such holder on the Common Stock had this Warrant been fully exercised immediately prior to the date on which a record is taken for such Liquidating Dividend, or, if no record is taken, the date as of which the record holders of Common Stock entitled to such dividends are to be determined.

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SECTION 7.         NOTICE OF DIVIDENDS; PAYMENTS

If the Board of Directors of the Company shall declare any dividend or other distribution on any class of its Common Stock except by way of a stock dividend payable in Common Stock on its Common Stock, the Company shall mail notice thereof to the Holder not less than 10 days prior to the record date fixed for determining shareholders entitled to participate in such dividend or other distribution, and the Holder shall be entitled to receive, as a consent fee, cash or other property from the Company in an amount and of the same type (cash or property) equal to that which the holder would have been entitled to receive if the unexercised portion hereof had been exercised as of the record date of such dividend or distribution.

SECTION 8.         NO FRACTIONAL SHARES

No fractional shares shall be issued upon the exercise of this Warrant under any circumstances.

SECTION 9.         FULLY PAID STOCK

The Company covenants and agrees to take all such actions necessary to ensure that the shares of stock represented by each and every certificate for its Common Stock to be delivered on the exercise of the purchase rights herein provided for shall, at the time of such delivery, be validly issued and outstanding and be fully paid and nonassessable.  In addition, the Company shall take all such actions as may be necessary to ensure that all such shares of Common Stock may be so issued without violation of any applicable law or governmental regulation or any requirements of any trading market or securities exchange upon which shares of Common Stock may be listed.

SECTION 10.       CLOSING OF TRANSFER BOOKS

The right to exercise this Warrant shall not be suspended during any period that the stock transfer books of the Company for its Common Stock may be closed.  The Company shall not be required, however, to deliver certificates of its Common Stock upon such exercise while such books are duly closed for any purpose, but the Company may postpone the delivery of the certificates for the Common Stock until the opening of such books, and they shall, in such case, be delivered forthwith upon the opening thereof, or as soon as practicable thereafter.

SECTION 11. RESTRICTIONS ON TRANSFERABILITY OF WARRANTS AND SHARES; COMPLIANCE WITH LAWS

Notwithstanding anything contained in this Warrant to the contrary, the terms and provisions of this Section 11 of this Warrant remain in full force and effect at all times and shall survive the Expiration Date.

Section 11.1.            In General.  This Warrant and the shares of Common Stock issued upon the exercise hereof shall not be transferable except upon the conditions hereinafter referred to, which conditions are intended to ensure compliance with the provisions of the Securities Act of 1933, as amended (or any similar Federal statute at the time in effect) (the “Securities Act”), and any applicable state securities laws in respect of the transfer of this Warrant or any such shares.  Any attempt to transfer such Warrant or such shares except in accordance with the terms hereof shall, to the extent legally enforceable, be void.

Section 11.2.            Restrictive Legends.  Each Warrant and each certificate for shares of Common Stock issued upon the exercise of any Warrant shall bear a customary restrictive legend relating to securities laws compliance until counsel for the Company determines that such legend is no longer legally required.  This Warrant and any shares of Common Stock issuable upon exercise hereof may be transferred only in accordance with the provisions of such legend, including the legend set forth on the first page hereof.

Section 11.3.            Accredited Investor.  The initial Holder of this Warrant represents that he is an a “accredited investor” as defined in the rules and regulations under the Securities Act.

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SECTION 12.        PARTIAL EXERCISE AND PARTIAL ASSIGNMENT

If this Warrant is exercised in part only, the holder hereof shall be entitled to receive a new Warrant covering the number of shares in respect of which this Warrant shall not have been exercised as provided in Section 1.  If this Warrant is partially assigned, this Warrant shall be surrendered at the principal office of the Company (with the partial assignment form at the end hereof duly executed), and thereupon a new Warrant shall be issued to the Holder covering the number of shares not assigned and setting forth the proportionate aggregate Exercise Price applicable to such shares not assigned.  The assignee of such partial assignment of this Warrant shall also be entitled to receive a new Warrant of like tenor to this Warrant covering the number of shares so assigned and setting forth the proportionate aggregate Exercise Price applicable to such assigned shares. If this Warrant is assigned in full, this Warrant shall be surrendered at the principal office of the Company (with the full assignment form at the end hereof duly executed), and thereupon a new Warrant of like tenor to this Warrant shall be issued to the assignee covering the number of shares of Common Stock then issuable upon exercise of this Warrant.

SECTION 13.        WARRANT DENOMINATIONS

Warrants are issuable or transferable in the denomination of 1,000 shares or any integral multiple thereof (as nearly as may be practicable and subject to required adjustments hereunder), and the Warrants of each denomination are interchangeable upon surrender thereof at the office of the Company for Warrants of other denominations, but aggregating the same number of shares as the Warrants so surrendered.  All Warrants will be dated the same date as this Warrant.

SECTION 14.        LOST, STOLEN WARRANTS, ETC.

In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company may issue a new Warrant of like date, tenor and denomination and deliver the same in exchange and substitution for and upon surrender and cancellation of the mutilated Warrant, or in lieu of the Warrant lost, stolen or destroyed, upon receipt of evidence satisfactory to the Company of the loss, theft or destruction of such Warrant, and upon receipt of indemnity satisfactory to the Company. All warrants hereafter issued in exchange or substitution for this Warrant shall be substantially in the form hereof.

SECTION 15.        WARRANT HOLDER RIGHTS

This Warrant does not confer upon the holder hereof any right to vote or to consent or to receive notice as a shareholder of the Company, as such, in respect of any matters whatsoever, or any other rights or liabilities as a shareholder, prior to the exercise hereof as hereinbefore provided.

SECTION 16.        SEVERABILITY

Should any part of this Warrant for any reason be declared invalid, such decision shall not affect the validity of any remaining portion, which remaining portion shall remain in force and effect as if this Warrant had been executed with the invalid portion thereof eliminated, and it is hereby declared the intention of the parties hereto that they would have executed and accepted the remaining portion of this Warrant without including therein any such part, parts or portion which may, for any reason, be hereafter declared invalid.

SECTION 17.        GOVERNING LAW

This Warrant shall be governed by the laws of the State of Delaware.

IN WITNESS WHEREOF, the Company has caused this Warrant to be signed by a duly authorized officer.

Dated: October 1, 2009

AMERICAN DG ENERGY INC.

By: 

John N. Hatsopoulos

Chief Executive Officer

The initial Warrant Holder hereby confirms

the representations and covenants contained

in Section 11:

___________________________________

Hayden IR                      

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SUBSCRIPTION

(1)           The Holder hereby elects to exercise the above-referenced Warrant with respect to the following number of shares of Common Stock:  __________________. 

(2)           The Holder intends that payment of the Exercise Price shall be made as (check one):

o  Cash exercise

o  Cashless exercise

(3)           If the Holder has elected a cash exercise, the Holder shall pay the sum of $ ______________ to the Company in accordance with the terms of the Warrant.

(4)           Pursuant to this subscription, the Company shall deliver to the Holder the number of shares of Common Stock determined in accordance with the terms of the Warrant.

Dated:	HOLDER:
	Print name ↑
	By:
	Title:

6

FULL ASSIGNMENT

FOR VALUE RECEIVED, ____________________________ hereby sells, assigns and transfers unto_____________________ the within Warrant and all rights evidenced thereby and does irrevocably constitute and appoint ___________________________, attorney, to transfer the said Warrant on the books of the within-named Company.

Assignor

Dated:

PARTIAL ASSIGNMENT

FOR VALUE RECEIVED _________________________ hereby sells, assigns and transfers unto that portion of the within Warrant and the rights evidenced thereby which will on the date hereof entitle the holder to purchase shares of Common Stock of American DG Energy Inc. and irrevocably constitutes and appoints attorney, to transfer that part of the said Warrant on the books of the within-named Company.

Assignor

Dated

7

EX-23.2

CORRESP

February 3, 2010

Via EDGAR

H. Christopher Owings, Assistant Director

Mail Stop 3561

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, NE

Washington, DC 20549

Re:	American DG Energy Inc.
	Amendment No. 1 to Registration Statement on Form S-3
	File No. 333-163972
	Filed January 13, 2010

Dear Mr. Owings:

 The purpose of this letter is to respond to your letter of January 26, 2010 with respect to the above-captioned filing. For ease of reference, our responses are keyed to your comments. We are concurrently filing an amendment to the registration statement to reflect the changes we describe below.

Determination of Offering Price and Market Data, page 3

COMMENT No.1

 Please update the number of holders to the latest practicable date. Please also update the percentage ownership in your selling stockholder table so that they are based on the number of shares outstanding as of a more recent date than December 22, 2009.

RESPONSE TO COMMENT No.1

 We have revised our disclosure as requested and updated the number of holders as of February 2, 2010, and updated the percentage ownership in our selling stockholder table so that they are based on the number of shares outstanding as of February 2, 2010.

Selling Stockholders, page 4

COMMENT No.2

 We reviewed your response to comment five in our letter dated January 11, 2010 and reissue this comment in part. Please tell us weather Integrated Risk Facilities Holdings, Inc. Stuart Farber or any of your other selling stockholders is a broker-dealer or is affiliated with a broker-dealer. If any of your selling stockholders are broker-dealers, please disclose that he, she, or it is an “underwriter” within the meaning of the Securities Act of 1933. Also, if applicable, you should revise this section, your prospectus cover page, and your Plan of Distribution section to state that the selling stock holder is a broker-dealer, and to state that the selling stockholder is an underwriter with respect to the shares that it is offering for resale.

Securities and Exchange Commission

February 3, 2010

Page 2

RESPONSE TO COMMENT No.2

In response to your comment please note that Integrated Risk Facilities Holdings, Inc. or Stuart Farber is not a broker-dealer neither is affiliated with a broker-dealer. Integrated Risk Facilities Holdings, Inc. is an insurance company with an address at 40 Fulton Street, New York, NY 10030 and Mr. Stuart Farber may be deemed to exercise voting and/or dispositive power with respect to these shares. In response to the second part of your comment please note that we have revised the Selling Stockholders section, our prospectus cover page, and our Plan of Distribution section to state that certain of the selling stock holders are broker-dealers, and to state that certain of the selling stockholders are underwriters with respect to the shares that they are offering for resale.

Exhibit 5.1

COMMENT No.3

Please also have counsel revise its opinion to refer to the current registration statement on Form S-3, as opposed to Form S-1.

RESPONSE TO COMMENT No.3

We have revised our disclosure as requested and provided with an updated opinion from our counsel.

*     *    *

In connection with responding to your comments, we further acknowledge that:

· should the Commission or the staff, acting pursuant to delegated authority, declare the filing effective, it does not foreclose the Commission from taking any action with respect to the filing;

· the action of the Commission or the staff, acting pursuant to delegated authority, in declaring the filling effective, does not relieve the company from its full responsibility for the adequacy of the disclosure in the filing; and

· the company may not assert staff comments and the declaration of effectiveness as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

*     *    *

Please call me at (781) 622-1117 or our attorney, Edwin Miller of Sullivan & Worcester in Boston, at (617) 338-2447 if you have any questions or require additional information.

Sincerely,
AMERICAN DG ENERGY INC.
/s/ Anthony S. Loumidis
By:	Anthony S. Loumidis
	Chief Financial Officer

cc:  Mara Ransom, Branch Chief

       Catherine Brown, Staff Attorney