8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 2, 2010

CALPINE CORPORATION

(Exact name of registrant as specified in its charter)

Delaware	1-12079	77-0212977
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

717 Texas Avenue, Suite 1000, Houston, Texas 77002

(Addresses of principal executive offices and zip codes)

Registrant’s telephone number, including area code: (713) 830-8775

Not applicable

(Former name or former address if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

TABLE OF CONTENTS

ITEM 1.01 — ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT

ITEM 9.01 — FINANCIAL STATEMENTS AND EXHIBITS

SIGNATURES

EXHIBIT INDEX

1

ITEM 1.01 — ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT

On April 2, 2010, Calpine Corporation and its indirect wholly owned subsidiaries, Riverside Energy Center, LLC and Calpine Development Holdings, Inc. (the “Sellers”), reached an agreement with Public Service Company of Colorado (“PSCo”), a Colorado corporation and a wholly owned subsidiary of Xcel Energy Inc., to sell 100% of the interests in Rocky Mountain Energy Center, LLC, (“Rocky Mountain Energy Center”) and Blue Spruce Energy Center, LLC, (“Blue Spruce Energy Center”) for $739 million, subject to certain working capital adjustments upon closing. The sale is expected to close in December 2010.

The Rocky Mountain Energy Center is a 621 MW combined-cycle, natural gas-fired power plant, located in Keenesburg, CO that began commercial operations in 2004. The Blue Spruce Energy Center is a 310 MW simple-cycle, natural gas-fired power plant, located in Aurora, CO that began commercial operations in 2003. Both power plants currently provide power and capacity to PSCo under power purchase agreements, which are set to expire in 2013 and 2014. Under the agreement, the Sellers will use commercially reasonable efforts to cause Rocky Mountain Energy Center and Blue Spruce Energy Center to continue to operate and maintain the above power plants in the ordinary course through closing of the sale.

The sale is subject to customary closing conditions including approvals under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 and by the Federal Energy Regulatory Commission and the Colorado Public Service Commission (“CPUC”). The agreement is subject to termination if the closing does not occur on or before the date the 270th day after the later of the filing of the application for CPUC approval and the filing of the application for Federal Energy Regulatory Commission approval as well as certain other customary early termination provisions.

See additional information in the Press Release furnished as exhibit 99.1.

ITEM 9.01 — FINANCIAL STATEMENTS AND EXHIBITS

(d) Exhibits

Exhibit No.	Description
99.1	Calpine Corporation Press Release dated April 5, 2010.*

* Furnished herewith.

2

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	CALPINE CORPORATION
	By:	/s/    ZAMIR RAUF
		Zamir Rauf
		Executive Vice President and
		Chief Financial Officer
Date: April 5, 2010

3

EXHIBIT INDEX

Exhibit No.	Description
99.1	Calpine Corporation Press Release dated April 5, 2010.*

* Furnished herewith.

4

EX-99.1

Exhibit 99.1

April 5, 2010

Xcel Energy to purchase Calpine plants

Acquisition benefits customers, utility’s renewable energy efforts

DENVER—Xcel Energy (NYSE:XEL) and Calpine Corporation (NYSE:CPN) today announced that Public Service Company of Colorado (PSCo), an Xcel Energy company, will purchase two of Calpine’s power plants near Denver, which currently provide power to the utility under power purchase agreements.

The $739 million acquisition stems from an offer by Calpine into a competitive bid process that was part of Xcel Energy’s 2007 Colorado Resource Plan, and was the least cost option among many bids for needed generating resources. The agreement is dependent on regulatory agency approval.

The plants to be purchased are the 621-megawatt Rocky Mountain Energy Center, located near Hudson, Colo., which began commercial operation in 2004, and produces electricity using efficient combined-cycle technology, and the 310-megawatt simple-cycle Blue Spruce Energy Center, located in Aurora, Colo., which began operation in 2003. The plants can collectively provide enough electrical power to meet the needs of approximately 700,000 Colorado households.

“This agreement will be good for our customers because these assets, which are already an integral part of our system, will continue to provide reliable and reasonably priced energy for many years,” said David Eves, president and CEO of Public Service Company of Colorado, an Xcel Energy company. “Knowing that these plants will be part of our long-term generation mix will also help us to more effectively manage system reliability as we strive to meet the state’s newly increased renewable energy standard.”

Thad Hill, Calpine’s Chief Commercial Officer, added, “We have been pleased to provide PSCo with clean, efficient and reliable energy solutions for Colorado ratepayers since 2003. We are confident that the 931 MW of capacity developed and operated by Calpine will continue to serve Colorado’s energy needs for the foreseeable future. We appreciate the hard work and dedication of the energy professionals that have operated these facilities during our ownership.”

- More -

- Xcel Energy news release format—p. 2 of 2 -

Xcel Energy is a major U.S. electricity and natural gas company that provides a comprehensive portfolio of energy-related products and services to 3.4 million electricity customers and 1.9 million natural gas customers through its regulated operating companies in eight Western and Midwestern states. Company headquarters are located in Minneapolis. More information is available at xcelenergy.com.

Founded in 1984, Calpine Corporation is a major U.S. power company, currently capable of delivering nearly 25,000 megawatts of clean, cost-effective, reliable and fuel-efficient power to customers and communities in 16 states in the United States and Canada. Calpine Corporation is committed to helping meet the needs of an economy that demands more and cleaner sources of electricity. Calpine owns, leases and operates low-carbon, natural gas-fired and renewable geothermal power plants. Using advanced technologies, Calpine generates power in a reliable and environmentally responsible manner for the customers and communities it serves. Please visit our Web site at www.calpine.com for more information.

This news release includes forward-looking statements that are subject to certain risks, uncertainties and assumptions. Such forward-looking statements are intended to be identified in this document by the words “will,” “can,” “anticipate,” “expect,” “potential” and similar expressions, and include, among others, those concerning expected strategic and operational plans, as well as assumptions, expectation, intentions or beliefs about future events. Actual results may vary materially and Xcel Energy and PSCo undertake no obligation to update such statements. Factors that could cause actual results to differ materially include, but are not limited to, those risk factors listed from time to time by Xcel Energy and PSCo in reports filed with the Securities and Exchange Commission (SEC), including Risk Factors in Item 1A and Exhibit 99.01 of each of Xcel Energy’s and PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2009.

In addition to historical information, this release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Words such as “believe,” “intend,” “expect,” “anticipate,” “plan,” “may,” “will” and similar expressions identify forward-looking statements. Such statements include, among others, those concerning expected financial performance and strategic and operational plans, as well as assumptions, expectations, predictions, intentions or beliefs about future events. You are cautioned that any such forward-looking statements are not guarantees of future performance and that a number of risks and uncertainties could cause actual results to differ materially from those anticipated in the forward-looking statements. Please see the risks identified in this release or in Calpine’s reports and registration statements filed with the Securities and Exchange Commission, including, without limitation, the risk factors identified in its Annual Report on Form 10-K for the year ended Dec. 31, 2009. These filings are available by visiting the Securities and Exchange Commission’s Web site at www.sec.gov or Calpine’s Web site at www.calpine.com. Actual results or developments may differ materially from the expectations expressed or implied in the forward-looking statements, and Calpine undertakes no obligation to update any such statements.

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