Nature of Operations	9 Months Ended
Sep. 30, 2011
Nature Of Operations [Abstract]
Nature of Operations	1. Nature of Operations *Description of Business* Plug Power Inc., or the Company, is a leading provider of alternative energy technology and is involved in the design, development, commercialization and manufacture of fuel cell systems for the industrial off-road (forklift or material handling) market. Plug Power has also provided product development for the back-up and stationary power markets worldwide. Effective April 1, 2010, the Company was no longer considered a development stage enterprise because its principal operations began to provide more than insignificant revenues as the Company received orders from repeat customers, increased its customer base and had a significant backlog. Prior to April 1, 2010, the Company was considered a development stage enterprise because substantially all of its resources and efforts were aimed at the discovery of new knowledge that could lead to significant improvement in fuel cell reliability and durability, and the establishment, expansion and stability of markets for our products. The Company is focused on proton exchange membrane, or PEM, fuel cell and fuel processing technologies and fuel cell/battery hybrid technologies, from which multiple products are available. A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity and heat without combustion. Hydrogen is derived from hydrocarbon fuels such as liquid petroleum gas (LPG), natural gas, propane, methanol, ethanol, gasoline or biofuels. Hydrogen can also be obtained from the electrolysis of water. Hydrogen can be purchased directly from industrial gas providers or can be produced on-site at consumer locations. The Company concentrates its efforts on developing, manufacturing and selling our hydrogen-fueled PEM GenDrive^® products on commercial terms for industrial off-road (forklift or material handling) applications, with a focus on multi-shift high volume manufacturing and high throughput distribution sites. We have previously invested in development and sales activities for low-temperature remote-prime power GenSys^® products and our GenCore^® product, which is a hydrogen fueled PEM fuel cell system to provide back-up power for critical infrastructure. While Plug Power will continue to service and support GenSys and/or GenCore products on a limited basis, our main focus is our GenDrive product line. The Company sells its products worldwide, with a primary focus on North America, through our direct product sales force, original equipment manufacturers (OEMs) and their dealer networks. We sell to business, industrial and government customers. The Company was incorporated in the State of Delaware on August 13, 1999 and prior to that time operated as a joint venture between Edison Development Corporation and Mechanical Technology Incorporated. The Company’s common stock became listed on The NASDAQ Stock Market on October 29, 1999. In 2007, we merged with and acquired all the assets, liabilities and equity of Cellex Power Products, Inc. (Cellex) and General Hydrogen Corporation (General Hydrogen). Through these acquisitions, and our continued GenDrive product development efforts, Plug Power became the first fuel cell company to offer a complete suite of products: Class 1 - sit-down counterbalance trucks, Class 2 – stand-up reach trucks and Class 3 – rider pallet trucks. The launch of our Class 2 product occurred in January of 2010. Unless the context indicates otherwise, the terms “Company,” “Plug Power,” “we,” “our” or “us” as used herein refers to Plug Power Inc. and its subsidiaries. Although the Company had a significant amount of available-for-sale securities, as described further below, as of December 31, 2010, neither the Company nor any of its subsidiaries was an “investment company” pursuant to the Investment Company Act of 1940, as amended. *Liquidity* We have experienced recurring operating losses and we anticipate incurring substantial additional losses. Including the receipt of $20.7 million in net proceeds from the capital raise completed in the quarter ended September 30, 2011, we had approximately $22.8 million of cash and cash equivalents at September 30, 2011 to fund our future operations. Additionally, on August 9, 2011, we entered into a revolving credit facility arrangement with Silicon Valley Bank (SVB) providing availability to an additional $7 million to support working capital needs (See Note 18, Loan and Security Agreement, of the condensed consolidated financial statements). We believe that our current cash, cash equivalents and cash generated from future sales, in conjunction with the availability of the credit facility, will provide sufficient liquidity to fund operations through the end of 2012. This projection is based on our current expectations regarding product sales, cost structure, cash burn rate and operating assumptions (including those specified in the May 2010 restructuring plan). In the event that our operating expenses are higher than anticipated or the gross margins and shipments of our GenDrive products do not increase as we expect, we may be required to implement contingency plans within our control to conserve and/or enhance our liquidity to meet operating needs. Such plans include: our ability to further reduce discretionary expenses, monetize our real estate assets through a sale-leaseback arrangement and obtain additional funding from licensing the use of our technologies. Our cash requirements relate primarily to working capital needed to operate and grow our business, including funding operating expenses, growth in inventory to support both shipments of new units and servicing the installed base, and continued development and expansion of our products. Our ability to achieve profitability and meet future liquidity needs and capital requirements will depend upon numerous factors, including the timing and quantity of product orders and shipments, the timing and amount of our operating expenses; the timing and costs of working capital needs; the timing and costs of building a sales base; the timing and costs of developing marketing and distribution channels; the timing and costs of product service requirements; the timing and costs of hiring and training product staff; the extent to which our products gain market acceptance; the timing and costs of product development and introductions; the extent of our ongoing and any new research and development programs; and changes in our strategy or our planned activities. As a result, we can provide no assurance that we will be able to fund our operations beyond 2012 without additional external financing. If additional funding is required beyond 2012, alternatives the Company would consider include equity or debt financings, strategic alliances or joint ventures. Under such conditions, if we are unable to obtain additional capital prior to the end of 2012, we may not be able to sustain our future operations into 2013 and may be required to delay, reduce and/or cease our operations and/or seek bankruptcy protection. We cannot assure you that any necessary additional financing will be available on terms favorable to us, or at all. Given the difficult current economic environment, we believe that it could be difficult to raise additional funds and there can be no assurance as to the availability of additional financing or the terms upon which additional financing may be available. Additionally, even if we raise sufficient capital through equity or debt financing, strategic alliances or otherwise, there can be no assurances that the revenue or capital infusion will be sufficient to enable us to develop our business to a level where it will be profitable or generate positive cash flow. If we raise additional funds through the issuance of equity or convertible debt securities, the percentage ownership of our stockholders could be significantly diluted, and these newly issued securities may have rights, preferences or privileges senior to those of existing stockholders. If we incur additional debt, a substantial portion of our operating cash flow may be dedicated to the payment of principal and interest on such indebtedness, thus limiting funds available for our business activities. The terms of any debt securities issued could also impose significant restrictions on our operations. Broad market and industry factors may seriously harm the market price of our common stock, regardless of our operating performance, and may adversely impact our ability to raise additional funds. If we raise additional funds through collaborations and/or licensing arrangements, we might be required to relinquish significant rights to our technologies, or grant licenses on terms that are not favorable to us. As of September 30, 2011, we had cash and cash equivalents of $22.8 million and working capital of $24.5 million.

1. Nature of Operations

Description of Business

Plug Power Inc., or the Company, is a leading provider of alternative energy technology and is involved in the design, development, commercialization and manufacture of fuel cell systems for the industrial off-road (forklift or material handling) market. Plug Power has also provided product development for the back-up and stationary power markets worldwide. Effective April 1, 2010, the Company was no longer considered a development stage enterprise because its principal operations began to provide more than insignificant revenues as the Company received orders from repeat customers, increased its customer base and had a significant backlog. Prior to April 1, 2010, the Company was considered a development stage enterprise because substantially all of its resources and efforts were aimed at the discovery of new knowledge that could lead to significant improvement in fuel cell reliability and durability, and the establishment, expansion and stability of markets for our products.

The Company is focused on proton exchange membrane, or PEM, fuel cell and fuel processing technologies and fuel cell/battery hybrid technologies, from which multiple products are available. A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity and heat without combustion. Hydrogen is derived from hydrocarbon fuels such as liquid petroleum gas (LPG), natural gas, propane, methanol, ethanol, gasoline or biofuels. Hydrogen can also be obtained from the electrolysis of water. Hydrogen can be purchased directly from industrial gas providers or can be produced on-site at consumer locations.

The Company concentrates its efforts on developing, manufacturing and selling our hydrogen-fueled PEM GenDrive^® products on commercial terms for industrial off-road (forklift or material handling) applications, with a focus on multi-shift high volume manufacturing and high throughput distribution sites.

We have previously invested in development and sales activities for low-temperature remote-prime power GenSys^® products and our GenCore^® product, which is a hydrogen fueled PEM fuel cell system to provide back-up power for critical infrastructure. While Plug Power will continue to service and support GenSys and/or GenCore products on a limited basis, our main focus is our GenDrive product line.

The Company sells its products worldwide, with a primary focus on North America, through our direct product sales force, original equipment manufacturers (OEMs) and their dealer networks. We sell to business, industrial and government customers.

The Company was incorporated in the State of Delaware on August 13, 1999 and prior to that time operated as a joint venture between Edison Development Corporation and Mechanical Technology Incorporated. The Company’s common stock became listed on The NASDAQ Stock Market on October 29, 1999. In 2007, we merged with and acquired all the assets, liabilities and equity of Cellex Power Products, Inc. (Cellex) and General Hydrogen Corporation (General Hydrogen). Through these acquisitions, and our continued GenDrive product development efforts, Plug Power became the first fuel cell company to offer a complete suite of products: Class 1 - sit-down counterbalance trucks, Class 2 – stand-up reach trucks and Class 3 – rider pallet trucks. The launch of our Class 2 product occurred in January of 2010.

Unless the context indicates otherwise, the terms “Company,” “Plug Power,” “we,” “our” or “us” as used herein refers to Plug Power Inc. and its subsidiaries.

Although the Company had a significant amount of available-for-sale securities, as described further below, as of December 31, 2010, neither the Company nor any of its subsidiaries was an “investment company” pursuant to the Investment Company Act of 1940, as amended.

Liquidity

We have experienced recurring operating losses and we anticipate incurring substantial additional losses. Including the receipt of $20.7 million in net proceeds from the capital raise completed in the quarter ended September 30, 2011, we had approximately $22.8 million of cash and cash equivalents at September 30, 2011 to fund our future operations. Additionally, on August 9, 2011, we entered into a revolving credit facility arrangement with Silicon Valley Bank (SVB) providing availability to an additional $7 million to support working capital needs (See Note 18, Loan and Security Agreement, of the condensed consolidated financial statements). We believe that our current cash, cash equivalents and cash generated from future sales, in conjunction with the availability of the credit facility, will provide sufficient liquidity to fund operations through the end of 2012. This projection is based on our current expectations regarding product sales, cost structure, cash burn rate and operating assumptions (including those specified in the May 2010 restructuring plan). In the event that our operating expenses are higher than anticipated or the gross margins and shipments of our GenDrive products do not increase as we expect, we may be required to implement contingency plans within our control to conserve and/or enhance our liquidity to meet operating needs. Such plans include: our ability to further reduce discretionary expenses, monetize our real estate assets through a sale-leaseback arrangement and obtain additional funding from licensing the use of our technologies. Our cash requirements relate primarily to working capital needed to operate and grow our business, including funding operating expenses, growth in inventory to support both shipments of new units and servicing the installed base, and continued development and expansion of our products. Our ability to achieve profitability and meet future liquidity needs and capital requirements will depend upon numerous factors, including the timing and quantity of product orders and shipments, the timing and amount of our operating expenses; the timing and costs of working capital needs; the timing and costs of building a sales base; the timing and costs of developing marketing and distribution channels; the timing and costs of product service requirements; the timing and costs of hiring and training product staff; the extent to which our products gain market acceptance; the timing and costs of product development and introductions; the extent of our ongoing and any new research and development programs; and changes in our strategy or our planned activities. As a result, we can provide no assurance that we will be able to fund our operations beyond 2012 without additional external financing. If additional funding is required beyond 2012, alternatives the Company would consider include equity or debt financings, strategic alliances or joint ventures. Under such conditions, if we are unable to obtain additional capital prior to the end of 2012, we may not be able to sustain our future operations into 2013 and may be required to delay, reduce and/or cease our operations and/or seek bankruptcy protection. We cannot assure you that any necessary additional financing will be available on terms favorable to us, or at all. Given the difficult current economic environment, we believe that it could be difficult to raise additional funds and there can be no assurance as to the availability of additional financing or the terms upon which additional financing may be available. Additionally, even if we raise sufficient capital through equity or debt financing, strategic alliances or otherwise, there can be no assurances that the revenue or capital infusion will be sufficient to enable us to develop our business to a level where it will be profitable or generate positive cash flow. If we raise additional funds through the issuance of equity or convertible debt securities, the percentage ownership of our stockholders could be significantly diluted, and these newly issued securities may have rights, preferences or privileges senior to those of existing stockholders. If we incur additional debt, a substantial portion of our operating cash flow may be dedicated to the payment of principal and interest on such indebtedness, thus limiting funds available for our business activities. The terms of any debt securities issued could also impose significant restrictions on our operations. Broad market and industry factors may seriously harm the market price of our common stock, regardless of our operating performance, and may adversely impact our ability to raise additional funds. If we raise additional funds through collaborations and/or licensing arrangements, we might be required to relinquish significant rights to our technologies, or grant licenses on terms that are not favorable to us. As of September 30, 2011, we had cash and cash equivalents of $22.8 million and working capital of $24.5 million.