Nature of Operations	12 Months Ended
Dec. 31, 2013
Summary of Significant Accounting Policies
Nature of Operations	1. Nature of Operations *Description of Business* Plug Power Inc., or the Company, is a leading provider of alternative energy technology focused on the design, development, commercialization and manufacture of fuel cell systems for the industrial off-road (forklift or material handling) market. We are 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, or 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. We sell and continue to develop fuel cell product solutions to replace lead-acid batteries in material handling vehicles and industrial trucks for some of North America’s largest distribution and manufacturing businesses. We are focusing our efforts on material handling applications (forklifts) at multi-shift high volume manufacturing and high throughput distribution sites where our products and services provide a unique combination of productivity, flexibility and environmental benefits. Our current product line includes: GenDrive, a hydrogen fueled PEM fuel cell system providing power to material handling vehicles; GenKey, our turn-key solution offering complete simplicity to customers transitioning their material handling vehicles to fuel cell power; GenFuel, our hydrogen fueling delivery system; and GenCare, our ongoing maintenance program for both the GenDrive fuel cells and GenFuel products. We sell our products worldwide, with a primary focus on North America, through our direct product sales force, leveraging relationships with original equipment manufacturers, or OEMs, and their dealer networks. We are party to a joint venture based in France with Axane, S.A. under the name Hypulsion, to develop and sell hydrogen fuel cell systems for the European material handling market. We sell to businesses, government agencies and commercial consumers. We were organized in the State of Delaware on June 27, 1997. 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. *Liquidity* 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, funding the growth in our GenKey “turn-key” solution which also includes the installation of our customer’s hydrogen infrastructure as well as delivery of the hydrogen molecule, 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. If we are unable to fund our operations without additional external financing and therefore cannot sustain future operations, we may be required to delay, reduce and/or cease our operations and/or seek bankruptcy protection. We have experienced and continue to experience negative cash flows from operations and net losses. The Company incurred net losses attributable to common shareholders of $62.8 million, $31.9 million and $27.5 million for the years ended December 31, 2013, 2012 and 2011, respectively, and has an accumulated deficit of $849.4 million at December 31, 2013. Substantially all of our accumulated deficit has been incurred in connection with our operating expenses, research and development expenses and from general and administrative costs associated with our operations. We expect that for fiscal year 2014, our operating cash burn will be approximately $10-$15 million. Net cash used in operating activities for the year ended December 31, 2013 was $26.9 million. Additionally, on December 31, 2013, we had cash and cash equivalents of $5.0 million and net working capital of $11.1 million. This compares to $9.4 million and $6.9 million, respectively, at December 31, 2012. On January 15, 2014, we completed an underwritten public offering of 10,000,000 shares of common stock and accompanying warrants to purchase 4,000,000 shares of common stock. The shares and the warrants were sold together in a fixed combination, with each combination consisting of one share of common stock and 0.40 of a warrant to purchase one share of common stock, at a price of $3.00 per fixed combination for gross proceeds of $30.0 million. The securities were placed with a single institutional investor. The warrants have an exercise price of $4.00 per share, are immediately exercisable and will expire on January 15, 2019. Net proceeds, after underwriting discounts and commissions and other estimated fees and expenses were approximately $28.0 million. On March 11, 2014, we completed an underwritten public offering of 3,902,440 shares of common stock. The shares were sold at $5.74 per share for gross proceeds of approximately $22.4 million. The shares were placed with a single institutional investor. Net proceeds, after underwriting discounts and commissions and other estimated fees and expenses were approximately $21.5 million. Between January 1, 2014 and March 21, 2014, we have received an additional $18.2 million from the exercise of previously issued common stock warrants. To date, we have funded our operations primarily through public and private offerings of common and preferred stock, a sale-leaseback of our building, our previous line of credit and maturities and sales of our available-for-sale securities. The Company believes that its current cash, cash equivalents, cash generated from future sales, cash generated from the exercise of outstanding warrants, and cash generated from recent public offerings will provide sufficient liquidity to fund operations for at least the next twelve months. This projection is based on our current expectations regarding product sales, cost structure, cash burn rate and operating assumptions.

Nature of Operations

12 Months Ended

Dec. 31, 2013

Summary of Significant Accounting Policies

1. Nature of Operations

Description of Business

Plug Power Inc., or the Company, is a leading provider of alternative energy technology focused on the design, development, commercialization and manufacture of fuel cell systems for the industrial off-road (forklift or material handling) market.

We are 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, or 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.

We sell and continue to develop fuel cell product solutions to replace lead-acid batteries in material handling vehicles and industrial trucks for some of North America’s largest distribution and manufacturing businesses. We are focusing our efforts on material handling applications (forklifts) at multi-shift high volume manufacturing and high throughput distribution sites where our products and services provide a unique combination of productivity, flexibility and environmental benefits. Our current product line includes: GenDrive, a hydrogen fueled PEM fuel cell system providing power to material handling vehicles; GenKey, our turn-key solution offering complete simplicity to customers transitioning their material handling vehicles to fuel cell power; GenFuel, our hydrogen fueling delivery system; and GenCare, our ongoing maintenance program for both the GenDrive fuel cells and GenFuel products.

We sell our products worldwide, with a primary focus on North America, through our direct product sales force, leveraging relationships with original equipment manufacturers, or OEMs, and their dealer networks. We are party to a joint venture based in France with Axane, S.A. under the name Hypulsion, to develop and sell hydrogen fuel cell systems for the European material handling market. We sell to businesses, government agencies and commercial consumers.

We were organized in the State of Delaware on June 27, 1997.

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.

Liquidity

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, funding the growth in our GenKey “turn-key” solution which also includes the installation of our customer’s hydrogen infrastructure as well as delivery of the hydrogen molecule, 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. If we are unable to fund our operations without additional external financing and therefore cannot sustain future operations, we may be required to delay, reduce and/or cease our operations and/or seek bankruptcy protection.

We have experienced and continue to experience negative cash flows from operations and net losses. The Company incurred net losses attributable to common shareholders of $62.8 million, $31.9 million and $27.5 million for the years ended December 31, 2013, 2012 and 2011, respectively, and has an accumulated deficit of $849.4 million at December 31, 2013. Substantially all of our accumulated deficit has been incurred in connection with our operating expenses, research and development expenses and from general and administrative costs associated with our operations. We expect that for fiscal year 2014, our operating cash burn will be approximately $10-$15 million.

Net cash used in operating activities for the year ended December 31, 2013 was $26.9 million. Additionally, on December 31, 2013, we had cash and cash equivalents of $5.0 million and net working capital of $11.1 million. This compares to $9.4 million and $6.9 million, respectively, at December 31, 2012.

On January 15, 2014, we completed an underwritten public offering of 10,000,000 shares of common stock and accompanying warrants to purchase 4,000,000 shares of common stock. The shares and the warrants were sold together in a fixed combination, with each combination consisting of one share of common stock and 0.40 of a warrant to purchase one share of common stock, at a price of $3.00 per fixed combination for gross proceeds of $30.0 million. The securities were placed with a single institutional investor. The warrants have an exercise price of $4.00 per share, are immediately exercisable and will expire on January 15, 2019. Net proceeds, after underwriting discounts and commissions and other estimated fees and expenses were approximately $28.0 million.

On March 11, 2014, we completed an underwritten public offering of 3,902,440 shares of common stock. The shares were sold at $5.74 per share for gross proceeds of approximately $22.4 million. The shares were placed with a single institutional investor. Net proceeds, after underwriting discounts and commissions and other estimated fees and expenses were approximately $21.5 million.

Between January 1, 2014 and March 21, 2014, we have received an additional $18.2 million from the exercise of previously issued common stock warrants.

To date, we have funded our operations primarily through public and private offerings of common and preferred stock, a sale-leaseback of our building, our previous line of credit and maturities and sales of our available-for-sale securities. The Company believes that its current cash, cash equivalents, cash generated from future sales, cash generated from the exercise of outstanding warrants, and cash generated from recent public offerings will provide sufficient liquidity to fund operations for at least the next twelve months. This projection is based on our current expectations regarding product sales, cost structure, cash burn rate and operating assumptions.