UNITED STATES

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SCHEDULE 14A

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PLUG POWER INC.

(Name of Registrant as Specified In Its Charter)

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News Release

FOR IMMEDIATE RELEASE

PLUG POWER ANNOUNCES FURTHER ADJOURNMENT OF ANNUAL MEETING

LATHAM, NY – May 29, 2009 – Plug Power Inc. (NASDAQ: PLUG), a leader in providing clean, reliable energy solutions, today announced that it has further adjourned its 2009 Annual Meeting of Stockholders while it continues discussions with the company’s largest stockholder regarding its vote. The adjourned meeting will be held at 10:00 a.m. ET on Wednesday, June 17, 2009 at the offices of Plug Power Inc., 968 Albany-Shaker Road, Latham, New York 12110. Stockholders may submit or revoke proxies until the annual meeting. The record date for the annual meeting is March 31, 2009.

Plug Power Inc. Safe Harbor Statement

This communication contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including but not limited to statements regarding our growth plan. We believe that it is important to communicate our future expectations to our investors. However, there may be events in the future that we are not able to accurately predict or control and that may cause our actual results to differ materially from the expectations we describe in our forward-looking statements, including, without limitation, the risk that unit orders will not ship, be installed and/or convert to revenue, in whole or in part; Plug Power’s ability to develop commercially viable energy products; the cost and timing of developing Plug Power’s energy products; market acceptance of Plug Power’s energy products; Plug Power’s ability to manufacture energy products on a large-scale commercial basis; competitive factors, such as price competition and competition from other traditional and alternative energy companies; the cost and availability of components and parts for Plug Power’s energy products; Plug Power’s ability to establish relationships with third parties with respect to product development, manufacturing, distribution and servicing and the supply of key product components; the cost and availability of fuel and fueling infrastructures for Plug Power’s energy products; Plug Power’s ability to protect its Intellectual Property; Plug Power’s ability to lower the cost of its energy products and demonstrate their reliability; the cost of complying with current and future governmental regulations; the impact of deregulation and restructuring of the electric utility industry on demand for Plug Power’s energy products; and other risks and uncertainties discussed under “Item IA—Risk Factors” in Plug Power’s annual report on Form 10-K for the fiscal year ended December 31, 2008, filed with the Securities and Exchange Commission (“SEC”) on March 16, 2009, and the reports Plug Power files from time to time with the SEC. Plug Power does not intend to and undertakes no duty to update the information contained in this communication.

Important Information

In connection with the solicitation of proxies, on April 9, 2009, Plug Power Inc. filed a definitive proxy statement with the Securities and Exchange Commission (the “SEC”) in connection with the Company’s 2009 Annual Meeting. PLUG POWER’S STOCKHOLDERS ARE STRONGLY ADVISED TO READ THE DEFINITIVE PROXY MATERIALS AND ANY OTHER RELEVANT SOLICITATION MATERIALS FILED BY PLUG POWER WITH THE SEC BEFORE MAKING ANY VOTING OR INVESTMENT DECISION BECAUSE THESE DOCUMENTS CONTAIN IMPORTANT INFORMATION. The Company’s proxy statement and any other materials filed by the Company with the SEC can be obtained free of charge at the SEC’s web site at www.sec.gov. The Company’s definitive proxy materials are also available for free from Plug Power at http://www.plugpower.com/, or by writing to Plug Power Inc., 968 Albany-Shaker Road, Latham, New York 12110, Attention: Corporate Secretary. The contents of the websites referenced above are not deemed to be incorporated by reference into the proxy statement.

Plug Power Inc. and its directors, nominees and executive officers may be deemed to be participants in the solicitation of proxies from the stockholders of Plug Power in connection with the Company’s 2009 Annual Meeting of Stockholders. Information concerning the interests of participants in the solicitation of proxies is included in the definitive proxy statement filed by Plug Power with the SEC on April 9, 2009 in connection with its 2009 Annual Meeting of Stockholders.

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Media Contact: Katrina Fritz Intwala Plug Power Inc. Phone: (518) 782-7700 ext. 1360 Investor Relations Contact: Cathy Yudzevich Plug Power Inc. Phone: (518) 782-7700 ext. 1448