FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person *   MARXE AUSTIN W & GREENHOUSE DAVID M 2. Date of Event Requiring Statement (Month/Day/Year) 03/23/2012 3. Issuer Name and Ticker or Trading Symbol PLUG POWER INC [PLUG] (Last) (First) (Middle) C/O SPECIAL SITUATIONS FUNDS, 527 MADISON AVENUE, SUITE 2600 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) NEW YORK, NY 10022 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 8,511,620 (1) I (1) By Limited Partnership (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Warrant	05/25/2011	05/31/2016	Common Stock	2,801,762 (2) (3)	$ 2.27	I (2) (3)	By Limited Partnerships (2) (3)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MARXE AUSTIN W & GREENHOUSE DAVID M C/O SPECIAL SITUATIONS FUNDS 527 MADISON AVENUE, SUITE 2600 NEW YORK, NY 10022	Â	  X	Â	Â

Signatures

Austin W. Marxe		04/02/2012
**Signature of Reporting Person		Date
David M. Greenhouse		04/02/2012
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse). They share voting and investment control over all securities owned by Special Situations Fund III QP, L.P. (SSFQP), Special Situations Cayman Fund, L.P. (Cayman), Special Situations Private Equity Fund, L.P. (PE), Special Situations Technology Fund, L.P. (Tech) and Special Situations Technology Fund II, L.P. (Tech2). 3,158,900 shares of Common Stock are held by SSFQP, 950,000 shares of Common Stock are held by Cayman, 581,385 shares of Common Stock are held by PE, 530,942 shares of Common Stock are held by Tech and 3,290,393 shares of Common Stock are held by Tech2. The interest of Marxe and Greenhouse in the shares of Common Stock owned by SSFQP, Cayman, PE, Tech and Tech2 is limited to the extent of his pecuniary interest.
(2)	This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse). They share voting and investment control over all securities owned by, Special Situations Private Equity Fund, LP (PE), Special Situations Technology Fund, L.P. (Tech) and Special Situations Technology Fund II, L.P. (Tech2). 419,145 Warrants are owned by PE, 231,239 Warrants are owned by Tech and 1,469,616 Warrants are owned by Tech2. The interest of Marxe and Greenhouse in the shares of Warrants owned by PE, Tech and Tech2 are limited to the extent of his pecuniary interest.
(3)	The warrant may be exercised to the extent that the total number of shares of Common Stock then beneficially owned does not exceed 4.99% of the outstanding shares. The Holder may request an increase up to 9.99% of the outstanding shares, effective on the 61st day after notice is given to the Company.

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