FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN 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 * MCNAMEE GEORGE C   2. Issuer Name and Ticker or Trading Symbol PLUG POWER INC [PLUG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) Chairman of the Board (Last) (First) (Middle) 968 ALBANY SHAKER ROAD 3. Date of Earliest Transaction (Month/Day/Year) 05/31/2011 (Street) LATHAM, NY 12110 4. If Amendment, Date Original Filed(Month/Day/Year) 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 Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Plug Power Common Stock 05/31/2011   P   40,000 A $ 2.42 (1) 91,096 (2) D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Warrants

$ 3

05/31/2011

P

30,000

05/31/2011

05/31/2016

Plug Power Common Stock

30,000

$ 2.42 (1)

70,500 (3) (4)

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MCNAMEE GEORGE C 968 ALBANY SHAKER ROAD LATHAM, NY 12110	X			Chairman of the Board

Signatures

/s/ Gerard L. Conway, Jr., Attorney in Fact		06/02/2011
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(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)	The shares and warrants were acquired on May 31, 2011 as part of a public offering of shares of common stock and warrants to purchase shares of common stock. Pursuant to the terms of the public offering, each share of common stock was sold together with 0.75 of a 5-year warrant to purchase one share of common stock for an aggregate purchase price of $2.42 per combination.
(2)	On May 19, 2011, Plug Power Inc. effected a 1-for-10 reverse stock split of its common stock, resulting in the reporting person's ownership of 459,873 fewer shares of common stock.
(3)	Existing stock options held by the reporting person have been adjusted to reflect the 1-for-10 reverse stock split as follows: 2,000 granted 5/16/2002 exercise price $102.30; 1,500 granted 5/22/2003 exercise price $50.20; 1,500 granted 5/20/2004 exercise price $75.00; 1,500 granted 6/1/2005 exercise price $62.20; 1,500 granted 6/28/2006 exercise price $46.40; 1,500 granted 5/17/2007 exercise price $29.80; 1,500 granted 5/21/2008 exercise price $32.10; 12,500 granted 2/10/2009 exercise price $9.10; 1,500 granted 5/20/2009 exercise price $9.50; 12,500 granted 5/20/2009 exercise price $9.50; 1,500 granted 5/19/2010 exercise price $4.80; 1,500 granted 5/12/2011 exercise price $5.10.
(4)	This total also accounts for 2,000 options that expired on May 16, 2011.

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