Ownership Submission
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 *
Marsh Andrew
   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)
President and CEO
(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   20,000 A $ 2.42 (1) 38,465 (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   15,000   05/31/2011 05/31/2016 Plug Power Common Stock 15,000 $ 2.42 (1) 161,850 (3) D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Marsh Andrew
968 ALBANY SHAKER ROAD
LATHAM, NY 12110		   X     President and CEO

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 166,186 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: 40,000 granted 4/8/2008 exercise price $35.80; 250 granted on 5/20/2009 exercise price $9.50; 106,600 granted on 4/13/2011 exercise price of $6.10.

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