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 *
HELMER MAUREEN O
  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) _____ Other (specify below)
(Last)
(First)
(Middle)
968 ALBANY SHAKER ROAD
3. Date of Earliest Transaction (Month/Day/Year)
09/20/2011
(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

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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
Option to Purchase Plug Power Common Stock $ 1.93 09/20/2011   A   65,000 (1)     (2) 09/20/2021 Plug Power Common Stock 65,000 $ 0 88,200 (3) D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
HELMER MAUREEN O
968 ALBANY SHAKER ROAD
LATHAM, NY 12110
  X      

Signatures

 /s/ Gerard L. Conway, Jr., Attorney in Fact   09/30/2011
**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) Awarded pursuant to Plug Power's 2011 Stock Option and Incentive Plan.
(2) Consists of an option to acquire common stock granted on September 20, 2011 with respect to which: 21,667 shares will become exercisable on September 20, 2012; 21,667 shares will become exercisable on September 20, 2013; 21,666 shares will become exercisable on September 20, 2014.
(3) 1,500 granted on 2/12/2004 exercise price $93.90; 1,000 granted on 5/20/2004 exercise price $75.00; 1,000 granted on 6/1/2005 exercise price $62.20; 1,200 granted on 6/28/2006 exercise price $46.40; 1,200 granted on 5/17/2007 exercise price $29.80; 1,200 granted on 5/21/2008 exercise price $32.10; 1,200 granted on 5/20/2009 exercise price $9.50; 12,500 granted 5/20/2009 exercise price $9.50; 1,200 granted on 5/19/2010 exercise price $4.80; 1,200 granted on 5/12/2011 exercise price $5.10.

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