SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                ----------------

                                  SCHEDULE 13G
                                ----------------


             INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                         Environmental Power Corporation
                                (NAME OF ISSUER)

                     Common Stock, par value $0.01 per share
                         (TITLE OF CLASS OF SECURITIES)

                                    29406L201
                                 (CUSIP NUMBER)

                                 October 11,2007
             (Date of Event which requires Filing of this Statement)

            Check the appropriate box to designate the rule
                   pursuant to which this Schedule is filed:

                                [ ] Rule 13d-1(b)
                                [x] Rule 13d-1(c)
                                [ ] Rule 13d-1(d)






                             (Page 1 of 14 Pages)
------------------

* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).





CUSIP No. 29406L201                    13G                    PAGE 2 of 14 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Partners Renewable Energy Fund, L.P.
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Delaware
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------
BENEFICIALLY   (6)  SHARED VOTING POWER
                    359,000
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    359,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          359,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
          2.31%
--------------------------------------------------------------------------------
    (12) TYPE OF REPORTING PERSON **
              PN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 29406L201                    13G                    PAGE 3 of 14 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Renewable Energy Offshore Fund, Ltd.
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          British Virgin Islands
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------
BENEFICIALLY   (6)  SHARED VOTING POWER
                    520,100
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    520,100
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          520,100
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
          3.35%
--------------------------------------------------------------------------------
    (12) TYPE OF REPORTING PERSON **
              CO
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 29406L201                    13G                    PAGE 4 of 14 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Advisory Partners
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Connecticut
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------
BENEFICIALLY   (6)  SHARED VOTING POWER
                    970,000
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    970,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          970,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
          6.25%
--------------------------------------------------------------------------------
    (12) TYPE OF REPORTING PERSON **
              PN; IA
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 29406L201                    13G                    PAGE 5 of 14 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Partners I
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Connecticut
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------
BENEFICIALLY   (6)  SHARED VOTING POWER
                    359,000
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    359,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          359,000
--------------------------------------------------------------------------------
    (10) CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
          2.31%
--------------------------------------------------------------------------------
    (12) TYPE OF REPORTING PERSON **
              PN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 29406L201                    13G                    PAGE 6 of 14 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Philip J. Hempleman
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Delaware
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------
BENEFICIALLY   (6)  SHARED VOTING POWER
                    970,000
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    970,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          970,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
          6.25%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               IN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 29406L201                    13G                    PAGE 7 of 14 PAGES


ITEM 1(a).  NAME OF ISSUER:

            The name of the issuer is Environmental Power Corporation (the
"Company").

ITEM 1(b).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:
            One Cate Street 4th Floor, Portsmouth, New Hampshire 03801

ITEM 2(a).  NAME OF PERSON FILING:

      This statement is filed by:

      (i)   Ardsley  Partners  Renewable  Energy Fund,  L.P., a Delaware limited
            partnership ("Ardsley Energy"), with respect to the shares of Common
            Stock,  par value $0.01 per share ("Common Stock") directly owned by
            it;
      (ii)  Ardsley  Renewable  Energy  Offshore  Fund,  Ltd., a British  Virgin
            Islands corporation ("Ardsley Energy Offshore"), with respect to the
            shares of Common Stock directly owned by it;
      (v)   Ardsley   Advisory   Partners,   a  New  York  general   partnership
            ("Ardsley")  which serves as  Investment  Manager of Ardsley  Energy
            Offshore and the  Investment  Adviser of Ardsley  Energy and certain
            managed  accounts,  with  respect  to the  shares  of  Common  Stock
            directly  owned by Ardsley Energy  Offshore,  Ardsley Energy and the
            managed accounts;
      (vi)  Ardsley  Partners  I,  a  New  York  general  partnership  ("Ardsley
            Partners") which serves as General Partner of Ardsley Energy; and
      (vii) Philip J.  Hempleman  ("Mr.  Hempleman"),  the  Managing  Partner of
            Ardsley and Ardsley  Partners,  with respect to the shares of Common
            Stock  owned by Ardsley  Energy,  Ardsley  Energy  Offshore  and the
            managed accounts.

            The foregoing persons are hereinafter sometimes collectively
referred to as the "Reporting Persons." Any disclosures herein with respect to
persons other than the Reporting Persons are made on information and belief
after making inquiry to the appropriate party.

ITEM 2(b).  ADDRESS OF PRINCIPAL OFFICE OR, IF NONE, RESIDENCE:

      The address of the business office of each of the Reporting Persons,  with
the  exception  of  Ardsley  Energy  Offshore,  is 262 Harbor  Drive,  Stamford,
Connecticut 06902.

      The address of the registered office of Ardsley Energy Offshore is Romasco
Place, Wickhams Cay 1, Roadtown Tortola, British Virgin Islands.





CUSIP No. 29406L201                    13G                    PAGE 8 of 14 PAGES

ITEM 2(c).  CITIZENSHIP:

      Ardsley Energy is a Delaware limited partnership.  Ardsley Energy Offshore
is British Virgin Islands corporation. Ardsley and Ardsley Partners are New York
general partnerships. Mr. Hempleman is a United States Citizen.

ITEM 2(d).  TITLE OF CLASS OF SECURITIES: Class A Common Stock, par value $0.01
per share

ITEM 2(e).  CUSIP NUMBER:  29406L201

ITEM 3.   IF THIS STATEMENT IS FILED PURSUANT TO RULES 13d-1(b), OR 13d-2(b),
CHECK WHETHER THE PERSON FILING IS A:

          (a) [ ]   Broker or dealer registered under Section 15 of the Act

          (b) [ ]   Bank as defined in Section 3(a)(6) of the Act


          (c) [ ]   Insurance Company as defined in Section 3(a)(19) of the Act

          (d) [ ]   Investment   Company  registered  under  Section  8  of  the
                    Investment Company Act

          (e) [ ]   Investment  Adviser  registered  under  Section  203  of the
                    Investment Advisers Act of 1940

          (f) [ ]   Employee Benefit Plan,  Pension Fund which is subject to the
                    provisions of the Employee Retirement Income Security Act of
                    1974 or Endowment Fund; see Rule 13d- 1(b)(1)(ii)(F)

          (g) [ ]   Parent  Holding  Company,   in  accordance  with  Rule  13d-
                    1(b)(ii)(G); see item 7

          (h) [ ]   Group, in accordance with Rule 13d-1(b)(1)(ii)(H)

If this statement is filed pursuant to Rule 13d-1(c), check the box. [X]





CUSIP No. 29406L201                    13G                    PAGE 9 of 14 PAGES

ITEM 4.   OWNERSHIP.

The percentages used n the Item 4 are calculated based upon 15,522,490 shares of
Common Stock issued and outstanding as reported by Bloomberg as of December 31,
2007.

Based upon the last quarterly report filed by the Company on Form 10-Q for the
quarterly period ended September 30, 2007, the number of shares of Common Stock
issued and outstanding as of September 30, 2007 was 10,267,784. Using this
number, the percentages beneficially owned by (i) Ardsley Partners Renewable
Energy Fund, L.P. Ardsley Partners I; (ii) Ardsley Renewable Energy Offshore
Fund, Ltd.; and (iii) Ardsley Advisory Partners and Philip J. Hempleman would be
3.50%; 5.07%; and 9.45%, respectively.

      A.    Ardsley Partners Renewable Energy Fund, L.P.
            (a)    Amount beneficially owned: 359,000
            (b)    Percent of class: 2.31%
            (c)    (i)   Sole Power to vote or direct the vote: -0-
                   (ii)  Shared power to vote or direct the vote: 359,000
                   (iii) Sole power to dispose or direct the disposition: -0-
                   (iv)  Shared power to dispose or direct the disposition:
                         359,000

      B.    Ardsley Renewable Energy Offshore Fund, Ltd.
            (a)    Amount beneficially owned: 520,100
            (b)    Percent of class: 3.35%
            (c)    (i) Sole Power to vote or direct the vote: -0-
                   (ii)  Shared power to vote or direct the vote: 520,100
                   (iii) Sole power to dispose or direct the disposition: -0-
                   (iv)  Shared power to dispose or direct the disposition:
                         520,100

      C.    Ardsley Advisory Partners
            (a)    Amount beneficially owned: 970,000
            (b)    Percent of class: 6.25%
            (c)    (i)   Sole Power to vote or direct the vote: -0-
                   (ii)  Shared power to vote or direct the vote: 970,000
                   (iii) Sole power to dispose or direct the disposition: -0-
                   (iv)  Shared power to dispose or direct the disposition:
                         970,000

      D. Ardsley Partners I
            (a)    Amount beneficially owned: 359,000
            (b)    Percent of class: 2.31%
            (c)    (i)   Sole Power to vote or direct the vote: -0-
                   (ii)  Shared power to vote or direct the vote: 359,000
                   (iii) Sole power to dispose or direct the disposition: -0-
                   (iv)  Shared power to dispose or direct the disposition:
                         359,000

      E. Philip J. Hempleman
            (a)    Amount beneficially owned: 970,000
            (b)    Percent of class: 6.25%
            (c)    (i)   Sole Power to vote or direct the vote: -0-
                   (ii)  Shared power to vote or direct the vote: 970,000
                   (iii) Sole power to dispose or direct the disposition: -0-
                   (iv)  Shared power to dispose or direct the disposition:
                         970,000

ITEM 5.   OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.
      Not applicable.





CUSIP No. 29406L201                    13G                   PAGE 10 of 14 PAGES


ITEM 6.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

      Ardsley,  the  Investment  Manager  of  Ardsley  Energy  Offshore  and the
Investment Adviser of certain managed accounts, has the power to vote and direct
the  disposition  of the  proceeds  from the sale of the shares of Common  Stock
owned by Ardsley Energy Offshore and the managed  accounts,  and accordingly may
be deemed the direct "beneficial owner" of such shares of Common Stock.

      Ardsley,  the Investment  Adviser of Ardsley  Energy,  shares the power to
vote and direct the  disposition  of the proceeds from the sale of the shares of
Common Stock owned by Ardsley Energy, and, accordingly, may be deemed the direct
"beneficial owner" of such shares of Common Stock.

      Ardsley Partners,  the General Partner of Ardsley Energy, shares the power
to vote and  direct  the  disposition  of the  shares of Common  Stock  owned by
Ardsley Energy, and, accordingly, may be deemed the direct "beneficial owner" of
such shares of Common Stock.

      Mr.  Hempleman is the Managing Partner of Ardsley and Ardsley Partners and
in that capacity  directs their operations and therefore may be deemed to be the
indirect  "beneficial  owner" of the  shares of Common  Stock  owned by  Ardsley
Energy  Offshore,  Ardsley  Energy  and  the  managed  accounts.  Mr.  Hempleman
disclaims  beneficial ownership of all of the Shares of Common Stock reported in
this 13G

ITEM 7.   IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
          THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY. Not
          applicable.

ITEM 8.   IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.
          Not applicable.

ITEM 9.   NOTICE OF DISSOLUTION OF GROUP.
          Not applicable.

ITEM 10.  CERTIFICATION.

     Each of the Reporting Persons hereby makes the following certification:

      By signing below I certify,  to the best of my knowledge  and belief,  the
securities  referred to above were acquired in the ordinary  course of business,
were not  acquired  for the purpose of and do not have the effect of changing or
influencing  the control of the issuer of such  securities and were not acquired
in connection with or as a participant in any  transaction  having such purposes
or effect.






CUSIP No. 29406L201                    13G                   PAGE 11 of 14 PAGES
                            SIGNATURE

          After  reasonable  inquiry  and to the  best of  their  knowledge  and
belief, the undersigned certify that the information set forth in this statement
is true, complete and correct.


DATED: as of February 14, 2008



                              ARDSLEY PARTNERS RENEWABLE ENERGY FUND, L.P.
                              BY:  ARDSLEY PARTNERS I,
                                   GENERAL PARTNER


                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  General Partner


                              ARDSLEY RENEWABLE ENERGY OFFSHORE FUND, LTD.


                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  Director



                              ARDSLEY ADVISORY PARTNERS
                              By:  ARDSLEY PARTNERS I
                                   GENERAL PARTNER


                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  General Partner



                              ARDSLEY PARTNERS I

                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  General Partner





CUSIP No. 29406L201                    13G                   PAGE 12 of 14 PAGES




                              PHILIP J. HEMPLEMAN, INDIVIDUALLY


                              BY:/s/ STEVE NAPOLI*
                                 ----------------
                                  Steve Napoli
                                  As attorney in fact for
                                  Philip J. Hempleman


*  Evidence of Power of Attorney was filed with the Schedule 13G filed on
   February 15, 2006 (Acc-no: 0000902664-06-000895) and is incorporated by
   reference into this filing.




CUSIP No. 29406L201                    13G                   PAGE 13 of 14 PAGES

                                    EXHIBIT 1
               JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k)(1)

          The undersigned  acknowledge and agree that the foregoing statement on
Schedule  13G is  filed  on  behalf  of each of the  undersigned  and  that  all
subsequent  amendments to this statement shall be filed on behalf of each of the
undersigned  without the necessity of filing additional joint filing statements.
The undersigned acknowledge that each shall be responsible for the timely filing
of such  amendments,  and for the  completeness  and accuracy of the information
concerning him, her or it contained herein, but shall not be responsible for the
completeness  and accuracy of the  information  concerning the other entities or
persons,  except to the extent that he, she or it knows or has reason to believe
that such information is inaccurate.

Dated as of February 14, 2008



                              ARDSLEY PARTNERS RENEWABLE ENERGY FUND, L.P.
                              BY:  ARDSLEY PARTNERS I,
                                   GENERAL PARTNER


                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  General Partner


                              ARDSLEY RENEWABLE ENERGY OFFSHORE FUND, LTD.


                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  Director



                              ARDSLEY ADVISORY PARTNERS

                              By:  ARDSLEY PARTNERS I
                                   GENERAL PARTNER

                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  General Partner





CUSIP No. 29406L201                    13G                   PAGE 14 of 14 PAGES


                              ARDSLEY PARTNERS I

                              BY:/s/ STEVE NAPOLI
                                 ----------------
                                  Steve Napoli
                                  General Partner


                              PHILIP J. HEMPLEMAN, INDIVIDUALLY


                              BY:/s/ STEVE NAPOLI *
                                 ----------------
                                  Steve Napoli
                                  Attorney-in-fact
                                  for Philip J. Hempleman





*  Evidence of Power of Attorney was filed with the Schedule 13G filed on
   February 15, 2006 (Acc-no: 0000902664-06-000895) and is incorporated by
   reference into this filing.