<PAGE>
                                                                   Exhibit 10.65

                     SALES AND MARKETING SERVICES AGREEMENT
                                      AMONG
                ECO FUEL CELLS, LLC, ENERGY CO-OPPORTUNITY, INC.
                                       AND
                                  H POWER CORP.

This Sales and Marketing Services Agreement ("Agreement") is entered into this
10 day of April, 2002 (the "Effective Date"), among H Power Corp., 1373 Broad
Street, Clifton, NJ 07013; H Power Enterprises of Canada, Inc. (together "H
Power"); and ECO Fuel Cells, LLC ("EFC") and Energy Co-Opportunity, Inc. ("ECO")
both of 2201 Cooperative Way, Herndon, VA 20171. These parties are referred to
herein singularly as "Party" and collectively as "Parties." Defined terms used,
but not otherwise defined herein, shall have the respective meanings set forth
in the Second Amended and Restated Fuel Cell Product Operating Agreement, dated
April 10, 2002, among the Parties (the "Operating Agreement").


                                    RECITALS

WHEREAS: On the date hereof, the Parties have entered into the Operating
Agreement to, among other things, further encourage the marketing of H Power's
Fuel Cell Products, to provide the Parties with additional marketing and
distribution opportunities, and to explore other products and services offered
by H Power including new fuel cell products and applications; and

WHEREAS: the Parties desire to mutually encourage the development, marketing and
selling of H Power's Fuel Cell Products to electric Cooperatives and others,
and;

WHEREAS: EFC has specific sales and marketing expertise in Distributed
Generation (DG) equipment and related applications that is transferable to Fuel
Cell Products sales and marketing, and;

WHEREAS: H Power desires to secure EFC's expertise in sales, marketing and other
areas to help enhance the commercialization of its Fuel Cell Products.

NOW, THEREFORE, in consideration of the promises herein and other valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the
Parties hereby agree as follows:


      1.    FUEL CELL SALES AND MARKETING SUPPORT.

            a.    EFC will work with H Power to identify and create sales
                  opportunities for Fuel Cell Products, including H Power's EPAC
                  series. This will include identification of potential markets
                  and applications, channels of distribution, and similar
                  activities.

            b.    EFC will continue to actively promote the Fuel Cell Power
                  System for residential markets and will participate in
                  evaluation studies and placement of test units to finalize the
                  development of the Cooperative design and to enter other
                  markets.

            c.    EFC's Services shall include:

----------
Certain portions of this exhibit have been omitted pursuant to a request for
confidential treatment. The omitted materials have been filed separately with
the Securities and Exchange Commission.


                                  Page 1 of 7

<PAGE>

                  i.    EFC, in collaboration with others, will provide H Power
                        with a report on "typical" electric utility approaches
                        for engineering review of customer requested DG grid
                        interconnection to help H Power better understand
                        interconnection requirements. The report will include
                        the typical utility steps that must be taken to properly
                        account for site-specific concerns and will address the
                        typical technical and procedural requirements of
                        interconnection standards.

                  ii.   EFC shall work with H Power, and both Parties will use
                        reasonable commercial efforts to jointly identify and
                        secure $3.0 million in grants and/or other funds in the
                        eighteen month period following the Effective Date to
                        support the Fuel Cell Product test and development
                        programs, which may include potential funding for
                        related technologies.

                  iii.  EFC shall organize and sponsor a national distributed
                        generation seminar in April 2002 that will include
                        invitations to a broad spectrum of non-Cooperative and
                        Cooperative utilities and customers. H Power will be a
                        featured presenter at the seminar.

                  iv.   EFC shall create new marketing and distribution channels
                        for Fuel Cell Products through the electric Cooperatives
                        and others by encouraging customers to actively seek new
                        applications for Fuel Cell Products that will expand
                        future sales opportunities.

                  v.    EFC shall staff and display H Power products and
                        services at two electric Cooperative industry or related
                        trade shows in 2002 and 2003, one of which shall include
                        the NRECA Annual Meeting in both years. H Power will
                        provide all Fuel Cell equipment for the displays, and
                        EFC shall provide the display space, personnel and
                        display platforms for H Power for a cost not to exceed
                        $50,000 per show.

                  vi.   EFC shall identify, assess and evaluate future and
                        existing Fuel Cell Product markets, fuel cell customer
                        needs, additional product development opportunities and
                        applications and similar items as follows. EFC shall be
                        responsible for developing and managing a structured
                        focus group program consisting of two different
                        participant interview sessions for the purpose of
                        establishing new sales opportunities for $15 million of
                        new revenue from "Other Fuel Cells". EFC shall be
                        responsible for securing participants for the program.

                  vii.  EFC shall develop marketing and promotion materials for
                        H Power, identify marketing issues for H Power and
                        develop market penetration and market share strategies
                        for H Power.


                                  Page 2 of 7

<PAGE>

                  viii. EFC's Project Manager for this agreement will work with
                        national Cooperative organizations to secure display and
                        educational opportunities for H Power, and will
                        coordinate any display set ups or material hand-outs
                        needed for these opportunities with H Power.

            2.    PROJECT MANAGER. EFC's Project Manager for this Agreement
                  shall be Robert Gibson. The Project Manager shall, in addition
                  to the other duties prescribed in this Agreement, develop a
                  travel budget for this Agreement, working closely with H
                  Power. During the term of this Agreement, Mr. Gibson and other
                  EFC personnel shall integrate the H Power activities described
                  herein into their EFC workload, and shall be responsible for
                  establishing work priorities, schedules and completion of work
                  requests. Mr. Gibson shall inform both EFC and H Power when
                  potential or real conflicts of activities or scheduling exist,
                  and the Parties shall mutually resolve such conflicts for Mr.
                  Gibson. During the term of this Agreement, H Power shall not
                  solicit any EFC staff for employment.

                  H Power and EFC shall agree to prepare travel (including
                  transportation, lodging, meals, and entertainment) and other
                  budgets from time to time to carry out the purposes of this
                  Agreement. In addition to the payments made under Attachment A
                  of this Agreement, any travel to be performed at H Power's
                  request that exceeds $1,000 per month shall be paid for by H
                  Power, except for the travel expenses in conjunction with the
                  planned EFC meetings described in Sections 1.c. iii and 1.c.v.
                  above or as may otherwise be agreed to in writing by the
                  Parties. EFC shall provide satisfactory documentation for such
                  expenses in such detail as H Power may reasonably request.

            3.    LIMITATIONS. IN NO EVENT SHALL THE PARTIES (INCLUDING THEIR
                  OFFICERS, DIRECTORS, EMPLOYEES, AGENTS AND ATTORNEYS) BE
                  LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL
                  DAMAGES (INCLUDING BUT NOT LIMITED TO LOST PROFITS) IN THE
                  PERFORMANCE OF THEIR DUTIES UNDER THIS AGREEMENT, EVEN IF THEY
                  HAVE NOTICE OF THE POSSIBILTY OF SUCH DAMAGES, EXCEPT FOR (I)
                  ANY PRODUCT LIABILITY, (II) ANY INFRINGEMENT OF INTELLECTUAL
                  PROPERTY RIGHTS, AND (III) OTHER DAMAGES CAUSED BY NEGLIGENCE
                  OR WILLFUL MISCONDUCT OF THE PARTIES OR THEIR EMPLOYEE(S).
                  HOWEVER, NOTHING HEREIN IS TO LIMIT OR CHANGE THE PROVISIONS
                  OF THE EFC-H POWER OPERATING AGREEMENT (AS AMENDED FROM TIME
                  TO TIME).

            4.    PAYMENT FOR SALES AND MARKETING SERVICES. Subject to Sections
                  5, 6, and 7 hereof, in exchange for the above services, H
                  Power will pay EFC up to $1.5 million per the schedule in
                  Attachment A hereto. EFC may invoice H Power monthly or
                  quarterly for its services. Payment of invoices will be due
                  and payable 15 days after receipt by H Power. In addition, H
                  Power agrees to pay EFC per the Schedule in Attachment A of
                  this Agreement an amount not to


                                  Page 3 of 7

<PAGE>

                  exceed $50,000 for its participation in each trade show
                  referenced in Section 1.c.v.

            5.    AFFIRMATIVE AND NEGATIVE COVENANTS. Notwithstanding anything
                  contained in this Agreement to the contrary, this Agreement is
                  subject to certain binding Affirmative and Negative Covenants
                  ("Covenants") contained in a "Memorandum of Agreement" entered
                  into by the Parties on the date of this Agreement.

            6.    NO MATERIAL ADVERSE CHANGE. Notwithstanding anything contained
                  in this Agreement to the contrary, H Power shall have no
                  obligation to make payments to EFC during the Term hereof, if
                  there has been a "Material Adverse Change." For the purposes
                  of this Agreement, a Material Adverse Change shall only be
                  defined as a material violation of Sections 2, 3, 4, or 5 of
                  the Memorandum of Agreement.

            7.    FAILURE TO COMPLY. Notwithstanding anything contained in this
                  Agreement to the contrary, upon ECO's and/or EFC's breach of
                  any of the Affirmative or Negative Covenants set forth in the
                  Memorandum of Agreement, H Power shall have the unilateral
                  right to suspend payment of any monies due to EFC hereunder
                  (including those set forth on Attachment A hereto) until such
                  time that ECO and/or EFC cures such breach to H Power's
                  satisfaction.

            8.    TERM. This Agreement shall terminate upon: i) the completion
                  of EFC's and ECO's duties referred to herein; or ii) the
                  written agreement of the Parties.

            9.    DISPUTES. The Parties agree that any and all controversies or
                  claims arising out of or relating to this Agreement, or any
                  alleged breach hereof, shall be resolved by binding
                  arbitration as prescribed herein, upon 30 days' written notice
                  to the other Party. In that event, the Parties each Party
                  shall select one (1) arbitrator and those shall select a
                  third. The three (3) arbitrators will conduct the arbitration
                  under the then current rules of the American Arbitration
                  Association ("AAA"), unless otherwise provided herein. The
                  arbitrator(s) will be selected in accordance with AAA
                  procedures from a list of qualified arbitrators maintained by
                  AAA. The arbitration will be conducted in Washington, D.C. and
                  all expedited procedures prescribed under AAA rules will
                  apply. Unless the Parties otherwise agree, the proceedings
                  will be completed within forty-five (45) days of the Parties'
                  receipt of notice of arbitration. Each Party will bear its own
                  costs and attorney's fees.

            10.   MUTUAL COOPERATION. The Parties agree to take such other
                  actions and execute such other documents as shall be necessary
                  to carry out the provisions of this Agreement.

            11.   ENTIRE AGREEMENT. With the exception of the Operating
                  Agreement and the Memorandum of Agreement, this Agreement
                  (including any Schedules and Exhibits attached hereto)
                  constitutes the entire agreement among the Parties with
                  respect to the subject matter hereof and supercedes all prior
                  and contemporaneous agreements and undertakings, written or
                  oral, of any nature whatsoever of the Parties hereto with
                  respect to the subject matter hereof.


                                  Page 4 of 7

<PAGE>

            12.   NOTICES. All notices and other communications hereunder shall
                  be in writing and shall be deemed to have been duly given when
                  delivered in person, by telecopy (with confirmation of
                  transmission), by express or overnight mail delivered by a
                  nationally recognized air courier (delivery charges prepaid),
                  or by registered or certified mail (postage prepaid, return
                  receipt requested) to the Parties at their respective
                  addresses set forth in the preamble of this Agreement or to
                  such other address as the Party to whom notice is given may
                  have previously furnished to the other Parties in writing in
                  the manner set forth above. Any notice or communication
                  delivered in person shall be deemed effective on delivery. Any
                  notice or communication sent by telecopy or by air courier
                  shall be deemed effective on the first business day at the
                  place at which such notice or communication is received
                  following the day on which such notice or communication was
                  sent. Any notice or communication sent by registered or
                  certified mail shall be deemed effective on the fifth business
                  day at the place from which such notice or communication was
                  mailed following the day on which such notice or communication
                  was mailed.

            13.   PARTY'S RELATIONSHIP. Neither Party by this Agreement makes
                  the other Party its legal representative or agent. Neither
                  Party shall assign this Agreement to any other third party
                  without the other Party's prior written permission, except
                  that ECO and ECO Fuel Cells may assign it to a Cooperative
                  Member.

            14.   NO RIGHTS IN THIRD PARTIES. Nothing contained in this
                  Agreement shall be construed as giving rise to any rights to
                  enforce its provisions to any person or entity not a Party to
                  this Agreement under any legal theory.

            15.   COUNTERPARTS. This Agreement may be executed in any number of
                  counterparts, each of which shall be deemed to be an original
                  as against any Party whose signature appears thereon, and all
                  of which shall together constitute one and the same
                  instrument. This Agreement shall become binding when one or
                  more counterparts hereof, individually or taken together,
                  shall bear the signatures of all the Parties hereon as
                  signatories.

            16.   SEVERABILITY. If any provision of this Agreement for any
                  reason shall be held to be illegal, invalid or unenforceable,
                  such illegality shall not affect any other provision of this
                  Agreement, but this Agreement shall be construed as if such
                  illegal, invalid or unenforceable provision had never been
                  included herein.

         IN WITNESS WHEREOF the undersigned Parties hereby execute this
Agreement.


         H POWER CORP.                      H POWER ENTERPRISES OF CANADA, INC.

         /s/ William L. Zang                H. Frank Gibbard
         -----------------------------      -----------------------------------



                                  Page 5 of 7

<PAGE>


      ECO FUEL CELLS, LLC                     ENERGY CO-OPPORTUNITY, INC.

      /s/ William C. Cetti                    /s/ William C. Cetti
      ------------------------------------    ---------------------------------
      William C. Cetti, President & CEO       William C. Cetti, President & CEO





                                  Page 6 of 7

<PAGE>

                                  ATTACHMENT A

                     SALES AND MARKETING SERVICES AGREEMENT
                                     BETWEEN
                 ECO FUEL CELLS, LLC, ENERGY CO-OPPORTUNITY INC.
                                       AND
                                  H POWER CORP.

                     ATTACHMENT OF H POWER'S PAYMENTS TO EFC


Subject to the terms and conditions set forth in the Agreement, H Power shall
make the following payments to EFC:


<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------------------
                                   April-2002  Qtr 2-2002 Qtr 3-2002  Qtr 4-2002  SubTotal   Qtr 1-2003   Qtr 2-2003  Qtr 3-2003
==================================================================================================================================
<S>                                <C>         <C>        <C>         <C>         <C>        <C>          <C>         <C>
Sales and Marketing Services           [*]        [*]         [*]        [*]         [*]         [*]         [*]         [*]
Trade Show Displays and Staffing       [*]        [*]         [*]        [*]         [*]         [*]         [*]         [*]
==================================================================================================================================
                              TOTAL    [*]        [*]         [*]        [*]         [*]         [*]         [*]         [*]
----------------------------------------------------------------------------------------------------------------------------------
</TABLE>


<TABLE>
<CAPTION>
-------------------------------------------------------------
                                    Qtr 4-2003     Totals
=============================================================
<S>                                 <C>            <C>
Sales and Marketing Services           [*]          [*]
Trade Show Displays and Staffing       [*]          [*]
=============================================================
                              TOTAL    [*]       $1,700,000
-------------------------------------------------------------
</TABLE>

----
* Confidential





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