<PAGE>

                                                                   EXHIBIT 10.40

CONFIDENTIAL INFORMATION HAS BEEN OMITTED PURSUANT TO RULE 24b-2 UNDER THE
SECURITIES EXCHANGE ACT AND HAS BEEN FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION. THE LOCATIONS OF THE OMITTED INFORMATION HAVE BEEN
INDICATED WITH A "[x]."

                   Amendment to PP-GEFS Distributor Agreement

                                  CONFIDENTIAL


Amendment to the Distributor Agreement between GE Fuel Cell Systems, L.L.C. and
                   Plug Power, L.L.C., dated February 2, 1999


                                 July ___, 2000



     This Amendment to the Distributor Agreement (the "Amendment") dated
February 2, 1999 is made and entered into as of this ____ day of July, 2000, by
GE FUEL CELL SYSTEMS, L.L.C., a Delaware limited liability company located at
968 Albany-Shaker Road, Building 1, Latham, New York 12110 (hereinafter referred
to as "GEFCS" or "DISTRIBUTOR"), and PLUG POWER, INC., a Delaware corporation,
successor-in-interest to Plug Power, L.L.C., located at 968 Albany-Shaker Road,
Latham, New York 12110 (hereinafter referred to as "PP" or "SUPPLIER").  GEFCS
and PP are individually referred to herein as a "Party" and collectively as the
"Parties".

     WHEREAS, DISTRIBUTOR and SUPPLIER entered into a Distributor Agreement
dated February 2, 1999 (the "Agreement"), in order to set forth, among other
items, DISTRIBUTOR's obligation to market, sell, and provide services for
"Product" and "Pre-Commercial Units," both of which are defined in the
Agreement;

     WHEREAS, GEFCS and other General Electric Company affiliates have entered
into various agreements with PP related to the Agreement, including, without
limitation, the letter agreement from GE Power Systems to PP dated February 3,
1999, and the Agreement between PP, GE On-Site Power, Inc., and GEFCS dated
August 27, 1999 ("August 27 Agreement"); and

     WHEREAS, DISTRIBUTOR and SUPPLIER now desire to further amend the Agreement
to reflect certain changes, including the revision of the Product and Pre-
Commercial Unit performance specifications and delivery schedules and the
establishment of a process by which GEFCS determines that the Product and Pre-
Commercial Units meet the applicable specifications, as set forth below;

     NOW, THEREFORE, in consideration of the premises and of the mutual
covenants and agreements herein contained, the mutual benefits to be derived
herefrom, and other good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, the Parties hereto agree as follows:

1.  Product and Pre-Commercial Unit ("PCU") Performance Specifications

     The sections entitled "Pre-Commercial Unit Performance Specifications" and
     "Product ("Commercial Unit") Performance Specifications" set forth in
     Schedule B of the Agreement are replaced in their entirety with Schedule A
     of the Amendment. Schedule A includes, among other things, information
     regarding a GEFCS acceptance testing process for PCUs and CUs, by which
     GEFCS will determine, in its sole discretion, whether the PCUs and CUs meet
     the agreed upon specifications, and GEFCS notifies PP, if applicable, that
     the product is "available for sale by GEFCS".

     The following sentence is added after the last sentence of Section 1.9 of
     the Agreement:

                                       1
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

         The term "Pre-Commercial Unit," when used herein, shall include the
         Pre-Commercial Unit (PCU) versions of Residential Unit RU1, RU2, RU3,
         and RU4.

     The following sentence is added after the last sentence of Section 1.11 of
     the Agreement:

         The term "Product," when used herein, shall include the Commercial Unit
         (CU) versions of Residential Unit RU1, RU2, RU3, and RU4.

     The following is added after Section 1.16 of the Agreement:

         1.17 RU1, RU2, RU3, and RU4. The terms "RU1", "RU2", "RU3", and "RU4",
         when used herein, shall mean "Residential Unit" versions 1 through 4 of
         Pre-Commercial Units and Commercial Units, with associated performance
         levels as set forth in Schedule A of the Amendment.

         1.18 Amendment. The term "Amendment", when used herein, shall mean the
         Amendment to this Agreement dated July ____, 2000.

2.  GEFCS PRODUCT PURCHASE GOALS

     DISTRIBUTOR's Global Sales Commitments and Major Market Sales Commitments,
     as defined in the Agreement, are deleted.

     Section 5.2 of the Agreement is deleted in its entirety and replaced with
     the following:

         5.2 Product Purchase Goals. DISTRIBUTOR will use commercially
         reasonable efforts, subject to delivery of the PCUs and CUs deemed by
         GEFCS to be available for sale in accordance with the delivery schedule
         set forth in Paragraph 10 of the Amendment, to achieve the purchase
         goals set forth below by December 31, 2004.


                                          GEFCS Purchase Goals


                                               PCUS AND CUS (COMBINED)
                                               -----------------------
                  RU1                                 [X]
            RU2 AND RU3 (COMBINED)                    [X]
                  RU4                                 [X]

          In the event that PP does not deliver to GEFCS PCUs and CUs a) deemed
          by GEFCS to be available for sale and b) in accordance with the
          delivery schedule set forth in Paragraph 10 of the Amendment, GEFCS
          and PP shall mutually agree on revised purchase goals, provided that
          if GEFCS and PP are unable to agree on such revised purchase goals, no
          product purchase goals shall be applicable.

     Section 5.5 of the Agreement is deleted in its entirety and replaced with
     the following:

          5.5  [Section intentionally left blank]

                                       2
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

     The phrase "in accordance with Schedule D" is deleted from
     Section 4.3(a) of the Agreement.

     Schedule D of the Agreement is deleted in its entirety and replaced with
     the following:

                                   SCHEDULE D


                    [This Schedule intentionally left blank]

3.  PCU and Product Warranties

     Section 7 of the Terms and Conditions of Purchase/Sale set forth in
     Schedule B of the Agreement is revised as follows:


     a.  The second sentence of subsection (c) is deleted and replaced by the
         following:

         For Products purchased under this Agreement during the period ending
         December 31, 2004, the foregoing warranties shall apply for a period
         that is the greater of (a) [X] from the date of installation, or (b)
         [X] from the date of SUPPLIER's invoice to GEFCS following delivery of
         the Product and associated components. This Product warranty period
         shall apply to all of the CU versions of RU1, RU2, RU3, and RU4.

         For Products purchased under this Agreement beginning January 1, 2005,
         the foregoing warranties shall apply for a period that is the greater
         of (a) [X] from the date of installation, or (b) [X] from the date of
         SUPPLIER's invoice to GEFCS following delivery of the Product and
         associated components. This Product warranty period shall apply to all
         of the CU versions of RU1, RU2, RU3, and RU4.

     b.  The third sentence of subsection (c) is deleted and replaced by the
         following:

         For Pre-Commercial Units purchased under this Agreement, the foregoing
         warranties shall apply for a period that is the greater of (a) [X] from
         the date of installation or [X] from the date of SUPPLIER's invoice to
         DISTRIBUTOR following delivery of the PCU and associated components to
         DISTRIBUTOR, whichever is less, and (b) the period of time until a CU
         of the same RU version as the Pre-Commercial Unit is available for sale
         by DISTRIBUTOR (as determined by DISTRIBUTOR pursuant to the PCU and
         Product acceptance criteria in Schedule A of the Amendment). This PCU
         warranty period shall apply to all of the PCU versions of RU1, RU2,
         RU3, and RU4.

     c.  The fourth paragraph beginning with the sentence, "For Products,
         SUPPLIER will provide DISTRIBUTOR with the option of purchasing an
         extension to the initial warranty period" is deleted.

4.  CU RU1 Replacement

     The following paragraph shall be added after the third paragraph of Section
     7 of the Terms and Conditions of Purchase/Sale set forth in Schedule B of
     the Agreement:

                                       3
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

          PP, at its sole expense, will replace each CU RU1 with a CU RU4 that
          is deemed available for sale by GEFCS. PP will complete each
          replacement within [X] of installation of each RU1.  Replacement will
          not extend the Product warranty period beyond the warranty period set
          forth in Paragraph 3(a) of the Amendment, provided, however, that in
          no event shall the warranty period for the replacement CU RU4 apply
          for a period less than [X] beginning on the date of installation of
          such CU RU4.  In the event that PP is unable to replace any RU1 within
          [X] of installation [X], then PP agrees, at GEFCS's sole option, to
          either (a) refund to GEFCS, or such other party as designated by
          GEFCS, all [X] incurred by GEFCS, its distributors, or end-users in
          connection with the failure to replace the RU1, including without
          limitation the total [X] price paid by the then-current owner of the
          RU1 for such RU1 and all installation, removal, and shipping costs of
          the RU1, or (b) pay to the then-current owner of the RU1 [X] until
          such time that a replacement RU4 is available, at which time PP, at
          PP's sole expense, will replace such CU RU1 with a CU RU4.

5.  PCU and CU Prices

     Section 3.3(a) of the Agreement is deleted in its entirety and replaced
     with the following:

          3.3(a)  The prices charged to DISTRIBUTOR for all PCUs and CUs
          purchased hereunder shall be the lower of (i) the applicable prices
          set forth in the Amendment, including all Schedules thereto, and (ii)
          the lowest prices charged by SUPPLIER to any other person or entity
          for the same such PCU or CU in similar quantities during the [X]
          preceding DISTRIBUTOR's purchase.

     The following is added after Section 3.3(d) of the Agreement:

          (e) For Products other than the PCU and CU versions of RU1, RU2, RU3,
          and RU4 offered for sale by SUPPLIER to DISTRIBUTOR,  SUPPLIER's
          prices to DISTRIBUTOR (i.e., transfer prices) will be as mutually
          agreed in good faith between the Parties.  In the event that the
          Parties can not agree on transfer prices applicable to such additional
          Products, then the Parties shall commence nonbinding mediation to
          establish the transfer prices, which mediation shall be facilitated by
          a mediator selected by the Parties. In the event that the Parties are
          not able to agree on transfer prices during the ninety (90) day period
          following the commencement of mediation, either Party may submit to
          arbitration the issue of establishing the transfer prices.  Such issue
          shall be determined by one arbitrator in accordance with the
          Commercial Arbitration Rules of the American Arbitration Association
          (AAA) as then in effect and except as modified by explicit provision
          in this Article.

          The Parties may mutually agree to extend the time periods provided for
          in the AAA Arbitration Rules.  Unless the Parties agree otherwise or
          the arbitral tribunal directs otherwise, the locale of the arbitration
          will be Latham, New York.  At its discretion, the arbitral tribunal
          may hold pre-hearing conferences or adopt other procedures (including
          reasonable discovery).  The right to reasonable examination of
          opposing witnesses in oral hearing will not be denied.  The English
          language shall be used in the arbitral proceedings.  Each Party will
          bear its own costs of presenting or defending its position in the
          arbitration.

                                       4
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

          (f) DISTRIBUTOR will have the right to audit SUPPLIER's financial
          records to the extent necessary to confirm SUPPLIER's calculation of
          actual [X].

     The first sentence of Section 6.9 of the Agreement is deleted in its
     entirety and replaced with the following:

          Prices to DISTRIBUTOR for PCU, Product, and additional Product
          replacement parts will be as mutually agreed by the Parties; provided
          however that in no case will the prices exceed SUPPLIER's actual [X].
          All major components replaced by SUPPLIER pursuant to the warranty
          provisions herein will be returned to SUPPLIER at SUPPLIER's request
          and at SUPPLIER's expense.

6.  PCU AND CU PRICES (THROUGH 12/31/2004)

     Schedule C of the Agreement is deleted in its entirety and replaced by the
     following:


                                      PCU and Product Prices

                         PCU PRICE TO GEFCS       CU PRICE TO GEFCS
                             ($/UNIT)                 ($/UNIT)
                         ------------------       -----------------
              RU1              $[X]                     $[X]
              RU2               [X]                      [X]
              RU3               [X]                      [X]
              RU4               [X]                      [X]

          Prices shown are for the PCUs and CUs as specified in Schedule A of
          the Amendment and deemed available for sale by GEFCS. Prices for the
          PCUs and CUs as shown are firm (i.e., not subject to change) and will
          apply during the period beginning on the execution date of the
          Amendment and ending on December 31, 2004.

          Provided that SUPPLIER meets the PCU RU1 delivery date set forth in
          Paragraph 10 of the Amendment, DISTRIBUTOR will, on or before July 1,
          2001, on a monthly basis provide SUPPLIER with a 12-month rolling
          forecast of DISTRIBUTOR's monthly purchases.  Each of the first [X] of
          DISTRIBUTOR's forecast will be a firm order.  DISTRIBUTOR's forecast
          for the final [X] of the forecast period is for SUPPLIER's planning
          purposes only.  DISTRIBUTOR, at its sole discretion, may change the
          monthly purchase forecast in any month in the final [X] forecast
          period by any amount.  In the event that SUPPLIER fails to meet the
          PCU RU1 delivery date set forth in Paragraph 10 of the Amendment,
          DISTRIBUTOR will begin providing SUPPLIER with 12-month rolling
          forecasts 3 months after the date that SUPPLIER first makes PCU RU1
          available for sale by DISTRIBUTOR.

          Any Products for which DISTRIBUTOR has issued a purchase order, but is
          unable to sell, may be held in SUPPLIER's inventory at the request of

                                       5
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

          DISTRIBUTOR.  Electing to have SUPPLIER hold DISTRIBUTOR's inventory
          does not relieve DISTRIBUTOR of its obligations under the purchase
          order.  DISTRIBUTOR will reimburse SUPPLIER for its fully loaded
          inventory carrying cost, including warehouse expenses, interest, and
          any inventory carrying cost charged to SUPPLIER by SUPPLIER's vendors
          as a direct result of DISTRIBUTOR's request for SUPPLIER to hold
          inventory.  On or before April 1, 2001, SUPPLIER will provide
          DISTRIBUTOR with a firm price for the monthly inventory carrying
          charge for 2001.  On or before each August 1 thereafter, SUPPLIER will
          provide DISTRIBUTOR with a firm price for the monthly inventory
          carrying charge for the upcoming year.

          The last sentence of Section 6.6 of the Agreement is deleted in its
          entirety.

7. PCU and CU Prices (1/1/2005 - 3/4/2009)

     The last two sentences of Section 5.1 of the August 27 Agreement are
     deleted in their entirety and replaced with the following:

          For the period January 1, 2005-December 31, 2006, the CU price to be
          paid by DISTRIBUTOR (the "Transfer Price") will be as set forth in
          Schedule B of the Amendment to the Distributor Agreement dated July
          31, 2000 ("Amendment").  In the event that (a) SUPPLIER's actual [X]
          (defined as [X] (defined as [X]), provided that manufacturing overhead
          may not exceed [X] of the sum of direct material costs plus direct
          labor costs), as set forth in Column B of Schedule B of the Amendment
          for the applicable production lot (based on total PP cumulative
          production volume for all customers) exceed the Transfer Price for
          such lot, and/or (b) the Transfer Price for such lot exceeds the [X],
          then the Transfer Price for such lot will be set at [X].  When used in
          the Amendment, [X] shall mean then prevailing average, global retail
          price for a PEM Fuel Cell-Powered Generator Set (as defined in Section
          1.7 of the Agreement) of comparable features (including kW output,
          cogeneration capability, efficiency, life, and lifecycle cost) to the
          Product.

          The Parties will establish a mutually agreed upon mechanism for
          establishing the [X] no later than July 1, 2003; provided however that
          if the Parties cannot reach agreement on the mechanism, then the
          Parties shall commence nonbinding mediation to establish the [X],
          which mediation shall be facilitated by a mediator selected by the
          Parties. In the event that the Parties are not able to agree on a [X]
          during the ninety (90) day period following the commencement of
          mediation, either Party may submit to arbitration the issue of
          establishing the [X]. Such issue shall be determined by one arbitrator
          in accordance with the Commercial Arbitration Rules of the American
          Arbitration Association (AAA) as then in effect and except as modified
          by explicit provision in this Article.

          The Parties may mutually agree to extend the time periods provided for
          in the AAA Arbitration Rules.  Unless the Parties agree otherwise or
          the arbitral tribunal directs otherwise, the locale of the arbitration
          will be Latham, New York.  At its discretion, the arbitral tribunal
          may hold pre-hearing conferences or adopt other procedures (including
          reasonable discovery).  The right to

                                       6
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

          reasonable examination of opposing witnesses in oral hearing will not
          be denied. The English language shall be used in the arbitral
          proceedings. Each Party will bear its own costs of presenting or
          defending its position in the arbitration.

          For the period January 1, 2007-March 4, 2009, the Transfer Price will
          be as set forth in Schedule B of the Amendment. In the event that (a)
          SUPPLIER's [X] for the applicable production lot exceed the Transfer
          Price for such lot, and/or (b) the Transfer Price for such lot exceeds
          the [X], then the Transfer Price for such lot will be set at the [X].

          SUPPLIER's Direct Costs and the Transfer Prices, as set forth Schedule
          B of the Amendment, are expressed in nominal (i.e., year 2000) dollars
          and will be adjusted on each January 1st, beginning January 1, 2005,
          for changes in the Producer Price Index ("PPI") from the prior period
          (e.g., on January 1, 2005, the Direct Costs and Transfer Prices will
          be adjusted for changes in the PPI from the execution date of the
          Amendment to January 1, 2005.  On January 1, 2006, the Direct Costs
          and Transfer Prices will be adjusted for changes in the PPI from
          January 1, 2005 to January 1, 2006).

8.  OPTION TO EXTEND TERM/CU PRICES (3/5/2009-12/31/2014)

     The following sentence is added after the first sentence of Section 5.1 of
     the August 27 Agreement:

          GEFCS shall have the option of extending the termination date of the
          Distributor Agreement from March 4, 2009 through December 31, 2014,
          provided that such option will expire on July 31, 2008, unless
          exercised by GEFCS on or prior to that date.  If GEFCS elects to
          extend the Distributor Agreement, the payment terms and purchase goals
          in existence at the end of the current (i.e., March 4, 2009) term will
          apply for the [X] (i.e., [X] through [X]).

     The following is added as the last paragraph of Section 5.1 of the August
     27 Agreement:

          In order to supplement the Distributor Agreement with Product transfer
          prices applicable to the period March 5, 2009-December 31, 2014, GEFCS
          and PP agree to begin discussions of such prices not later than
          January 1, 2008, and engage in negotiations to conclude such
          discussion by March 31, 2008. In the event GEFCS and PP fail to
          mutually agree on transfer prices, the prices shall be set at [X].

9. PAYMENT TERMS

     The fifth sentence of Section 2 of the Terms and Conditions of
     Purchase/Sale in Schedule B of the Agreement is deleted and replaced by the
     following two sentences:

          Unless otherwise agreed between SUPPLIER and DISTRIBUTOR, payments
          shall become due [X] days from DISTRIBUTOR's receipt of SUPPLIER's
          invoice. For any of DISTRIBUTOR's orders where SUPPLIER is more than
          one month late in delivery, DISTRIBUTOR, at its sole option, may
          cancel any or all of such order.

                                       7
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

10. PCU AND PRODUCT DELIVERY SCHEDULE

     The following is added after Section 6.10 of the Agreement:

          6.11  Delivery Schedule. SUPPLIER shall use best efforts to deliver
          PCUs and CUs to DISTRIBUTOR according to the following schedule:

                          PCU AND CU DELIVERY SCHEDULE

                 PCUS AVAILABLE TO                CUS AVAILABLE TO
                    DISTRIBUTOR                      DISTRIBUTOR
                 -----------------          ------------------------------
     RU1               [X]                              [X]
     RU2               [X]                              [X]
     RU3               [X]                              [X]
     RU4               [X]                              [X]

     Section 6.7(a) of the Agreement is deleted in its entirety and replaced
     with the following:

          SUPPLIER will use best efforts to maintain a minimum annual Product
          production capacity necessary to meet DISTRIBUTOR's CU purchase goals
          as shown in Paragraph 2 of the Amendment. To the extent SUPPLIER
          experiences capacity constraints that limit its ability to deliver
          PCUs or Products to DISTRIBUTOR, PP will allocate the PCUs and/or
          Products to GEFCS and to other parties that have placed firm orders on
          a pro rata basis as a proportion of their firm orders.

     Sections 6.7(b) and 6.7(c) of the Agreement are deleted in their entirety.

     The second sentence of Section 3 (Delivery and Passage of Title) of the
     Terms and Conditions of Purchase/Sale of Schedule B of the Agreement is
     deleted in its entirety and replaced with the following two paragraphs:

          If SUPPLIER fails to deliver the PCU and CU versions of RU1, RU2, RU3,
          and/or RU4 in accordance with the delivery schedule set forth in
          Paragraph 10 of the Amendment or such units are delivered in
          accordance with the delivery schedule but are deemed by GEFCS not to
          be available for sale, then the unit price to DISTRIBUTOR for each
          unit deemed available for sale, in addition to the remedies available
          to DISTRIBUTOR elsewhere under the Agreement and the Amendment, will
          be reduced by [X] for each month of delay (e.g., CU RU1 delivery in
          [X], represents a 1 month delay) after the first two months of delay
          (i.e., SUPPLIER has a 2 month grace period); provided that the unit
          price to DISTRIBUTOR will not be reduced by more than [X], and the
          price reduction will apply only for the first [X] after the delayed
          PCU and/or CU version becomes available to DISTRIBUTOR (e.g., if
          SUPPLIER first makes PCU RU3 available in [X], DISTRIBUTOR's price for
          PCU RU3 for the period [X] to [X] will be $[X]/unit, returning to
          $[X]/unit beginning [X]).

                                       8
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

          If SUPPLIER delivers the PCU and CU versions of RU1, RU2, RU3, and/or
          RU4 prior to the delivery schedule set forth in Paragraph 10 of the
          Amendment and such units are deemed by GEFCS to be available for sale,
          then the unit price to DISTRIBUTOR for each unit deemed available for
          sale will be increased by [X] for each month of acceleration; provided
          that the unit price to DISTRIBUTOR will not be increased by more than
          [X], and the price increase will apply only for the first [X] after
          the accelerated PCU and/or CU version becomes available to DISTRIBUTOR
          (e.g., if SUPPLIER first makes PCU RU3 available in [X], DISTRIBUTOR's
          price for PCU RU3 for the period [X] to [X] will be $[X]/unit,
          returning to $[X]/unit beginning [X]).

11. TERMINATION FOR CAUSE

     The following paragraph is added after the first sentence of Section 4.2 of
     the Agreement:

          This Agreement may be terminated by GEFCS prior to expiration of the
          initial five (5) year term or any renewal term hereof by furnishing
          prior written notice to PP in the event PP should fail to perform any
          of its obligations set forth in the Amendment, including its
          obligations in the Schedules thereto, provided PP shall fail to remedy
          any such nonperformance within 120 days after receiving written demand
          therefor.

12. COMPETING PRODUCTS

     The following paragraphs revise the letter agreement between GE Power
     Systems and Plug Power, L.L.C., dated February 3, 1999:

          In the event that PP does not offer PEM fuel cell-powered generator
          sets capable of producing maximum continuous output of (a) [X]),
          and/or (b) [X]), that are (i) suitable for residential, commercial,
          and/or industrial stationary power applications outlined in the
          paragraph 1 of Schedule A-1 of the Agreement, and (ii) capable of
          running on natural gas and LPG fuel, and (iii) capable of producing
          IEEE 519-quality AC electricity at [X] and [X] Hz, and (iv) available
          for commercial sale by GEFCS, and another manufacturer has a PEM fuel
          cell-powered generator set available in the [X] and/or [X] kW size
          range(s) available for commercial sale by GEFCS ("Competing Product"),
          then upon one hundred and twenty (120) days written notice to PP,
          GEFCS or a GEFCS affiliate may, at its sole option, become a
          distributor for such non-PP PEM fuel cell, provided that PP does not
          produce a competitive product in that size range within the one
          hundred and twenty (120) day period.

          GEFCS will provide PP with (a) notice of the availability of a
          Competing Product at the earliest feasible date, and (b) periodic
          marketing updates that address, among other matters, distributor and
          end-user feedback on the Products, GEFCS's marketing plans, and the
          demand for various sized products.

          In the event that GEFCS or a GEFCS affiliate elects to distribute a
          non-PP PEM fuel cell-powered generator set in the [X] kW size range
          ("Non-PP [X] kW PEM Gen Set"), then PP may name additional
          distributors, on either an exclusive or

                                       9
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

          non-exclusive basis, for PP product in the [X] kW size range ("PP [X]
          kW PEM Gen Set"), provided that PP shall notify GEFCS when PP deems,
          in its sole discretion, that such PP [X] kW PEM Gen Set is
          commercially available and GE may elect during the sixty (60) day
          period following such notice to discontinue distribution of the Non-PP
          [X] kW PEM Gen Set and become the exclusive distributor of the PP [X]
          kW PEM Gen Set.

          In the event that GEFCS or a GEFCS affiliate elects to distribute a
          non-PP PEM fuel cell-powered generator set in the [X] kW size range
          ("Non-PP [X] kW PEM Gen Set"), then PP may name additional
          distributors, on either an exclusive or non-exclusive basis, for PP
          product in the [X] kW size range ("PP [X] kW PEM Gen Set"), provided
          that PP shall notify GEFCS when PP deems, in its sole discretion, that
          such PP [X] kW PEM Gen Set is commercially available and GE may elect
          during the sixty (60) day period following such notice to discontinue
          distribution of the Non-PP [X] kW PEM Gen Set and become the exclusive
          distributor of the PP [X] kW PEM Gen Set.

13. GENERAL PROVISIONS

     In the event of a conflict between the terms of this Amendment and any
     other ancillary documents related thereto, the terms of this Amendment
     shall apply.

     This Amendment may be executed in one or more counterparts, and by the
     different Parties hereto in separate counterparts, each of which when
     executed shall be deemed to be an original but all of which taken together
     shall constitute one and the same agreement.  Delivery of an executed
     counterpart of a signature page to this Amendment by telecopier shall be
     effective as delivery of a manually executed counterpart of this Amendment.

     This Amendment shall be construed without regard to any presumption or rule
     requiring construction or interpretation against the Party drafting or
     causing any instrument to be drafted.

     The headings contained in this Amendment are for convenience of reference
     only, do not constitute a party of this Amendment, and will not be used in
     interpreting this Amendment.

     Except as expressly set forth herein, this Amendment in no way alters or
     affects any other terms of the Agreement, which otherwise remains in full
     force and effect.

     IN WITNESS WHEREOF, the Parties have executed this Amendment as of the date
 first above written.



                                  PLUG POWER, INC.


                                  BY:  /S/ Gary Mittleman
                                     --------------------------
                                  NAME: GARY MITTLEMAN
                                  TITLE: PRESIDENT AND CEO



                                  GE FUEL CELL SYSTEMS, L.L.C.


                                  BY:  /S/ Barry Glickman
                                     --------------------------
                                  NAME: BARRY GLICKMAN
                                  TITLE: PRESIDENT

                                       10
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement


                                   SCHEDULE A


               RU1, RU2, RU3, AND RU4 PERFORMANCE SPECIFICATIONS

RU PRODUCT CONCEPT:

The RU product is a fuel cell-powered generating system for the home, designed
to provide the power needs of a "standard" household, defined as one using [X]
kWh per year. The RU system sits outside or inside the home and is connected
directly into the home's electrical system via the [X]. It may be run grid
independent, or grid-connected, depending on the end-user and local conditions.
The system runs on natural gas or LPG and is low cost, efficient, and
environmentally friendly.

The Product will be introduced over time as a series of three releases, preceded
by a Pre-Commercial Unit at the beginning of each release.  The Product releases
are called: RU1, RU2 and RU3 (to be released simultaneously), and RU4.  Each
subsequent release provides improved functionality, and cost savings to the
homeowner.  RU2 and RU3 are identical units except that RU2 is designed for
natural gas fuel and RU3 for LPG fuel.

PRE-COMMERCIAL UNITS:

The terminology Pre-Commercial (PCU) is identical to and interchangeable with
the Plug Power terminology [X] unit. The objective is for the PCUs to have
similar appearance, technology, functionality and performance to the Commercial
Unit (CU) RU product, including:

     1.  The PCU performance specifications are as indicated in the attached
         table (PCU RU Performance Specifications).

     2.  PCUs will be complete to the point where interfaces between major
         components (including, but not limited to, stack, reformer, inverter,
         etc.) will be the CU RU.

     3.  Weight, size, and physical appearance will be similar to the CU RU.

     4.  Operating methodology used to start, run and maintain the PCU will be
         the same as the CU RU.

RU1:

OVERVIEW: Grid connected, natural gas-fueled product providing complementary
power, capable of [X] purposes only.

MAIN FEATURES:

     . Grid connected unit with the ability to run [X] cumulative hours per
       year.
     . In [X] operation, system [X]supports the entire home.
     . RU1 recognizes [X] to the home for a period longer than [X].
     . RU1 recognizes the availability of grid power and resynchronizes without
       power loss to the home of more than [X].
     . In [X] mode the unit will regulate voltage and frequency while delivering
       power to the required specifications.
     . When operating in [X] the system will shut down.

                                       11
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

     .  The system will indicate mode change [X].
     .  The system is capable of [X] being present.
     .  The system has two available settings [X] kW power requirements.
     .  [X] operation is used when [X].  Operating strategy and implementation
        will be [X] as compared to [X].
     .  System efficiency will be evaluated based on the unit's ability to
        deliver kW to the house for each unit of natural gas fuel input to the
        system.  [X]
     .  The unit will have [X].
     .  The CU RU1 systems will meet the all of the performance specifications
        indicated for RU1 in the attached table ("CU RU Performance
        Specifications").

RU2:


OVERVIEW: Grid independent, natural gas-fueled product providing primary power
with grid providing back up service.

IMPROVEMENTS OVER RU1

     .  50Hz capability
     .  Improved efficiency
     .  Grid independent
     .  [X] load following capability (e.g., unit output response time to
        changes in customer load)

MAIN FEATURES:

     .  System has the ability to [X].
     .  System is designed to achieve total kW delivered to the homeowner with
        minimum natural gas usage.  [X]
     .  In the case of a [X].
     .  When [X], the system will shut down.
     .  The system packaging will provide [X].
     .  The system is capable of [X] being present.
     .  Transition of the house load between the system and the grid shall occur
        with a [X].  The system will indicate mode change [X].
     .  Plug Power will offer an [X].
     .  Plug Power will offer [X].
     .  The system will regulate voltage and frequency while delivering power to
        the required specifications.
     .  The unit will have a [X].
     .  The CU RU2 systems will meet the all of the performance specifications
        indicated for RU2 in the attached table ("CU RU Performance
        Specifications").

RU3:

OVERVIEW: Grid independent, LPG-fueled product providing primary, stand-alone
power.

IMPROVEMENTS OVER RU1

     .  LPG (HD5) fuel capability

                                       12
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

     .  50Hz capability
     .  Improved efficiency
     .  Grid independent
     .  [X] load following capability (e.g., unit output response time to
        changes in customer load)

MAIN FEATURES:

     .  The system is designed to run grid independent, without a grid back-up.
        However, the system has ability to [X].
     .  System is designed to achieve total kW delivered to the homeowner with
        minimum LPG usage [X].
     .  In the case of a [X].
     .  The system packaging will provide [X].
     .  The system is capable of starting without the grid being present.
     .  The system will regulate voltage and frequency while delivering power to
        the required specifications.
     .  When [X], the system will shut down.
     .  Transition of the house load between the system and the grid shall occur
        with [X].
     .  Plug Power will offer [X].
     .  The unit will have [X].
     .  The CU RU3 systems will meet the all of the performance specifications
        indicated for RU3 in the attached table ("CU RU Performance
        Specifications").

RU4:

OVERVIEW: Grid independent product targeted at grid displacement (i.e., cost
savings versus continuing to buy from grid is the primary customer CTQ)

IMPROVEMENTS OVER RU2/RU3
     .  [X] balanced
     .  Higher efficiency operation
     .  Higher reliability
     .  Lower operation and maintenance (O&M) costs

MAIN FEATURES:

     .  The system is designed to run grid independent, without a grid back-up.
        However, the system has ability to [X].
     .  System is designed to achieve total kW delivered to the homeowner with
        minimum fuel usage. [X].
     .  In the case of a [X], the system will [X].
     .  The system packaging will provide [X].
     .  The system will be [X] earlier RU versions is not needed.
     .  The system is designed for routine maintenance visits every [X] (as
        opposed to the [X] required for RU1, RU2 and RU3).
     .  The system will have options to utilize either natural gas or LPG.  The
        operating strategy will be the [X] for either fuel type, but the system
        efficiencies will [X] (as reflected in the "RU Performance
        Specifications" table).
     .  The system will [X].

                                       13
<PAGE>

                   Amendment to PP-GEFS Distributor Agreement

     .  The system is capable of starting without the grid being present.
     .  The system will regulate voltage and frequency while delivering power to
        the required specifications.
     .  When [X], the unit will provide [X]. If [X], the system will [X]. [X].
        If after the [X], the system will shut down.
     .  Transition of the house load between the system and the grid shall occur
        with a [X].  The system will indicate mode change via [X].
     .  Plug Power will offer an [X].  When grid connected the RU4 system will
        provide the [X].
     .  Plug Power will offer [X].
     .  The unit will have [X].
     .  The CU RU4 systems will meet the all of the performance specifications
        indicated for RU4 in the attached table ("CU RU Performance
        Specifications").

CERTIFICATIONS:

     .  CU versions of RU1, RU2, RU3, and RU4 (including the external packaging
        of all RU versions), will be compliant with all requisite standards
        (including, but not limited to, [X]).
     .  CU versions of RU1, RU2, RU3, and RU4 will have a [X] certification.
     .  PCU and CU versions of RU1, RU2, RU3, and RU4 must satisfy GE's
        environmental, health and safety (EH&S) review as a condition of
        acceptance.
     .  CU versions of RU1, RU2, RU3, and RU4 are intended to be capable of
        parallel operation with an electrical grid.  Hence, these products will
        be built with inverters that are [X].

DOCUMENTATION:

     .  PCU and CU versions of all RU products will be shipped with sufficient
        documentation (including, but not limited to, standard [X]) to allow for
        start-up and service by individuals with a skill level comparable to a
        typical [X], after such individual has completed [X] service training
        program.

SHIPPING:

     .  Plug Power will prepare all PCUs and CUs to allow for standard
        commercial shipment (e.g., truck, rail, cargo ship) to customer
        locations in the US and overseas.  Plug Power will be responsible for
        supplying all pertinent shipping paperwork including material safety
        data sheets  and hazardous material disclaimers (Reference GE
        requirements [X]).

MONITORING AND DIAGNOSTICS:

     .  PCU and CU versions of all RU products will be designed to accommodate
        [X]. At a minimum, the RU system [X] will allow the [X]. For grid
        parallel RU products, the [X] system will also allow for adjustment of
        the [X] on the unit.
     .  For PCU and CU versions of all RU products, maintenance providers must
        be able to [X].  [X].
     .  PCU and CU versions of all RU products will have the ability to [X].

INTERCONNECTION:

     .  PCU and CU versions of all RU products will be capable of
        interconnection to the electrical system of a typical single family
        residence. Each RU system will have a [X]. The [X] for RU1 will be
        defined by [X]. [X] for RU2, RU3 and RU4 will be defined no later than 2
        months prior to the respective PCU launch.

                                       14
<PAGE>

     .  PCU and CU versions of all RUs will be able to connect and operate to
        the utility grid without [X]; provided however, that the RU operate [X].
     .  Power transfer from the PCU and CU version of all RUs to the electric
        grid will take no longer than [X]. The power transfer will not [X].

Service Call Rate ("SCR"):

     [X]

PCU AND CU ACCEPTANCE CRITERIA:

  [X]

                                       15
<PAGE>

                       PCU RU PERFORMANCE SPECIFICATIONS

<TABLE>
<CAPTION>
                                      RU1           RU2           RU3          RU4            RU4
  ----------------------------------------------------------------------------------------------------
                                     GRID           GRID        Remote     Stand Alone    Stand Alone
                                  Parallel w/   Independent   Stand Alone     - Grid        - Grid
                                   emergency      w/ GRID                  Displacement  Displacement
                                  Stand Alone      backup
  ----------------------------------------------------------------------------------------------------
<S>                                 <C>             <C>         <C>          <C>            <C>
</TABLE>

                                       [X]

                        [Eight pages have been omitted]

                                       16
<PAGE>

                                   SCHEDULE B
                                   ----------

                  PP Direct Costs and Transfer Prices to GEFCS

<TABLE>
<CAPTION>
                              # OF UNITS    PP PROJECTED DIRECT COST*        GE PRICE
                    LOT #       IN LOT               ($/UNIT)            (TRANSFER PRICE)
                  -----------------------------------------------------------------------
<S>                 <C>     <C>             <C>                         <C>
RU1
RU2/3
RU4
2005 -
 </TABLE>

                                      [X]

                          [One page has been omitted]

                                       17