<PAGE>   1
                                                                    Exhibit 4.24


                            NATURAL RESOURCES CANADA

                    EFFICIENCY AND ALTERNATIVE ENERGY PROGRAM
               AMENDMENT NO. 1 TO THE CONTRIBUTION AGREEMENT BETWEEN
                       CANADA AND HYDROGENICS CORPORATION

                           THIS AMENDING AGREEMENT is made in duplicate

BETWEEN:

         HER MAJESTY THE QUEEN IN RIGHT OF CANADA ("CANADA"), represented by the
         Minister of Natural Resources Canada,
AND

         HYDROGENICS CORPORATION, incorporated under the laws in CANADA, (the
         "PROPONENT").


         WHEREAS Canada wishes to encourage the adoption of energy efficiency
and renewable energy technologies in all sectors of the Canadian economy and has
established the Efficiency and Alternative Energy Program for this purpose;

         WHEREAS Canada and the Proponent entered into an Agreement on January
10, 2001;

         AND WHEREAS Canada and the proponent wish to amend this Agreement;

         NOW, THEREFORE, Canada and the Proponent agree as follows:

1.  Under SECTION 1.1, "ELIGIBLE COSTS" March 31, 2002 to April 15, 2003;
    change Schedule B TO SCHEDULE B REVISED.

2.  Under "CONDUCT OF PROJECT", SECTION 3.2, change MARCH 31, 2002 TO
    March 31, 2003.

3.  Under "CONTRIBUTIONS", SECTION 4.4, change April 15, 2002 to APRIL 15,
    2003.

4.  Replace SCHEDULE A with SCHEDULE A REVISED (ATTACHED).

5.  Replace SCHEDULE B with SCHEDULE B REVISED (ATTACHED).

6.  Replace SCHEDULE C with SCHEDULE C REVISED (ATTACHED).

7.  ALL OTHER TERMS AND CONDITIONS OF THE AGREEMENT REMAIN IN FULL
    FORCE AND EFFECT.

IN WITNESS WHEREOF this Amending Agreement has been executed on behalf of HER
MAJESTY THE QUEEN IN RIGHT OF CANADA by an officer duly authorized by the
Minister of Natural Resources and by the PROPONENT, by an officer duly
authorized in that behalf.


                            HER MAJESTY THE QUEEN IN RIGHT OF CANADA


14 May 01                   /s/ N.R. Beck
-------------------         -----------------------------------------
Date                        N.R. Beck, Chief
                            Transportation Energy Technology
                            CETC/Energy Technology Branch

                            HYDROGENICS CORPORATION

                            /s/ Pierre Rivard
-------------------         -----------------------------------------
Date                        Pierre Rivard, President & CEO
<PAGE>   2


                               SCHEDULE A REVISED

                                STATEMENT OF WORK

BACKGROUND:

The Proponent has already developed a number of fuel cell electric generators.
Furthermore, the Proponent has been very successful in developing and marketing
a series of Automatic Fuel Cell Test Stations, which are considered by many the
best on the market today. As a rest, the Proponent has relevant expertise to
undertake the Project.

OBJECTIVE/PURPOSE:

Hydrogenics Corporation (the Company) intends to pursue commercial market
opportunities for fuel cell power generation and hydrogen production. It is
important that Canadian firms such as Hydrogenics respond authoritatively, to
capture an early position in this evanescent window of opportunity, possibly the
first mass market for fuel cells and for hydrogen energy.

DESCRIPTION/SCOPE:

The Proponent will engage in the development of an 50kW clean power electrical
generator employing Proton Exchange Membrane (PEM) fuel cell technology (the
Project). The following Tasks will be undertaken:

l.   Design and construct a 10kW Proton Exchange Membrane Fuel Cell (PEMFC)
     Auxiliary Power Unit (APU) in order to assess the technology on a more
     economical scale. The APU will contain the following major components:

     a)   a natural gas reformer fully integrated into the APU;

     b)   a PEMFC stack of 10kW;

     c)   a sub-scale form factor;

     d)   power conditioning unit (inverter)

2.   Design and construct a 50kW PEMFC Prototype Electric Generator capable of
     50kW of power @100VDC.

3.   Design, construct and test a natural gas reformer integrated into the 50kW
     prototype generator.

4.   Design, construct and test an embedded micro-computer supervisory data
     acquisition and control unit.

5.   Design, construct and test a power conditioning unit to home grid
     standards.

6.   Design, construct and test a heat recovery system connected to the hot
     water tank.

7.   Make necessary adjustments and redesigns on all components as dictated by
     the test results.

8.   Construct and test at least one Advanced Prototype Electric Generator
     capable of producing 50kW of power.

BENEFITS:

The proposed system will be adapted to existing fuel, targeting a cumulative
10-year GHG (Green House Gas) reduction potential of 3.3 MT (Megatonnes) of CO2
Equivalent in Canada. The potential for job and wealth creation in Canada is
also substantial. Research and Development jobs will be created immediately as a
result of this Project.
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                               SCHEDULE B REVISED

     ELIGIBLE COST

     Subject to the terms and conditions of this Agreement, the Proponent shall
     be reimbursed for Eligible Costs paid following successful completion of
     Project requirements. Canada shall pay an amount equal to the lesser of
     the dollar or percentage amount of the Eligible Costs of the Project as
     indicated below. Eligible Costs shall be approved in accordance with
     Treasury Board Guidelines associated with the execution of the various
     Tasks as described in Schedule A. The reimbursable Provincial Sales Tax and
     the Goods and Services Tax costs must be net of any tax rebate to which the
     Proponent is entitled.

<TABLE>
<CAPTION>

<S>                                                             <C>
    TOTAL ELIGIBLE COSTS                                        $6,000,000
</TABLE>

<TABLE>
<CAPTION>
    CONTRIBUTORS:                          $                             %

<S>                                    <C>                               <C>
CANADA*                                2,000,000                         33
PROPONENT                              4,000,000                         67
</TABLE>

* The Canada contribution will be allocated by fiscal year (FY) as follows:
          FY 2000/2001 = $500,000; FY 2001/2002 = $1,500,000.

ELIGIBLE COSTS:

1.   Labour at government approved rates.

2.   Materials and Supplies

3.   Charges for the use of special facilities

4.   Travel with prior approval from the Scientific Authority and under
     Treasury Board Guidelines

5.   Subcontracts

NON-ELIGIBLE COSTS:

1.   Property Taxes

2.   Purchase of Land
<PAGE>   4


                               SCHEDULE C REVISED

                                    REPORTS

1.1  TECHNICAL REPORTS

The Proponent shall submit quarterly Progress Reports within two weeks of the
ending of the quarter in question. The Proponent shall also submit a Draft
Final Report ON OR BEFORE MARCH 31, 2003. The Final Report shall contain any
revisions requested by the Minister. The Final Report shall be submitted ON OR
BEFORE MAY 31, 2003. These reports shall be to the satisfaction of the Minister
and shall describe in detail how Canada's contribution was utilized. The
Proponent shall deliver FIVE COPIES OF THE FINAL REPORT.

1.2  REVENUE REPORTS AND PAYMENTS

The Proponent shall provide to the Minister not later than 30 days after the end
of March and September in each calendar year, for the period of the payment
obligation described in ARTICLE 6.2 of this Agreement, a complete and accurate
report (including nil reports) of any Revenue received by the Proponent and
shall include any payments due to Canada. The reports shall:

          (a)  contain a statement of the Revenue received by the Proponent;

          (b)  include a computation of any share of the Revenue, if any, due
               and payable to Canada; and

          (c)  be certified as correct by the Treasurer or some other senior
               officer of the Proponent.

2. TECHNICAL REVIEW MEETINGS

   The Proponent shall organize and hold semiannual Progress Review Meetings on
   a date suitable to the Minister's representative and any key stakeholders.

3. MAJOR DELIVERABLES

   a) One 10kW Auxiliary Power Unit based on natural gas as the source of
      hydrogen.

   b) A Prototype 50kW Commercial Site Energy Unit, based on natural gas as the
      source of hydrogen.

   c) An Advanced Prototype 50kW Commercial Site Energy Unit, based on natural
      gas as the source of hydrogen.