<PAGE>

                                                                  EXECUTION COPY

                       VENTURES WEST 7 LIMITED PARTNERSHIP
                    VENTURES WEST 7 U.S. LIMITED PARTNERSHIP
                               HORTON TRADING LTD.
                                  ROGER HARPER
                                JACEK PIOTROWSKI
                                   GARRY SEDUN
                                  DAVID CHAPMAN
                                   JAMES DEAN
                               SEDUN FAMILY TRUST
                             PIOTROWSKI FAMILY TRUST

                                     - and -

                             HYDROGENICS CORPORATION

                                     - and -

                       GREENLIGHT POWER TECHNOLOGIES, INC.

--------------------------------------------------------------------------------

                               PURCHASE AGREEMENT

                               FOR MAJOR INVESTORS

                                 JANUARY 7, 2003

--------------------------------------------------------------------------------

                          Osler, Hoskin & Harcourt LLP

                                     - and -

                          Blake, Cassels & Graydon LLP

<PAGE>

                                TABLE OF CONTENTS

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ARTICLE 1 DEFINITIONS AND PRINCIPLES OF INTERPRETATION..................................................     2

         1.1      Definitions...........................................................................     2
         1.2      Certain Rules of Interpretation.......................................................    14
         1.3      Knowledge.............................................................................    16
         1.4      Entire Agreement......................................................................    16
         1.5      Schedules and Exhibits................................................................    16

ARTICLE 2 PURCHASE AND SALE.............................................................................    17

         2.1      Action by Vendors and Purchaser.......................................................    17
         2.2      Place of Closing......................................................................    19
         2.3      Tender................................................................................    19

ARTICLE 3 PURCHASE PRICE................................................................................    19

         3.1      Purchase Price........................................................................    19
         3.2      Satisfaction of Purchase Price........................................................    19
         3.3      Escrowed Shares.......................................................................    21
         3.4      Inventory Count.......................................................................    21
         3.5      Delivery of Closing Date Financial Statement..........................................    22
         3.6      Adjustments...........................................................................    22
         3.7      Objection to Closing Date Financial Statement.........................................    22
         3.8      Delivery of Cash Consideration........................................................    24
         3.9      Delivery of Equity Portion of Purchase Price..........................................    24
         3.10     Delivery of Escrowed Shares...........................................................    24

ARTICLE 4 REPRESENTATIONS AND WARRANTIES OF THE COMPANY.................................................    25

ARTICLE 5 REPRESENTATIONS AND WARRANTIES OF THE VENDORS.................................................    25

ARTICLE 6 REPRESENTATIONS AND WARRANTIES OF THE PURCHASER...............................................    25

ARTICLE 7 NON-WAIVER; SURVIVAL..........................................................................    25

         7.1      Non-Waiver............................................................................    25
         7.2      Nature and Survival...................................................................    26

ARTICLE 8 OTHER COVENANTS OF THE PARTIES................................................................    26

         8.1      Contractual Hold Periods..............................................................    26
         8.2      Closing Documentation.................................................................    31
         8.3      Confidentiality.......................................................................    31
         8.4      Preservation of Records...............................................................    33
         8.5      Stub Period Returns...................................................................    33
         8.6      Consent to Jurisdiction...............................................................    34
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                                TABLE OF CONTENTS
                                   (CONTINUED)

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         8.7      Securities Exemptions.................................................................    34
         8.8      Withholding Tax.......................................................................    35
         8.9      Continued Listing on TSX..............................................................    38
         8.10     Offer to Minor Vendors................................................................    38

ARTICLE 9 INDEMNIFICATION...............................................................................    38

         9.1      Indemnification by the Vendors........................................................    38
         9.2      Indemnification by the Purchaser......................................................    39
         9.3      Limitation Periods....................................................................    39
         9.4      Limitations on Indemnification Obligations............................................    40
         9.5      Indemnification Procedures for Third Party Claims.....................................    42
         9.6      Tax Status of Indemnification Payments................................................    43
         9.7      Escrowed Shares.......................................................................    44

ARTICLE 10 GENERAL......................................................................................    44

         10.1     Public Notices........................................................................    44
         10.2     Expenses..............................................................................    44
         10.3     Notices...............................................................................    44
         10.4     Interest Act Disclosure...............................................................    46
         10.5     Assignment............................................................................    46
         10.6     Enurement.............................................................................    46
         10.7     Amendment.............................................................................    46
         10.8     Further Assurances....................................................................    47
         10.9     Independent Legal Advice..............................................................    47
         10.10    Attornment............................................................................    47
         10.11    Execution and Counterparts............................................................    47

LIST OF SCHEDULES

SCHEDULE A LIST OF MAJOR VENDORS AND SECURITIES HELD

SCHEDULE A1 SECURITIES PURCHASED FOR CASH

SCHEDULE A2 SECURITIES PURCHASED FOR SHARES AND ESCROW

SCHEDULE 1.1 PERMITTED ENCUMBRANCES

SCHEDULE 3.2 FORM OF WARRANT

SCHEDULE 3.9 DIRECTION RE EQUITY PORTION OF THE PURCHASE PRICE

SCHEDULE 3.10 DIRECTION RE ESCROWED SHARES

SCHEDULE 4 REPRESENTATIONS AND WARRANTIES OF THE COMPANY
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                                TABLE OF CONTENTS
                                   (CONTINUED)

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EXHIBIT A DISCLOSURE SCHEDULE

EXHIBIT B DISCLOSURE DOCUMENTS

SCHEDULE 5 REPRESENTATIONS AND WARRANTIES OF THE VENDORS

SCHEDULE 6 REPRESENTATIONS AND WARRANTIES OF THE PURCHASER

SCHEDULE 8.1 FORM OF DECLARATION FOR REMOVAL OF U.S. LEGEND

SCHEDULE 10.3 NOTICES
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                                     -iii-

<PAGE>

         THIS PURCHASE AGREEMENT is made as of January 7, 2003

BETWEEN:

                  HYDROGENICS CORPORATION, a corporation governed by the laws of
                  Canada,

                  (the "Purchaser")

                                     - and -

                  GREENLIGHT POWER TECHNOLOGIES, INC., a corporation governed by
                  the laws of Canada

                  (the "Company")

                                     - and -

                  THE SHAREHOLDERS OF THE COMPANY, listed on Schedule A

                  (collectively the "Vendors").

RECITALS:

A.       Each of the Vendors beneficially owns and controls such number of
         securities of the Company as is set out opposite its name in Schedule
         A.

B.       Each of the Vendors has agreed to sell to the Purchaser and the
         Purchaser has agreed to purchase from such Vendor all of the issued and
         outstanding securities of the Company, owned by such Vendor, on the
         terms and conditions of this Agreement.

THEREFORE, the parties agree as follows:

<PAGE>

                                      - 2 -

                                   ARTICLE 1
                  DEFINITIONS AND PRINCIPLES OF INTERPRETATION

1.1      DEFINITIONS

         (a)      Whenever used in this Agreement, the following words and terms
                  have the meanings set out below:

         "ACCOUNTS RECEIVABLE" means accounts receivable, bills receivable,
         trade accounts, unbilled contracts, book debts and insurance claims
         recorded as receivable in the Books and Records and any other amount
         due to the Company including any refunds and rebates, and the benefit
         of all security (including cash deposits), guarantees and other
         collateral held by the Company as determined and calculated in
         accordance with GAAP;

         "ACCRUED LIABILITIES" means accrued liabilities of the Company
         including accruals for vacation pay, customer rebates and allowances
         for product returns as determined and calculated in accordance with
         GAAP;

         "AFFILIATE" of any Person means, at the time such determination is
         being made, any other Person controlling, controlled by or under common
         control with such first Person, in each case, whether directly or
         indirectly, and "CONTROL" and any derivation thereof means the
         possession, directly or indirectly, of the power to direct or
         significantly influence the management and policies, business or
         affairs of a Person whether through the ownership of voting securities
         or otherwise;

         "AGREEMENT" means this Purchase Agreement, including all schedules, and
         all amendments or restatements, as permitted, and references to
         "ARTICLE" or "SECTION" mean the specified Article or Section of this
         Agreement;

         "ARM'S LENGTH" has the meaning that it has for purposes of the Income
         Tax Act (Canada);

         "AUDITOR" means PricewaterhouseCoopers LLP, Chartered Accountants;

         "BALANCE SHEET" means the unaudited balance sheet of the Company as at
         September 30, 2002, forming part of the Financial Statements;

<PAGE>

                                      - 3 -

         "BENEFIT PLANS" means plans, arrangements, agreements, programs,
         policies, practices or undertakings, whether oral or written, formal or
         informal, funded or unfunded, registered or unregistered to which the
         Company is a party or by which the Company is bound or under which the
         Company has, or will have, any liability or contingent liability,
         relating to:

         (a)      Pension Plans;

         (b)      plans in the nature of insurance plans, providing for
                  employment benefits relating to disability or wage or benefits
                  continuation during periods of absence from work (including,
                  short term disability, long term disability, workers
                  compensation and maternity and parental leave), and any and
                  all employment benefits relating to hospitalization,
                  healthcare, medical or dental treatments or expenses, life
                  insurance, accidental death and dismemberment insurance, death
                  or survivor's benefits and supplementary employment insurance,
                  in each case regardless of whether or not such benefits are
                  insured or self-insured; or

         (c)      plans in the nature of compensation plans, which means all
                  employment benefits relating to bonuses, incentive pay or
                  compensation, performance compensation, deferred compensation,
                  profit sharing or deferred profit sharing, share purchase,
                  share option, stock appreciation, phantom stock, vacation or
                  vacation pay, sick pay, severance or termination pay, employee
                  loans or separation from service benefits, or any other type
                  of arrangement providing for compensation or benefits
                  additional to base pay or salary;

         with respect to any of its Employees or former employees (or any
         spouses, dependants, survivors or beneficiaries of any such Employees
         or former employees), directors or officers, individuals working on
         contract with the Company or other individuals providing services to
         any of them of a kind normally provided by employees or eligible
         dependants of such Person excluding Statutory Plans;

         "BOOKS AND RECORDS" means books and records of the Company (whether
         held by the Company or the Vendors), including financial, corporate,
         operations and sales books,

<PAGE>

                                      - 4 -

         books of account, sales and purchase records, lists of suppliers and
         customers, formulae, business reports, plans and projections and all
         other documents, surveys, plans, files, records, assessments,
         correspondence, and other data and information, financial or otherwise,
         including all data and information stored on computer-related or other
         electronic media;

         "BUSINESS DAY" means any day, other than a Saturday or Sunday, on which
         the Royal Bank of Canada in Toronto, Ontario is open for commercial
         banking business during normal banking hours;

         "CHAPMAN OPTION" means the Option Agreement dated April 4, 2001 between
         David Chapman and Horton Trading Ltd.;

         "CHAPMAN OPTION ASSIGNMENT AGREEMENT" means the Amendment and
         Assignment of Option Agreement dated as of the date hereof in the form
         attached as Schedule 2.1;

         "CLAIMS" includes claims, demands, complaints, actions, suits, causes
         of action, assessments or reassessments, charges, judgments, debts,
         liabilities, expenses, costs, damages or losses, contingent or
         otherwise, including loss of value, professional fees, including fees
         of legal counsel on a solicitor and his or her own client basis, and
         all costs incurred in investigating or pursuing any of the foregoing or
         any proceeding relating to any of the foregoing;

         "CLOSING" means the completion of the sale to and purchase by the
         Purchaser of the Purchased Securities under this Agreement;

         "CLOSING DATE" means the date this Agreement is entered into;

         "CLOSING DATE FINANCIAL STATEMENT" means the balance sheet of the
         Company as at December 31, 2002 and the accompanying statements of
         operations, retained earnings (deficit) and cash flows for the year
         then ended, prepared using the Purchaser's Completed Contract Method of
         Revenue Recognition, and showing all of the assets and liabilities of
         the Company, and shall also include a statement of the Closing Net
         Assets, together with an unqualified opinion of the Auditor to the
         effect that the Closing Date Financial Statement has been prepared in
         accordance with a disclosed basis of accounting

<PAGE>

                                      - 5 -

         (substantially in accordance with GAAP except for the change in revenue
         recognition policy from percentage of completion to Purchaser's
         Completed Contract Method of Revenue Recognition) and presents fairly
         in all material respects the assets and liabilities of the Company;

         "CLOSING NET ASSETS" means an amount equal to the total assets less
         total liabilities derived from the balance sheet prepared as part of
         the Closing Date Financial Statement (provided that such calculation
         shall exclude the Company's Transaction Expenses);

         "CLOSING REVENUE" means the total revenue amount reflected on the
         statements of operations prepared as part of the Closing Date Financial
         Statement;

         "CLOSING TIME" means 11:59 p.m. (Vancouver time), on the Closing Date
         or such other time on such date as the Parties may agree in writing as
         the time at which the Closing shall take place;

         "COLLECTIVE AGREEMENTS" means collective agreements and related
         documents including benefit agreements, letters of understanding,
         letters of intent and other written communications with bargaining
         agents or unions by which the Company is bound or which impose any
         obligations upon the Company or set out the understanding of the
         parties with respect to the meaning of any provisions of such
         collective agreements;

         "COMPANY'S TRANSACTION EXPENSES" means all of the Company's legal,
         accounting and investment banking expenses incurred in connection with
         the transactions contemplated by this Agreement and the Company's
         current proposed financing;

         "CONFIDENTIALITY AGREEMENT" has the meaning given in Section 8.3;

         "CONTRACTS" means contracts, licences, leases, agreements, commitments,
         entitlements or engagements to which the Company is a party or by which
         it is bound or under which the Company has, or will have, any liability
         or contingent liability, and includes any quotation, order or tender
         for any contract which remains open for acceptance and any warranty,
         guarantee or commitment (express or implied);

         "DEAN OPTION" means the Option Agreement dated April 4, 2001 between
         James Dean and Horton Trading Ltd.;

<PAGE>

                                      - 6 -

         "DEAN OPTION ASSIGNMENT AGREEMENT" means the Amendment and Assignment
         of Option Agreement dated as of the date hereof in the form attached as
         Schedule 2.1;

         "DISCLOSURE DOCUMENTS" means the documents provided by the Company to
         the Purchaser which are listed in Exhibit B to Schedule 4;

         "DISCLOSURE SCHEDULE" means Exhibit A to Schedule 4;

         "EFFECTIVE DATE" means January 7, 2003 or such other date as the
         parties may agree in writing;

         "EFFECTIVE TIME" means 11:59 p.m. (Vancouver Time) on the Effective
         Date;

         "EMPLOYEES" means those individuals employed or retained by the Company
         on a full-time, part-time or temporary basis, including those employees
         on disability leave, parental leave or other absence;

         "EMPLOYMENT CONTRACTS" means Contracts, whether oral or written,
         relating to an Employee, including any communication or practice
         relating to an Employee which imposes any obligation on the Company;

         "ENCUMBRANCES" means pledges, liens, charges, security interests,
         leases, title retention agreements, mortgages, restrictions,
         developments or similar agreements, easements, rights-of-way, title
         defects, options or adverse claims or encumbrances of any kind or
         character whatsoever;

         "ENVIRONMENT" means the environment or natural environment as defined
         in any Environmental Laws and includes air, surface water, ground
         water, land surface, soil, subsurface strata, any sewer system and the
         environment in the workplace;

         "ENVIRONMENTAL APPROVALS" means approvals, permits, certificates,
         licences, authorizations, consents, agreements, instructions,
         directions, registrations or approvals issued, granted, conferred or
         required by a Governmental Authority pursuant to an Environmental Law
         with respect to the operations, business or assets of the Company and
         includes any sewer surcharge agreements;

<PAGE>

                                      - 7 -

         "ENVIRONMENTAL LAWS" means those Laws relating to the Environment,
         product liability, or employee or public health or safety, and includes
         any Laws relating to the storage, generation, use, handling,
         manufacture, processing, labelling, advertising, sale, display,
         transportation, treatment, reuse, recycling, Release and disposal of
         Hazardous Substances;

         "EQUIPMENT CONTRACTS" means motor vehicle leases, equipment leases,
         leases of computer hardware and computer systems, conditional sales
         contracts, title retention agreements and other similar agreements
         relating to equipment used by the Company;

         "ESCROW AGREEMENT" means the escrow agreement, dated as of the date
         hereof, between the Vendors, the Purchaser and the Escrow Agent;

         "ESCROW AGENT" has the meaning ascribed thereto in the Escrow
         Agreement;

         "ESCROWED SHARES" means the 970,061 Hydrogenics Shares to be deposited
         with the Escrow Agent pursuant to Section 3.2;

         "FINANCIAL STATEMENTS" means the audited balance sheet of the Company
         as at August 31, 2001 and the related audited financial statements of
         operations and retained earnings (deficit) and cash flow for the year
         then ended and the audited balance sheet as at December 31, 2001 and
         the related audited financial statements of operations and retained
         earnings (deficit) and cash flow for the four months then ended and all
         notes thereto as reported upon by KPMG LLP; and an unaudited balance
         sheet of the Company as at September 30, 2002 and the related unaudited
         statements of operations and retained earnings (deficit) and cash flow
         for the nine months then ended;

         "FIXED ASSETS" means fixed assets, machinery, equipment including
         computer hardware and telecommunications equipment, fixtures,
         furniture, furnishings, vehicles, material handling equipment,
         implements, parts, tools, jigs, dies, molds, patterns and tooling, or
         spare parts owned or used or held (including assets under capital
         leases) by the Company, including any which are in storage or in
         transit, and other tangible property and facilities used by the Company
         whether located in or on the premises of the Company or elsewhere,
         including the assets listed and described in the Disclosure Documents;

<PAGE>

                                      - 8 -

         "GAAP" means generally accepted accounting principles as defined by the
         Accounting Standards Board of the Canadian Institute of Chartered
         Accountants in the Handbook of the Canadian Institute of Chartered
         Accountants as they exist on the date of this Agreement;

         "GOVERNMENTAL AUTHORITY" means any (i) multinational, federal,
         provincial, state, municipal, local or other government, governmental
         or public department, central bank, court, tribunal, dispute
         settlement panel or body or other law, rule or regulation-making
         entity, commission, board, bureau, Crown corporation, agency or
         instrumentality, domestic or foreign, (ii) any subdivision or authority
         of any of the foregoing, or (iii) any quasi-governmental or private
         body exercising any regulatory, expropriation or taxing authority under
         or for the account of any of the above;

         "GOVERNMENTAL AUTHORIZATIONS" means authorizations, approvals,
         including Environmental Approvals, orders, certificates, consents,
         directives, notices, licences, permits, variances, registrations or
         similar rights issued to or required by the Company by or from any
         Governmental Authority;

         "HAZARDOUS SUBSTANCES" means any pollutants, contaminants, wastes of
         any nature, hazardous substances, hazardous materials, toxic
         substances, prohibited substances, dangerous substances or dangerous
         goods as defined, judicially interpreted or identified in any
         Environmental Laws including any asbestos, asbestos-containing
         materials, mould, microbial organisms or substances related thereto;

         "HYDROGENICS SHARES" means common shares in the capital of the
         Purchaser;

         "INDEPENDENT AUDITOR" means Ernst & Young LLP or such other independent
         auditing firm as the Parties may otherwise agree;

         "INFORMATION TECHNOLOGY" means all computer hardware, software in
         source code and object code form (including documentation, interfaces
         and development tools), websites for the Company, databases,
         telecommunications equipment and facilities and other information
         technology systems owned, used or held by the Company;

<PAGE>

                                      - 9 -

         "INTELLECTUAL PROPERTY" means intellectual property rights, whether
         registered or not, owned, used or held by the Company, including:

         (a)      inventions, pending patent applications (including
                  divisionals, reissues, renewals, re-examinations,
                  continuations, continuations-in-part and extensions) and
                  issued patents, including those inventions, pending patent
                  applications and issued patents listed and described in the
                  Disclosure Documents;

         (b)      trade-marks, trade-names, brands, trade dress, business names
                  and other indicia of origin, including those listed and
                  described in the Disclosure Documents;

         (c)      copyrights, including those copyright registrations and
                  applications listed and described in the Disclosure Documents;

         (d)      industrial designs and similar rights, including those
                  registrations and applications listed and described in the
                  Disclosure Documents; and

         (e)      integrated circuit topographies and similar rights, including
                  those registrations and applications listed and described in
                  the Disclosure Documents;

         "INVENTORIES" means inventories of every kind and nature and
         wheresoever situate of the Company including inventories of raw
         materials, work-in-progress, finished goods and by-products, spare
         parts, operating supplies and packaging materials and net of reasonable
         provisions, provided that raw materials and supplies are valued at the
         lower of cost, determined on a first-in first-out basis, or market,
         market is defined as replacement cost and finished goods and
         work-in-progress are recorded at the lower of cost and net realizable
         value;

         "KEY EXECUTIVES" means Roger Harper, Jacek Piotrowski (together with
         the Piotrowski Family Trust), Garry Sedun (together with the Sedun
         Family Trust), David Chapman and James Dean;

         "LAWS" means applicable laws (including common law), statutes, by-laws,
         rules, regulations, orders, ordinances, protocols, codes, guidelines,
         treaties, policies, notices,

<PAGE>

                                     - 10 -

         directions, decrees, judgments, awards or requirements, in each case of
         any Governmental Authority;

         "LEASED REAL PROPERTY" means premises which are used by the Company
         which are leased, subleased, licensed or otherwise occupied by the
         Company and the interest of the Company in all plants, buildings,
         structures, fixtures, erections, improvements, easements,
         rights-of-way, spur tracks and other appurtenances situate on or
         forming part of such premises;

         "MATERIAL ADVERSE EFFECT" in respect of the Purchaser shall mean any
         material adverse effect on the condition (financial or otherwise),
         earnings, business, prospects or properties of the Purchaser whether or
         not arising from transactions in the ordinary course of business;

         "MATERIAL CONTRACT" means any Contract (i) involving aggregate payments
         to or by the Company in excess of $25,000, (ii) involving rights or
         obligations of the Company that may reasonably extend beyond one year,
         (iii) which is outside the ordinary course of business, (iv) which does
         not or cannot be terminated without penalty on less than three months'
         notice, (v) which restricts in any way the business or activities of
         the Company, or (vi) which, if terminated without the consent of the
         Company, would have a significant adverse effect on the Company;

         "NOTICE" has the meaning given in Section 10.3;

         "OCCUPATIONAL HEALTH AND SAFETY LAWS" means all Laws relating in full
         or in part to the protection of employee or worker health and safety;

         "OWNED REAL PROPERTY" means real property, owned or purported to be
         owned in fee simple, by the Company or real property, other than Leased
         Real Property, in which the Company has an interest, including all
         plants, buildings, structures, fixtures, erections, improvements,
         easements, rights-of-way, spur tracks and other appurtenances situate
         on or forming part of such real property;

         "PARTIES" means the Vendors and the Purchaser collectively, and "PARTY"
         means any one of them;

<PAGE>

                                     - 11 -

         "PENSION PLANS" means all benefits relating to retirement or retirement
         savings including pension plans, pensions or supplemental pensions,
         "registered retirement savings plans" (as defined in the Income Tax Act
         (Canada)), "registered pension plans" (as defined in the Income Tax Act
         (Canada)) and "retirement compensation arrangements" (as defined in the
         Income Tax Act (Canada));

         "PERMITTED ENCUMBRANCES" means the Encumbrances listed in Schedule 1.1;

         "PERSON" means any individual, sole proprietorship, partnership, firm,
         entity, unincorporated association, unincorporated syndicate,
         unincorporated organization, trust, body corporate, Governmental
         Authority, and where the context requires any of the foregoing when
         they are acting as trustee, executor, administrator or other legal
         representative;

         "PERSONAL INFORMATION" means any information in the possession of the
         Company about an identifiable individual other than the name, title or
         business address or telephone number of an Employee;

         "PROPORTIONATE SHARE" means in respect of each of the Vendors the
         percentage set out opposite the name of such Vendor in Schedule A;

         "PURCHASE PRICE" has the meaning given in Section 3.1;

         "PURCHASED SECURITIES" means all of the shares, warrants and options in
         the capital of the Company owned by the Vendors and which are as listed
         in Schedule A and the Chapman Option and the Dean Option;

         "PURCHASER'S FINANCIAL STATEMENTS" means the audited balance sheet of
         the Purchaser for the fiscal year ending December 31, 2001 and the
         accompanying statements of income, retained earnings and changes in
         financial position for the year then ended and all notes thereto as
         reported upon by PricewaterhouseCoopers LLP; and the unaudited interim
         financial statements of the Company for the nine month period ending
         September 30, 2002;

         "PURCHASER'S COMPLETED CONTRACT METHOD OF REVENUE RECOGNITION" means
         the recognition of revenue related to the sale of fuel cell test
         stations and other related

<PAGE>

                                     - 12 -

         systems employed by the Purchaser whereby revenue is recognized when
         goods are delivered, title passes to the customer and collection is
         reasonably assured provided that in situations where customer
         acceptance is considered to be substantive to the transaction, revenue
         is recognized only after such acceptance has been received from the
         customer;

         "REAL PROPERTY" means the Owned Real Property and the Leased Real
         Property;

         "REAL PROPERTY LEASES" means those agreements to lease, leases,
         subleases or licences or other agreements or rights pursuant to which
         the Company uses or occupies the Leased Real Property;

         "RELEASE" has the meaning prescribed in any Environmental Laws and
         includes any sudden, intermittent or gradual release, spill, leak,
         pumping, addition, pouring, emission, emptying, discharge, injection,
         escape, leaching, disposal, dumping, deposit, spraying, burial,
         abandonment, incineration, seepage, placement or introduction, whether
         accidental or intentional;

         "REMEDIAL ORDER" means any administrative complaint, direction, order
         or sanction issued, filed, imposed or threatened by any Governmental
         Authority pursuant to any Environmental Laws and includes any order
         requiring investigation, assessment or remediation of any site or
         Hazardous Substance, or requiring that any Release or any other
         activity be reduced, modified or eliminated or requiring any form of
         payment or co-operation be provided to any Governmental Authority;

         "SEC" means the United States Securities and Exchange Commission;

         "SECURITIES HOLDERS" means the holders of any of the outstanding
         securities of the Company;

         "SHAREHOLDERS AGREEMENT" means the Company's shareholders agreement
         dated April 4, 2001;

         "STATUTORY PLANS" means statutory Benefit Plans which the Company is
         required to comply with, including the Canada Pension Plan and plans
         administered pursuant to applicable health tax, workers' compensation
         and unemployment insurance legislation;

<PAGE>

                                     - 13 -

         "SUBSIDIARIES" means corporations in which the Company has a
         controlling interest as defined in the Canada Business Corporations
         Act;

         "TAX RETURNS" includes all returns, reports, declarations, elections,
         notices, filings, forms, statements and other documents (whether in
         tangible, electronic or other form) and including any amendments,
         schedules, attachments, supplements, appendices and exhibits thereto,
         made, prepared, filed or required to be made, prepared or filed by Law
         in respect of Taxes;

         "TAXES" includes any taxes, duties, fees, premiums, assessments,
         imposts, levies and other charges of any kind whatsoever imposed by any
         Governmental Authority, including all interest, penalties, fines,
         additions to tax or other additional amounts imposed by any
         Governmental Authority in respect thereof, and including those levied
         on, or measured by, or referred to as, income, gross receipts, profits,
         capital, transfer, land transfer, sales, goods and services, harmonized
         sales, use, value-added, excise, stamp, withholding, business,
         franchising, property, development, occupancy, employer health,
         payroll, employment, health, social services, education and social
         security taxes, all surtaxes, all customs duties and import and export
         taxes, countervail and anti-dumping, all licence, franchise and
         registration fees and all employment insurance, health insurance and
         Canada, Quebec and other government pension plan premiums or
         contributions;

         "TECHNICAL INFORMATION" means all know-how and related technical
         knowledge owned, used or held by the Company including:

         (a)      trade secrets, confidential information and other proprietary
                  know-how;

         (b)      public information and non-proprietary know-how;

         (c)      information of a scientific, technical, financial or business
                  nature regardless of its form;

         (d)      uniform resource locators, domain names, telephone, telecopy
                  and email addresses, and UPC consumer packaging codes; and

<PAGE>

                                     - 14 -

         (e)      documented research, forecasts, studies, marketing plans,
                  budgets, market data, developmental, demonstration or
                  engineering work, information that can be used to define a
                  design or process or procure, produce, support or operate
                  material and equipment, methods of production and procedures,
                  all formulas and designs and drawings, blueprints, patterns,
                  plans, flow charts, parts lists, manuals and records,
                  specifications, and test data;

         "TECHNOLOGY" means all Intellectual Property, Technical Information and
         Information Technology;

         "TRANSFER AGENT" means CIBC Mellon Trust Company in its capacity as
         Canadian registrar and transfer agent of the Purchaser;

         "UNION PLANS" means Benefit Plans which are or are required to be
         established and maintained pursuant to a Collective Agreement and which
         are not maintained or administered by the Company;

         "U.S. SECURITIES ACT" means the United States Securities Act of 1933,
         as amended;

         "VENTURES WEST" means collectively Ventures West 7 Limited Partnership
         and VW7US;

         "VW7US" means Ventures West 7 U.S. Limited Partnership; and

         "WARRANT(S)" means the warrant to acquire Hydrogenics Shares for
         nominal consideration on or before January 10, 2003 in the form
         attached as Schedule 3.2.

1.2      CERTAIN RULES OF INTERPRETATION

In this Agreement:

         (a)      CONSENT - Whenever a provision of this Agreement requires an
                  approval or consent to be given by a Party and such approval
                  or consent is not delivered within the applicable time limit,
                  then, unless otherwise specified, the Party whose consent or
                  approval is required shall be conclusively deemed to have
                  withheld its approval or consent.

<PAGE>

                                     - 15 -

         (b)      CURRENCY - Unless otherwise specified, all references to money
                  amounts are to lawful currency of Canada.

         (c)      GOVERNING LAW - This Agreement is a contract made under and
                  shall be governed by and construed in accordance with the laws
                  of the Province of Ontario and the federal laws of Canada
                  applicable in the Province of Ontario.

         (d)      HEADINGS - Headings of Articles and Sections are inserted for
                  convenience of reference only and shall not affect the
                  construction or interpretation of this Agreement.

         (e)      INCLUDING - Where the word "including" or "includes" is used
                  in this Agreement, it means "including (or includes) without
                  limitation".

         (f)      NO STRICT CONSTRUCTION - The language used in this Agreement
                  is the language chosen by the Parties to express their mutual
                  intent, and no rule of strict construction shall be applied
                  against any Party.

         (g)      NUMBER AND GENDER - Unless the context otherwise requires,
                  words importing the singular include the plural and vice versa
                  and words importing gender include all genders.

         (h)      SEVERABILITY - If, in any jurisdiction, any provision of this
                  Agreement or its application to any Party or circumstance is
                  restricted, prohibited or unenforceable, such provision shall,
                  as to such jurisdiction, be ineffective only to the extent of
                  such restriction, prohibition or unenforceability without
                  invalidating the remaining provisions of this Agreement and
                  without affecting the validity or enforceability of such
                  provision in any other jurisdiction or without affecting its
                  application to other Parties or circumstances.

         (i)      STATUTORY REFERENCES - A reference to a statute includes all
                  regulations made pursuant to such statute and, unless
                  otherwise specified, the provisions of any

<PAGE>

                                     - 16 -

                  statute or regulation which amends, supplements or supersedes
                  any such statute or any such regulation.

         (j)      TIME - Time is of the essence in the performance of the
                  Parties' respective obligations.

         (k)      TIME PERIODS - Unless otherwise specified, time periods within
                  or following which any payment is to be made or act is to be
                  done shall be calculated by excluding the day on which the
                  period commences and including the day on which the period
                  ends and by extending the period to the next Business Day
                  following if the last day of the period is not a Business Day.

1.3      KNOWLEDGE

Any reference to the knowledge of any Party means to the knowledge, information
and belief of such Party after reviewing all relevant records of the Party and
making due inquiries regarding the relevant matter of all relevant directors,
officers and employees of the Party.

1.4      ENTIRE AGREEMENT

This Agreement and the agreements and other documents required to be delivered
pursuant to this Agreement, constitute the entire agreement between the Parties
and set out all the covenants, promises, warranties, representations,
conditions, understandings and agreements between the Parties pertaining to the
subject matter of this Agreement and supersede all prior agreements,
understandings, negotiations and discussions, whether oral or written. There are
no covenants, promises, warranties, representations, conditions, understandings
or other agreements, oral or written, express, implied or collateral between the
Parties in connection with the subject matter of this Agreement except as
specifically set forth in this Agreement and any document required to be
delivered pursuant to this Agreement.

1.5      SCHEDULES AND EXHIBITS

The schedules and exhibits to this Agreement, as listed below, are an integral
part of this Agreement:

<PAGE>

                                     - 17 -

SCHEDULE                   DESCRIPTION

Schedule A                 List of Major Investors and Securities Held

Schedule A1                Securities Purchased for Cash

Schedule A2                Securities Purchased for Shares and Escrow

Schedule 1.1               Permitted Encumbrances

Schedule 2.1               Form of Option Amendment and Assignment Agreement

Schedule 3.2               Form of Warrant

Schedule 3.9               Direction Re: Equity Portion of the Purchase Price

Schedule 3.10              Direction Re: Escrowed Shares

Schedule 4                 Representations and Warranties of the Company

Exhibit A                  Disclosure Schedule

Exhibit B                  Disclosure Documents

Schedule 5                 Representations and Warranties of the Vendors

Schedule 6                 Representations and Warranties of the Purchaser

Schedule 8.1               Form of Declaration For Removal of U.S. Legend

Schedule 10.3              Notices

                                   ARTICLE 2
                                PURCHASE AND SALE

2.1      ACTION BY VENDORS AND PURCHASER

Subject to the provisions of this Agreement, with effect as of and from the date
hereof:

         (a)      Purchase and Sale of Purchased Securities - each of the
                  Vendors hereby sells and the Purchaser hereby purchases:

                  (i)      the Purchased Securities set out on Schedule A1 for
                           the consideration provided for in Section 3.2(a);

<PAGE>

                                     - 18 -

                  (ii)     the Purchased Securities set out on Schedule A2 for
                           the consideration provided for in Section 3.2(b);

                  (iii)    in the case of David Chapman and James Dean, the
                           Chapman Option and Dean Option, respectively, for the
                           consideration provided in Section 3.2(c); and

                  (iv)     in the case of Horton Trading Ltd., the Purchased
                           Securities set out in Schedule A4 for the
                           consideration provided in Section 3.2(d) pursuant to
                           the exercise by the Purchaser of the Chapman Option
                           and Dean Option.

         (b)      PAYMENT OF PURCHASE PRICE - the Purchaser shall pay the
                  Purchase Price to the Vendors as provided in Sections 3.2,
                  3.3, 3.6 and 3.7.

         (c)      TRANSFER AND DELIVERY OF THE PURCHASED SECURITIES - each of
                  the Vendors shall transfer and deliver to the Purchaser
                  certificates representing the Purchased Securities held by
                  such Vendor duly endorsed in blank for transfer, or
                  accompanied by irrevocable security transfer powers of
                  attorney duly executed in blank or such other instrument of
                  transfer as may be required by the Purchaser, in each case by
                  the holder of record, and the Company shall take such steps as
                  shall be necessary to enter the Purchaser or its nominee(s)
                  upon the books of the Company as the holder of the Purchased
                  Securities held by such Vendor and to issue one or more
                  certificates to the Purchaser or its nominee(s) representing
                  the Purchased Securities held by each Vendor as appropriate;
                  and

         (d)      OTHER DOCUMENTS - each of the Vendors, the Company and the
                  Purchaser shall deliver such other documents as may be
                  reasonably necessary to complete the transactions provided for
                  in this Agreement.


<PAGE>

                                     - 19 -

2.2      PLACE OF CLOSING

The Closing shall take place at the Closing Time at the offices of Blake,
Cassels & Graydon LLP located at 2600, Three Bentall Centre, 595 Burrard Street,
Vancouver, British Columbia, V6X 1L3, or at such other place as may be agreed
upon by the Vendors and the Purchaser.

2.3      TENDER

Any tender of documents or money under this Agreement may be made upon the
Parties or their respective counsel and money may be tendered by official bank
draft drawn upon a Canadian chartered bank or by negotiable cheque payable in
Canadian funds and certified by a Canadian chartered bank or trust company or,
with the consent of the Party entitled to payment, by wire transfer of
immediately available funds to the account specified by that Party.

                                   ARTICLE 3

                                 PURCHASE PRICE

3.1      PURCHASE PRICE

The aggregate amount payable by the Purchaser for the Purchased Securities (the
"Purchase Price") shall be the amount of $30,716,301.59, subject to adjustment
as provided for in Section 3.6 and Section 9.6.

3.2      SATISFACTION OF PURCHASE PRICE

The Purchaser shall satisfy the Purchase Price as follows:

         (a)      in order to purchase the securities listed on Schedule A1, by
                  delivery of the following:

                  (i)      the cash consideration set out opposite the name of
                           each Vendor in Schedule A1;

<PAGE>

                                     - 20 -

                  (ii)     the delivery to the Escrow Agent of the Escrowed
                           Shares in respect of each Vendor being the number of
                           Escrowed Shares set out opposite the name of each
                           Vendor in Schedule A1; and

                  (iii)    the delivery to each of the Vendors of the equity
                           portion of the Purchase Price for the securities
                           listed on Schedule A1 (less the Escrowed Shares
                           delivered to the Escrow Agent pursuant to Section
                           3.2(a)(ii) above) being that number of Hydrogenics
                           Shares set out opposite the name of such Vendor on
                           Schedule A1;

         (b)      in order to purchase the securities listed on Schedule A2, by
                  delivery of the following:

                  (i)      the delivery to the Escrow Agent of the Escrowed
                           Shares in respect of each Vendor being the number of
                           Escrowed Shares set out opposite the name of each
                           Vendor in Schedule A2;

                  (ii)     the execution and delivery by the Purchaser of a
                           Warrant in the form attached as Schedule 3.2 in
                           respect of the securities listed as options or
                           warrants on Schedule A2;

                  (iii)    the delivery to each of the Vendors of the equity
                           portion of the Purchase Price for the securities
                           listed on Schedule A2 (less the Escrowed Shares
                           delivered to the Escrow Agent pursuant to Section
                           3.2(b)(i) above) being that number of Hydrogenics
                           Shares set out opposite the name of such Vendor on
                           Schedule A2;

         (c)      in order to purchase each of the Chapman Option and the Dean
                  Option, by delivery to each of David Chapman and James Dean of
                  the following:

                  (i)      the cash consideration set out opposite his name on
                           Schedule A3; and

<PAGE>

                                     - 21 -

                  (ii)     the number of Hydrogenics Shares set forth opposite
                           his name on Schedule A3; and

         (d)      in order to exercise the Chapman Option and the Dean Option
                  and purchase the securities listed on Schedule A4, by delivery
                  to Horton Trading Ltd. of the following:

                  (i)      the cash consideration set out on Schedule A4; and

                  (ii)     the number of Hydrogenics Shares set forth on
                           Schedule A4;

and in connection with each purchase and sale provided for in this Section 3.2,
the parties acknowledge and agree that each transaction is to be carried out (to
the extent possible) in accordance with subsection 85(1) or subsection 85(2) of
the Income Tax Act (Canada) and the Purchaser agrees in respect of each
transaction that it will elect pursuant to subsection 85(1) or subsection 85(2)
of the Income Tax Act (Canada) in the prescribed form and within the time
referred to in subsection 85(6) of the Income Tax Act (Canada), at an elected
amount to be determined by the Vendor.

3.3      ESCROWED SHARES

The Escrowed Shares shall be held by the Escrow Agent as security for the
satisfaction, performance and observance by the Vendors of their several
obligations, duties and liabilities under this Agreement in accordance with the
terms of the Escrow Agreement.

3.4      INVENTORY COUNT

As soon as reasonably practicable following December 31, 2002, the Purchaser
shall count and value the Inventories as of such time. The results of the
inventory count shall be used in the preparation of the Closing Date Financial
Statement.

<PAGE>

                                     - 22 -


3.5      DELIVERY OF CLOSING DATE FINANCIAL STATEMENT

As soon as reasonably practicable after the Closing Date and in any event not
later than 45 days thereafter, the Company shall prepare in good faith and
deliver to the Vendors and the Purchaser the Closing Date Financial Statement
including a statement of the Closing Net Assets and shall cause the Auditor to
prepare and provide its audit report thereon. A draft of the Closing Date
Financial Statement shall be provided for review and discussion as soon as it is
available and in any event no later than 30 days after the Closing Date. The
Parties shall cooperate fully in the preparation of the Closing Date Financial
Statement.

3.6      ADJUSTMENTS

Unless an Objection Notice is delivered pursuant to Section 3.7, on the 31st day
after delivery by the Purchaser to the Vendors of the Closing Date Financial
Statement the following adjustments shall occur:

         (a)      if the Closing Net Assets are less than $843,000, then such
                  aggregate number of Escrowed Shares as have a value equal to
                  the amount of the difference shall be released to the
                  Purchaser in accordance with the terms of the Escrow
                  Agreement.

         (b)      if the Closing Revenue is less than $5,865,000, then such
                  aggregate number of Escrowed Shares as have a value equal to
                  the amount of the difference shall be released to the
                  Purchaser in accordance with the terms of the Escrow
                  Agreement.

For the purposes of the foregoing, each Escrowed Share released to the Purchaser
shall be valued in accordance with the terms of the Escrow Agreement.

3.7      OBJECTION TO CLOSING DATE FINANCIAL STATEMENT

         (a)      DELIVERY OF OBJECTION NOTICE - In the event that any of the
                  Vendors objects in good faith to any item of the Closing Date
                  Financial Statement, such Vendor shall so advise the Purchaser
                  by delivery to the Purchaser and the Escrow Agent of a written
                  notice (the "Objection Notice") within 30 days after the
                  delivery to the Vendors of the Closing Date Financial
                  Statement. The Objection Notice shall set

<PAGE>

                                     - 23 -

                  out the reasons for the Vendor's objection as well as the
                  amount in dispute and reasonable details of the calculation of
                  such amount. If an Objection Notice is delivered pursuant to
                  this Section 3.7 the adjustment referred to in Section 3.6
                  shall not be made except in accordance with Section 3.7.

         (b)      RESOLUTION OF DISPUTES - The Purchaser, the Company and the
                  Auditor shall give the Vendors and their accountants full
                  access to the Books and Records and work papers of the
                  Purchaser, the Company and the Auditor used in the preparation
                  of the Closing Date Financial Statement and shall have
                  reasonable access to speak to the appropriate representative
                  of each of the Purchaser, the Company and the Auditor to
                  enable each Vendor to exercise its rights under this Section.
                  The Vendors and the Purchaser shall attempt to resolve all of
                  the items in dispute set out in any Objection Notice within 30
                  days of receipt of the Objection Notice by the Purchaser and
                  the Purchaser shall instruct the Auditor to attempt to assist
                  in that resolution. Any items in dispute not resolved within
                  such 30 day period shall be referred as soon as possible
                  thereafter by the Vendors and the Purchaser to the Independent
                  Auditor. The Independent Auditor shall act as expert and not
                  as arbitrator and shall be required to determine the items in
                  dispute that have been referred to it as soon as reasonably
                  practicable but in any event not later than 30 days after the
                  date of acceptance of the engagement by the Independent
                  Auditor of the dispute to it. In making its determination, the
                  Independent Auditor will only consider the issues in dispute
                  placed before it. The Vendors and the Purchaser shall provide
                  or make available, and shall cause the Auditor to provide or
                  make available, all documents and information as are
                  reasonably required by the Independent Auditor to make its
                  determination. The determination of the Independent Auditor
                  shall be final and binding on the Parties and the Closing Date
                  Financial Statement shall be (or not be) adjusted in
                  accordance with such determination.

         (c)      AUDIT EXPENSES - The fees and expenses of the Auditor in
                  acting in accordance with this ARTICLE 3 shall be paid by the
                  Purchaser. The fees and expenses of the Independent Auditor in
                  acting in accordance with this ARTICLE 3 shall be

<PAGE>

                                     - 24 -

                  paid by the Vendor or Vendors who delivered the Objection
                  Notice, unless the Independent Auditor disagrees with the
                  Auditor such that there are changes to the Closing Date
                  Financial Statements that result in an aggregate change to the
                  adjustments pursuant to Section 3.6 of greater than 5% of the
                  total thereof, in which case the Purchaser shall pay such fees
                  and expenses.

         (d)      PAYMENT IN ACCORDANCE WITH DETERMINATION - Within five (5)
                  days after resolution, by agreement of the Parties, of the
                  dispute which was the subject of the Objection Notice or,
                  failing such resolution, within five (5) days after the final
                  determination of the Independent Auditor, the Purchaser may
                  make a claim against the Escrowed Shares in accordance with
                  the Escrow Agreement in an amount as agreed to or as
                  determined by the Independent Auditor.

3.8      DELIVERY OF CASH CONSIDERATION

The aggregate cash consideration payable to the Vendors as contemplated in
Section 3.2 shall be paid by way of wire transfer by the Purchaser on Closing to
Blake, Cassels & Graydon LLP in trust for the Vendors.

3.9      DELIVERY OF EQUITY PORTION OF PURCHASE PRICE

The delivery of the equity portion of the Purchase Price contemplated in Section
3.2 shall be made on Closing by way of direction from the Purchaser to the
Transfer Agent substantially in the form attached as Schedule 3.9 directing the
Transfer Agent to prepare share certificates with applicable legends for
delivery to Blake, Cassels & Graydon LLP in trust for the Vendors.

3.10     DELIVERY OF ESCROWED SHARES

The delivery of the Escrowed Shares shall be by way of direction from the
Purchaser to the Transfer Agent substantially in the form attached as Schedule
3.10 directing the Transfer Agent to prepare share certificates in the name of
the Escrow Agent representing the aggregate Escrowed Shares for delivery to the
Escrow Agent.

<PAGE>

                                     - 25 -

                                   ARTICLE 4

                  REPRESENTATIONS AND WARRANTIES OF THE COMPANY

The Company hereby represents and warrants to the Purchaser the matters as
provided in Schedule 4 hereto and acknowledges that the Purchaser is relying on
such representations and warranties in connection with entering into this
Agreement.

                                   ARTICLE 5

                  REPRESENTATIONS AND WARRANTIES OF THE VENDORS

Each of the Vendors hereby represents and warrants to the Purchaser the matters
as provided in Schedule 5 hereto and acknowledges that the Purchaser is relying
on such representations and warranties in connection with entering into this
Agreement.

                                   ARTICLE 6

                 REPRESENTATIONS AND WARRANTIES OF THE PURCHASER

The Purchaser hereby represents and warrants to the Vendors the matters provided
in Schedule 6 hereto and acknowledges that the Vendors are relying on such
representations and warranties in connection with entering into this Agreement.

                                   ARTICLE 7

                              NON-WAIVER; SURVIVAL

7.1      NON-WAIVER

No investigations made by or on behalf of the Purchaser at any time shall have
the effect of waiving, diminishing the scope or otherwise affecting any
representation or warranty made by the Vendors in or pursuant to this Agreement.
No waiver of any condition or other provisions, in whole or in part, shall
constitute a waiver of any other condition or provision (whether or not similar)
nor shall such waiver constitute a continuing waiver unless otherwise expressly
provided.

<PAGE>

                                     - 26 -

7.2      NATURE AND SURVIVAL

         (a)      Subject to subsection (b), all representations, warranties and
                  covenants contained in this Agreement on the part of each of
                  the Parties shall survive the Closing, the execution and
                  delivery under this Agreement of any share or security
                  transfer instruments or other documents of title to any of the
                  Purchased Securities and the payment of the consideration for
                  the Purchased Securities.

         (b)      Representations and warranties of the Vendors, relating to
                  "Right to Sell" set out in Section 2 of Schedule 5, and the
                  representation and warranty of the Purchaser relating to the
                  valid issuance of the Hydrogenics Shares set out in Section
                  2(b) of Schedule 6 shall survive indefinitely. Representations
                  and warranties of the Company shall survive until the
                  expiration of the period for the Purchaser to bring any claims
                  for indemnity as set out in Section 9.3. All other
                  representations and warranties shall only survive for a period
                  of 24 months from the Closing Date. If no claim shall have
                  been made under this Agreement against a Party for any
                  incorrectness in or breach of any representation or warranty
                  made in this Agreement prior to the expiry of these survival
                  periods, such Party shall have no further liability under this
                  Agreement with respect to such representation or warranty.

         (c)      Notwithstanding the limitations set out in subsection (b), any
                  Claim which is based on title to the Purchased Securities,
                  intentional misrepresentation or fraud may be brought at any
                  time.

                                   ARTICLE 8

                         OTHER COVENANTS OF THE PARTIES

8.1      CONTRACTUAL HOLD PERIODS

         (a)      Subject to paragraph (b) below, none of the Vendors shall,
                  directly or indirectly, sell any of the Hydrogenics Shares,
                  except as follows:

<PAGE>

                                     - 27 -

                  (i)      each Vendor may sell up to 50% of the Hydrogenics
                           Shares issued to such Vendor following the expiry of
                           a period of 12 months from the Effective Date; and

                  (ii)     each Vendor may sell the remaining 50% of the
                           Hydrogenics Shares issued to such Vendor following
                           the expiry of 18 months from the Effective Date.

         (b)      The Vendors may also sell the Hydrogenics Shares as follows:

                  (i)      after the expiry of four months from the Effective
                           Date, each of Horton Trading Ltd. and Ventures West
                           may each sell on the TSX up to 40,000 Hydrogenics
                           Shares in any 30 day period provided that such
                           Hydrogenics Shares are sold in blocks of not less
                           than 10,000 shares at a price that is greater than or
                           equal to 100% of the closing price of Hydrogenics
                           Shares on the TSX on the trading day prior to such
                           sale;

                  (ii)     after the expiry of four months from the Effective
                           Date, the Key Executives in the aggregate may sell on
                           the TSX up to 40,000 Hydrogenics Shares in any 30 day
                           period provided that such Hydrogenics Shares are sold
                           in blocks of not less than 8,000 shares at a price
                           that is greater than or equal to 100% of the closing
                           price of Hydrogenics Shares on the TSX on the trading
                           day prior to such sale; and

                  (iii)    Horton Trading Ltd. and Ventures West may sell
                           Hydrogenics Shares in excess of the limitations set
                           out in (ii) above with the prior written consent of
                           the Purchaser, such approval not to be unreasonably
                           withheld, and the Purchaser shall make commercially
                           reasonable efforts to respond in a timely way to all
                           such requests;

                  in which case any Hydrogenics Shares sold shall be equally
                  divided and sold from the Hydrogenics Shares subject to the 12
                  and 18 month hold periods set forth in clauses 8.1 (a)(i) and
                  (ii).

<PAGE>

                                     - 28 -

         (c)      The Vendors understand and acknowledge that upon the original
                  issuance thereof, and until such time as the same is no longer
                  required under applicable requirements of the U.S. Securities
                  Act or applicable state securities laws, certificates
                  representing Hydrogenics Shares acquired by each of them
                  pursuant to this Agreement, the Warrants, the Chapman Option
                  or the Dean Option, as the case may be, and all certificates
                  issued in exchange therefor or in substitution thereof, shall
                  bear a legend substantially in the following form:

                  "THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED
                  UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED
                  (THE "SECURITIES ACT") OR THE SECURITIES LAWS OF ANY STATE.
                  THE HOLDER HEREOF, BY PURCHASING SUCH SECURITIES, AGREES FOR
                  THE BENEFIT OF THE COMPANY THAT SUCH SECURITIES MAY BE
                  OFFERED, SOLD OR OTHERWISE TRANSFERRED ONLY (A) TO THE
                  COMPANY, (B) OUTSIDE THE UNITED STATES IN COMPLIANCE WITH RULE
                  904 OF REGULATION S UNDER THE SECURITIES ACT, (C) IN
                  COMPLIANCE WITH RULE 144 OR RULE 144A UNDER THE SECURITIES
                  ACT, IF AVAILABLE, OR (D) IN COMPLIANCE WITH ANOTHER EXEMPTION
                  FROM REGISTRATION UNDER THE SECURITIES ACT AND APPLICABLE
                  STATE SECURITIES LAWS, PROVIDED THE COMPANY HAS RECEIVED AN
                  OPINION OF COUNSEL OF RECOGNIZED STANDING IN FORM AND
                  SUBSTANCE SATISFACTORY TO THE COMPANY THAT REGISTRATION IS NOT
                  REQUIRED. DELIVERY OF THIS CERTIFICATE MAY NOT CONSTITUTE
                  "GOOD DELIVERY" IN SETTLEMENT OF TRANSACTIONS ON STOCK
                  EXCHANGES IN CANADA. PROVIDED THAT THE COMPANY IS A "FOREIGN
                  ISSUER" WITHIN THE MEANING OF REGULATION S AT THE TIME OF
                  SALE, A

<PAGE>

                                     - 29 -

                  NEW CERTIFICATE, BEARING NO LEGEND, DELIVERY OF WHICH WILL
                  CONSTITUTE "GOOD DELIVERY" MAY BE OBTAINED FROM CIBC MELLON
                  TRUST COMPANY UPON DELIVERY OF THIS CERTIFICATE AND A DULY
                  EXECUTED DECLARATION, IN A FORM SATISFACTORY TO CIBC MELLON
                  TRUST COMPANY AND THE COMPANY, TO THE EFFECT THAT THE SALE OF
                  THE SECURITIES REPRESENTED HEREBY IS BEING MADE IN COMPLIANCE
                  WITH RULE 904 OF REGULATION S UNDER THE SECURITIES ACT.";

                  provided, that if the securities are being sold in compliance
                  with Rule 904 of Regulation S, and provided that the Purchaser
                  is a "foreign issuer" within the meaning of Regulation S at
                  the time of sale, the legend may be removed by providing a
                  declaration to the registrar and transfer agent for such
                  securities, as set forth in Schedule 8.1 hereto (or as the
                  Purchaser may prescribe from time to time); and provided,
                  further that, if any such securities are being sold under Rule
                  144 or Rule 144A under the U.S. Securities Act, the legend may
                  be removed by delivery to the registrar and transfer agent of
                  the securities of an opinion of counsel of recognized standing
                  reasonably satisfactory to the Purchaser, that such legend is
                  no longer required under applicable requirements of the U.S.
                  Securities Act or applicable state securities laws;

                  The Purchaser shall remove, and/or cause the transfer agent
                  for the security to which the written declaration or opinion
                  referred to in the legend above relates to remove, the legend
                  where such written declaration or opinion is delivered to it
                  or the transfer agent. The Purchaser and the transfer agent
                  shall be entitled to rely on the representations and warranty
                  in the written declaration that Rule 904 of Regulation S is
                  being appropriately relied upon.

         (d)      The Vendors also understand and acknowledge that upon the
                  original issuance thereof, and until such time as the same is
                  no longer required under applicable requirements of applicable
                  securities laws, certificates representing Hydrogenics

<PAGE>

                                     - 30 -

                  Shares acquired by such Vendors pursuant to this Agreement,
                  the Warrants, the Chapman Option or the Dean Option, as the
                  case may be, and all certificates issued in exchange therefor
                  or in substitution thereof, shall bear a legend substantially
                  in the following form:

                  "UNLESS PERMITTED UNDER APPLICABLE CANADIAN SECURITIES
                  LEGISLATION, THE HOLDER OF THE SECURITIES SHALL NOT TRADE THE
                  SECURITIES BEFORE MAY 8, 2003."

         (e)      Each of the Vendors understands and acknowledges that upon the
                  original issuance thereof, and until such time as the same is
                  no longer required under applicable requirements of applicable
                  securities laws, certificates representing 50% of the
                  Hydrogenics Shares acquired by such Vendors pursuant to this
                  Agreement, the Warrants, the Chapman Option or the Dean
                  Option, as the case may be, and all certificates issued in
                  exchange therefor or in substitution thereof, shall bear a
                  legend substantially in the following form:

                  "PURSUANT TO AN AGREEMENT MADE AS OF JANUARY 7, 2003 BETWEEN
                  HYDROGENICS CORPORATION AND THE HOLDER HEREOF (THE
                  "AGREEMENT"), THE SECURITIES REPRESENTED BY THIS CERTIFICATE
                  MAY NOT BE SOLD BY THE HOLDER HEREOF PRIOR TO JANUARY 7, 2004
                  EXCEPT AS OTHERWISE PERMITTED UNDER THE AGREEMENT."

         (f)      Each of the Vendors understands and acknowledges that upon the
                  original issuance thereof, and until such time as the same is
                  no longer required under of applicable securities laws,
                  certificates representing 50% of the Hydrogenics Shares
                  acquired by such Vendors pursuant to this Agreement, the
                  Warrants, the Chapman Option or the Dean Option, as the case
                  may be, and all certificates issued in exchange therefor or in
                  substitution thereof, shall bear a legend substantially in the
                  following form:

<PAGE>

                                     - 31 -

                  "PURSUANT TO AN AGREEMENT MADE AS OF JANUARY 7, 2003 BETWEEN
                  HYDROGENICS CORPORATION AND THE HOLDER HEREOF (THE
                  "AGREEMENT"), THE SECURITIES REPRESENTED BY THIS CERTIFICATE
                  MAY NOT BE SOLD BY THE HOLDER HEREOF PRIOR TO JULY 7, 2004
                  EXCEPT AS OTHERWISE PERMITTED UNDER THE AGREEMENT."

         (g)      Upon expiry of the contractual hold periods described above,
                  the Hydrogenics Shares issued to the Vendors will be freely
                  tradeable in Canada.

         (h)      The Purchaser shall make commercially reasonable efforts to
                  respond in a timely way, and shall make all commercially
                  reasonably efforts as are in its control to cause the Transfer
                  Agent of the Hydrogenics Shares to respond in a timely way, to
                  any request to remove from a share certificate either of the
                  legends described in (e) or (f) to facilitate any sale of
                  Hydrogenics Shares pursuant to (a) or (b).

8.2      CLOSING DOCUMENTATION

All documentation relating to the due authorization and completion of the sale
and purchase of the Purchased Securities under this Agreement and all actions
and proceedings taken on or prior to the Closing in connection with the
performance by the Parties of their respective obligations under this Agreement,
substantially as set forth in the Closing Agenda, or other evidence as may be
reasonably requested in order to establish the consummation of the transactions
contemplated by this Agreement and the taking of all corporate proceedings in
connection with such transactions shall be provided at the Closing Time.

8.3      CONFIDENTIALITY

         (a)      After the Closing, each Vendor shall keep confidential all
                  Personal Information it disclosed to the Purchaser and all
                  information relating to the Company, except information (other
                  than Personal Information) which:

                  (i)      is part of the public domain;

<PAGE>

                                     - 32 -

                  (ii)     becomes part of the public domain other than as a
                           result of a breach of these provisions by the
                           Vendors;

                  (iii)    was received in good faith after Closing from an
                           independent Person who was lawfully in possession of
                           such information free of any obligation of
                           confidence;

                  (iv)     is released from the provisions of this Agreement by
                           the written authorization of Purchaser;

                  (v)      is required to be disclosed by any Laws or
                           Governmental Authority;

                  (vi)     is disclosed in connection with any litigation
                           between the Parties;

                  (vii)    is disclosed by the Party in connection with
                           establishing any defence to any Claim; or

                  (viii)   is disclosed by Ventures West to any of its limited
                           partners.

         (b)      At all times, each of the Vendors and the Purchaser shall keep
                  confidential all information disclosed to it, or to a third
                  party in connection with this transaction, by or on behalf of
                  the other Party relating to the other Party, except
                  information which:

                  (i)      is part of the public domain;

                  (ii)     becomes part of the public domain other than as a
                           result of breach of these provisions;

                  (iii)    can be demonstrated to have been known or available
                           to them before receipt of such information from the
                           other Party or independently developed by them;

<PAGE>

                                     - 33 -

                  (iv)     was received in good faith from an independent
                           Person, who was lawfully in possession of such
                           information free of any obligation of confidence;

                  (v)      is required to be disclosed by any Laws or
                           Governmental Authority;

                  (vi)     is disclosed in connection with any litigation
                           between the Parties;

                  (vii)    is disclosed by the Party in connection with
                           establishing any defence to any Claim; or

                  (viii)   is disclosed by Ventures West to any of its limited
                           partners.

8.4      PRESERVATION OF RECORDS

The Purchaser shall take all reasonable steps to preserve and keep the records
of the Company delivered to it in connection with the completion of the
transactions contemplated by this Agreement for a period of seven (7) years from
the Closing Date, or for any longer period as may be required by any Laws or
Governmental Authority, and shall make such records available to the Vendors as
may be reasonably required by them in connection with a Claim by any Person,
including the Purchaser against the Vendors relating to this Agreement or the
transactions contemplated herein. The Vendors acknowledge that the Purchaser
shall not be liable to the Vendors in the event of any accidental destruction of
such records, caused otherwise than by the gross negligence of the Purchaser.

8.5      STUB PERIOD RETURNS

The Purchaser shall cause the Company to duly and timely make or prepare all Tax
Returns required to be made or prepared by it and to duly and timely file all
Tax Returns required to be filed by it for any period which ends on or before
the Closing Date and for which Tax Returns have not been filed as of such date.
The Purchaser shall cause the Company to make the election referred to in
subsection 256(9) of the Income Tax Act (Canada), and comparable provisions of
applicable provincial legislation, and to file such election(s) for the
Company's taxation year(s) ending immediately before the Closing Time. The
Purchaser shall also cause the Company to duly and timely make or prepare all
Tax Returns required to be made or prepared by it and to

<PAGE>

                                     - 34 -

duly and timely file all Tax Returns required to be filed by it for periods
beginning before and ending after the Closing Date. The Vendors and the
Purchaser shall co-operate fully with each other and make available to each
other in a timely fashion such data and other information as may reasonably be
required for the preparation of any Tax Return of the Company for a period
ending on, prior to or including the Closing Date and shall preserve such data
and other information until the expiration of any applicable limitation period
under any applicable law with respect to Taxes.

8.6      CONSENT TO JURISDICTION

         (a)      Each of the Parties irrevocably attorns and submits to the
                  jurisdiction of any Ontario court sitting in Toronto in any
                  action or proceeding arising out of or related to this
                  Agreement and irrevocably agrees that all claims in respect of
                  any such action or proceeding may be heard and determined in
                  such Ontario court. Each of the Parties irrevocably waives, to
                  the fullest extent it may effectively do so, the defence of an
                  inconvenient forum to the maintenance of such action or
                  proceeding. A final judgment in any such action or proceeding
                  shall be conclusive and may be enforced in other jurisdictions
                  by suit on the judgment or in any other manner provided by
                  law.

         (b)      Nothing in this section shall affect the right of the Parties
                  to bring any action or proceeding against the other Parties or
                  its property in the courts of any other jurisdiction.

8.7      SECURITIES EXEMPTIONS

Each Vendor acknowledges and agrees that no prospectus has been prepared or
filed by the Purchaser with any securities commission or similar authority in
connection with the delivery of the Hydrogenics Shares in consideration for the
Purchased Securities and that such delivery is conditional upon the transaction
not being subject to, or being exempt from, the prospectus filing requirements
of all applicable securities legislation relating to the sale of such
Hydrogenics Shares. As a result, each Vendor acknowledges that it may be
restricted from using most of the civil remedies available under applicable
securities laws and that the Purchaser may be relieved

<PAGE>

                                     - 35 -

from certain obligations that would otherwise apply if a prospectus was provided
under applicable securities laws in connection with the delivery of the
Hydrogenics Shares. Each Vendor shall be solely responsible (and the Purchaser
will in no way be responsible) for compliance with all relevant securities
legislation, regulations and policies concerning any resale of the Hydrogenics
Shares.

8.8      WITHHOLDING TAX

         (a)      VW7US shall take reasonable steps to obtain and deliver to the
                  Purchaser a certificate issued by the Minister of National
                  Revenue under subsection 116(2) or 116(4) of the Income Tax
                  Act (Canada).

         (b)      If a certificate is delivered to the Purchaser on or before
                  the Closing Date, the Purchaser shall be entitled to withhold
                  from the portion of the Purchase Price payable to VW7US 25% of
                  the amount (the "Deficiency Amount"), if any, by which such
                  portion of the Purchase Price exceeds the certificate limit as
                  defined in subsection 116(2) of the Income Tax Act (Canada)
                  and fixed by the Minister of National Revenue in such
                  certificate. The Purchaser shall withhold first from cash
                  otherwise payable to VW7US and then from Hydrogenics Shares as
                  to the balance thereof.

         (c)      If a certificate is not delivered on or before the Closing
                  Date, the Purchaser shall be entitled to withhold 50% of the
                  portion of the Purchase Price otherwise payable to VW7US. The
                  Purchaser shall withhold first from cash otherwise payable to
                  VW7US and then from Hydrogenics Shares as to the balance
                  thereof.

         (d)      If the Purchaser has withheld any amount under the provisions
                  of paragraphs (b) or (c) above and VW7US delivers to the
                  Purchaser, after the Closing Date and within 25 days after the
                  end of the month in which the Closing Date occurs, or such
                  later date as is consented to in writing by the Canada Customs
                  and Revenue Agency, such written consent being referred to
                  herein as a "Comfort Letter", a certificate issued by the
                  Minister of National Revenue under subsection 116(2) or 116(4)
                  of the Income Tax Act (Canada), with a certificate limit or
                  proceeds of

<PAGE>

                                     - 36 -

                  disposition fixed thereon equal to or greater than such
                  portion of the Purchase Price payable to VW7US, then the
                  Purchaser shall pay or release forthwith to VW7US any amount
                  that the Purchaser has withheld and the amount so paid or
                  released shall be credited to the Purchaser as payment on
                  account of the Purchase Price.

         (e)      If the Purchaser has withheld any amount under the provisions
                  of paragraphs (b) or (c) above and no certificate or Comfort
                  Letter has been delivered to the Purchaser by VW7US in
                  accordance with the provisions of paragraph (d) above, then
                  VW7US shall pay in Canadian dollars to the Purchaser on the
                  25th day after the end of the month in which the Closing Date
                  occurs an amount equal to 25% of the Deficiency Amount or the
                  Purchase Price, as applicable, less any cash proceeds withheld
                  by the Purchaser. The Purchaser shall forthwith release to
                  VW7US the Hydrogenics Shares withheld under this Section 8.8
                  which payment shall be credited to the Purchaser as payment on
                  account of the portion of the Purchase Price payable to VW7US
                  and pay the cash withheld and the cash received to the
                  Receiver General not later than the 30th day after the end of
                  the month in which the Closing occurs on account of the
                  Purchaser's liability pursuant to subsection 116(5) of the
                  Income Tax Act (Canada) and the withheld cash so paid to the
                  Receiver General shall be credited to the Purchaser as payment
                  on account of the portion of the Purchase Price payable to
                  VW7US.

         (f)      If the Purchaser has withheld any amount under the provisions
                  of paragraphs (b) or (c) above, a Comfort Letter has been
                  provided and no certificate has been delivered to the
                  Purchaser by VW7US in accordance with the provisions of
                  paragraph (d) above prior to the expiry of such Comfort
                  Letter, then VW7US shall pay in Canadian dollars to the
                  Purchaser on the expiry date of such Comfort Letter an amount
                  equal to 25% of the Deficiency Amount or the Purchase Price,
                  as applicable, less any cash proceeds withheld by the
                  Purchaser. The Purchaser shall forthwith release to VW7US the
                  Hydrogenics Shares withheld under this Section 8.8 which
                  payment shall be credited to the Purchaser as payment on
                  account of the portion of the Purchase Price payable to VW7US
                  and pay the cash

<PAGE>

                                     - 37 -

                  withheld and the cash received to the Receiver General not
                  later than the date required by such Comfort Letter (or by a
                  letter revoking or terminating such Comfort Letter) on account
                  of the Purchaser's liability pursuant to subsection 116(5) of
                  the Income Tax Act (Canada) and the withheld cash so paid to
                  the Receiver General shall be credited to the Purchaser as
                  payment on account of the portion of the Purchase Price
                  payable to VW7US.

         (g)      If VW7US has not made the payment required pursuant to the
                  provisions of paragraphs (e) or (f) above, the Purchaser may,
                  at its option, on behalf of VW7US, liquidate any Hydrogenics
                  Shares withheld in accordance with this Section 8.8 at the
                  expense of VW7US (to the extent such expense is reasonable) in
                  order to make any of the payments to the Receiver General
                  described in this Section 8.8, provided that (i) the Purchaser
                  may liquidate Hydrogenics Shares withheld by it only to the
                  extent that the cash withheld by it is insufficient to make
                  any of the payments to the Receiver General described in this
                  section, (ii) the Purchaser shall use reasonable efforts to
                  obtain a reasonable arm's length price for such Hydrogenics
                  Shares and (iii) VW7US will indemnify the Purchaser for any
                  shortfall in the event the proceeds from liquidation are
                  insufficient to make required payments to the Receiver
                  General. Any net liquidation proceeds shall be deemed to be
                  withheld cash for purposes of paragraph (e) or (f) above.

         (h)      All amounts and Hydrogenics Shares withheld by the Purchaser
                  in accordance with this clause shall be paid to and held by
                  Osler, Hoskin & Harcourt LLP, in trust, and any cash portion
                  thereof shall be invested in such manner as VW7US shall from
                  time to time direct in writing until paid to VW7US or the
                  Receiver General in accordance with this Section 8.8 All
                  interest earned on any amounts held by Osler, Hoskin &
                  Harcourt LLP shall be for the account of VW7US. Osler, Hoskin
                  & Harcourt LLP shall be entitled to withhold from interest
                  earned on such amounts any and all amounts required to be
                  withheld and remitted from such interest by any Law and to
                  remit same to the appropriate Governmental Authority. All
                  interest earned, other than amounts required to be withheld
                  and

<PAGE>

                                     - 38 -

                  remitted from such interest by any Law, shall be paid to VW7US
                  concurrently with the payment of any other amounts to VW7US or
                  the Receiver General.

8.9      CONTINUED LISTING ON TSX

The Purchaser covenants and agrees with the Vendors that, until such time as all
of the Hydrogenics Shares issued to the Vendors hereunder are freely-tradeable
in the United States and the Purchaser, at its own cost and expense, has caused
the removal of the legend set forth in Section 8.1(c) from Hydrogenics Shares,
as applicable, the Purchaser shall take all commercially reasonable steps under
its control to ensure Hydrogenics Shares will remain listed on the Toronto Stock
Exchange. Notwithstanding the foregoing, this covenant shall no longer apply in
the event that a Person acquires by any means more than 90% of the issued and
outstanding Hydrogenics Shares. For greater certainty, the foregoing shall not
require the Purchaser to pay for the removal of a legend set forth in Section
8.1(c) from Hydrogenics Shares if such removal is required by the Vendor under
Section 8.1(c).

8.10     OFFER TO MINOR VENDORS

The Purchaser covenants and agrees that as soon as practicable after closing it
will make an offer to all securityholders of the Company to purchase their
securities on substantially the same terms set forth herein.

                                   ARTICLE 9

                                 INDEMNIFICATION

9.1      INDEMNIFICATION BY THE VENDORS

Subject to the limitations as to amount set out below, each of the Vendors shall
indemnify and save harmless the Purchaser, its directors, officers, agents,
employees and shareholders (in this Section collectively referred to as the
"Indemnified Parties") on an after-Tax basis, from and against all Claims which
may be made or brought against the Indemnified Parties, or which they may suffer
or incur, directly or indirectly as a result of or in connection with:

<PAGE>

                                     - 39 -

         (a)      any incorrectness or breach of any representation or warranty
                  of the Company contained in this Agreement;

         (b)      any non-fulfilment of any covenant or agreement on the part of
                  such Vendor under this Agreement; or

         (c)      any incorrectness in or breach of any representation or
                  warranty of such Vendor contained in this Agreement.

9.2      INDEMNIFICATION BY THE PURCHASER

The Purchaser shall indemnify and save harmless the Vendors, their directors,
officers, employees, agents (in this section collectively referred to as the
"Indemnified Parties"), on an after-Tax basis, from and against all Claims which
may be made or brought against the Indemnified Parties, or which they may suffer
or incur, directly or indirectly as a result of or in connection with:

         (a)      any non-fulfilment of any covenant or agreement on the part of
                  the Purchaser under this Agreement;

         (b)      any incorrectness in or breach of any representation or
                  warranty of the Purchaser contained in this Agreement.

9.3      LIMITATION PERIODS

The obligation of indemnification set out in Section 9.1 above shall apply only
to Claims brought by the Purchaser as follows:

         (a)      Claims made pursuant to Section 9.1(a) may be brought:

                  (i)      at any time in respect of Claims based on
                           representations or warranties of the Company relating
                           to Environmental matters set out in Section 31 of
                           Schedule 4 or Competition Act Assets and Revenues in
                           Section 10 of Schedule 4;

<PAGE>

                                     - 40 -

                  (ii)     within 90 days after the relevant authorities shall
                           no longer be entitled to assess liability against the
                           Company in respect of Claims based on representations
                           or warranties of the Company relating to or impacted
                           by Tax matters, including those set out in Section 40
                           of Schedule 4 arising in or in respect of a
                           particular period ending on, before or including the
                           Effective Date; or

                  (iii)    within 24 months of the Closing Date in respect of
                           any other Claims based on representations or
                           warranties of the Company.

         (b)      Claims made pursuant to Sections 9.1(b) or 9.1(c) above shall
                  be subject to the limitations contained in Section 7.2
                  respecting the survival of the representations and warranties.

         (c)      Claims made pursuant to Section 9.2 shall be subject to the
                  limitations contained in Section 7.2 respecting the survival
                  of the representations and warranties.

9.4      LIMITATIONS ON INDEMNIFICATION OBLIGATIONS

         (a)      In respect of Claims made by the Purchaser pursuant to Section
                  9.1(a):

                  (i)      the liability of each of the Vendors in relation to
                           any such Claim shall extend only to such Vendor's
                           Proportionate Share of the aggregate liability under
                           such Claim;

                  (ii)     the aggregate liability of each of the Vendors for
                           all Claims under Section 9.1(a) shall not exceed an
                           amount equal to such Vendor's Proportionate Share of
                           20% of the Purchase Price; and

                  (iii)    none of the Vendors shall be required to pay any
                           amount in respect of any such Claims until the
                           aggregate amount of all such Claims against Vendors
                           exceeds $100,000 and, subject to the limitations set
                           out in (i) and (ii) above, upon the aggregate amount
                           of such Claims against Vendors

<PAGE>

                                     - 41 -

                           exceeding $100,000 each of the Vendors shall be
                           required to pay the full amount or the full amount of
                           their Proportionate Share, as applicable, in respect
                           of all of such Claims.

         (b)      The aggregate liability of each of the Vendors for all Claims
                  pursuant to Section 9.1 shall not exceed such Vendor's
                  Proportionate Share of the Purchase Price.

         (c)      The aggregate liability of the Purchaser to each of the
                  Vendors for all Claims pursuant to Section 9.2 shall not
                  exceed such Vendor's Proportionate Share of the Purchase
                  Price.

         (d)      The limitations provided under Section 9.4(a) shall not apply
                  to any Claims based on intentional misrepresentation or fraud
                  except that:

                  (i)      the liability of Ventures West for any Claim based on
                           intentional misrepresentation or fraud of the Company
                           shall not exceed their Proportionate Share of 20% of
                           the Purchase Price except to the extent they were
                           aware or had knowledge of such intentional
                           misrepresentation or fraud; and

                  (ii)     Each of David Chapman and James Dean's liability for
                           any Claim based on intentional misrepresentation or
                           fraud of the Company shall not exceed his
                           Proportionate Share of 20% of the Purchase Price
                           unless he was aware or had knowledge of such
                           intentional misrepresentation or fraud or it relates
                           to matters which occurred while he was employed by
                           the Company.

         (e)      The Purchaser's sole recourse for Claims made pursuant to
                  Section 9.1(a) against each Vendor shall be limited to the
                  Escrowed Shares owned by such Vendor while such Escrowed
                  Shares are held by the Escrow Agent. For further
                  clarification, the Purchaser may not seek any recourse against
                  any of the consideration paid to such Vendor other than the
                  Escrowed Shares while such

<PAGE>

                                     - 42 -

                  Escrowed Shares are held by the Escrow Agent nor any other
                  assets of the Vendor;

         (f)      Garry Piotrowski and the Piotrowski Family Trust shall be
                  jointly and severally liable for all Claims made against
                  either of them pursuant to Section 9.1;

         (g)      Garry Sedun and the Sedun Family Trust shall be jointly and
                  severally liable for all Claims made against either of them
                  pursuant to Section 9.1.

9.5      INDEMNIFICATION PROCEDURES FOR THIRD PARTY CLAIMS

         (a)      In the case of Claims made by a third party with respect to
                  which indemnification is sought, the Party seeking
                  indemnification (in this Section, the "Indemnified Party")
                  shall give prompt notice, and in any event within 20 days, to
                  the other Party (in this Section, the "Indemnifying Party") of
                  any such Claims made upon it. If the Indemnifying Party fails
                  to give such notice, such failure shall not preclude the
                  Indemnified Party from obtaining such indemnification but its
                  right to indemnification may be reduced to the extent that
                  such delay prejudiced the defence of the Claim or increased
                  the amount of liability or cost of defense and provided that
                  no claim for indemnity in respect of the breach of any
                  representation or warranty contained in this Agreement may be
                  made unless notice of such Claim has been given prior to the
                  expiry of the survival period applicable to such
                  representation and warranty pursuant to Section 7.2.

         (b)      The Indemnifying Party shall have the right, by notice to the
                  Indemnified Party given not later than 30 days after receipt
                  of the notice described in subsection (a), to assume the
                  control of the defence, compromise or settlement of the Claim,
                  provided that such assumption shall, by its terms, be without
                  cost to the Indemnified Party and provided the Indemnifying
                  Party acknowledges in writing its obligation to indemnify the
                  Indemnified Party in accordance with the terms contained in
                  this Section in respect of that Claim.

<PAGE>

                                     - 43 -

         (c)      Upon the assumption of control of any Claim by the
                  Indemnifying Party as set out in subsection (b), the
                  Indemnifying Party shall diligently proceed with the defence,
                  compromise or settlement of the Claim at its sole expense,
                  including if necessary, employment of counsel reasonably
                  satisfactory to the Indemnified Party and, in connection
                  therewith, the Indemnified Party shall co-operate fully, but
                  at the expense of the Indemnifying Party with respect to any
                  out-of-pocket expenses incurred, to make available to the
                  Indemnifying Party all pertinent information and witnesses
                  under the Indemnified Party's control, make such assignments
                  and take such other steps as in the opinion of counsel for the
                  Indemnifying Party are reasonably necessary to enable the
                  Indemnifying Party to conduct such defence. The Indemnified
                  Party shall also have the right to participate in the
                  negotiation, settlement or defence of any Claim at its own
                  expense.

         (d)      The final determination of any Claim pursuant to this Section,
                  including all related costs and expenses, shall be binding and
                  conclusive upon the Parties as to the validity or invalidity,
                  as the case may be, of such Claim against the Indemnifying
                  Party.

         (e)      If the Indemnifying Party does not assume control of a Claim
                  as permitted in subsection (b), the Indemnified Party shall be
                  entitled to make such settlement of the Claim as in its sole
                  discretion may appear advisable, and such settlement or any
                  other final determination of the Claim shall be binding upon
                  the Indemnifying Party.

9.6      TAX STATUS OF INDEMNIFICATION PAYMENTS

Any payment made by the Vendors as an Indemnifying Party pursuant to this
ARTICLE 9 shall constitute a reduction of the Purchase Price and any payment
made by the Purchaser as an Indemnifying Party pursuant to this ARTICLE 9 shall
constitute an increase in the Purchase Price. In either case, each of the
Vendors and the Purchaser shall, within a reasonable time of payment and receipt
of such payment, as applicable, and in any event within two (2) months of

<PAGE>

                                     - 44 -

such payment, request all amendments to its current or past Tax Returns as may
be necessary to reflect the foregoing.

9.7      ESCROWED SHARES

For so long as the Escrowed Shares remain in escrow, upon notice to the Vendors
of any Claim pursuant to Section 9.1 the Purchaser may make a claim against the
Escrowed Shares in accordance with the Escrow Agreement. Subject to Section
9.4(e), neither the exercise nor failure to exercise such right shall constitute
an election of remedies or limit the remedies available to the Purchaser in the
enforcement of its rights under this Agreement.

                                   ARTICLE 10

                                     GENERAL

10.1     PUBLIC NOTICES

The Parties shall jointly plan and co-ordinate any public notices, press
releases, and any other publicity concerning the transactions contemplated by
this Agreement and no Party shall act in this regard without the prior approval
of the other, such approval not to be unreasonably withheld unless such
disclosure is required to meet timely disclosure obligations of any Party under
applicable Laws and stock exchange rules in circumstances where prior
consultation with the other Party is not practicable and a copy of such
disclosure is provided to the other Party.

10.2     EXPENSES

Except as otherwise provided in this Agreement, each Party shall pay all costs
and expenses (including the fees and disbursements of legal counsel and other
advisers) it incurs in connection with the negotiation, preparation and
execution of this Agreement and the transactions contemplated by this Agreement,
except that the Purchaser shall pay, or cause the Company to pay, the Company's
Transaction Expenses, up to an aggregate maximum amount of $700,000.

10.3     NOTICES

Any notice, consent or approval required or permitted to be given in connection
with this Agreement (in this Section referred to as a "NOTICE") shall be in
writing and shall be sufficiently

<PAGE>

                                     - 45 -

given if delivered (whether in person, by courier service or other personal
method of delivery), or if transmitted by facsimile:

         (a)      in the case of a Notice to the Vendors at the address set out
                  for each Vendor in Schedule 10.3:

         (b)      in the case of a Notice to the Purchaser at:

                  Hydrogenics Corporation
                  5985 McLaughlin Road
                  Mississauga, Ontario L5R 1B8

                  Attention: Jonathan Lundy
                  Fax:       (905) 361-3626

                  with a copy to

                  Osler, Hoskin & Harcourt LLP
                  Box 50
                  First Canadian Place
                  Toronto, Ontario M5X 1B8

                  Attention: Mark Trachuk
                  Fax:       (416) 862-6666

         (c)      in the case of Notice to the Company:

                  Greenlight Power Technologies, Inc.
                  Unit C-4242 Phillips Avenue
                  Burnaby, British Columbia V5A 2X2

                  Attention: President
                  Fax:       (604) 676-4111

                  with a copy to

                  Blake, Cassels & Graydon LLP
                  Suite 2600, Three Bentall Centre
                  Box 49314
                  Vancouver, British Columbia V7X 1L3

                  Attention: Geoff Belsher
                  Fax:       (604) 631-3309

<PAGE>

                                     - 46 -

Any Notice delivered or transmitted to a Party as provided above shall be deemed
to have been given and received on the day it is delivered or transmitted,
provided that it is delivered or transmitted on a Business Day prior to 5:00
p.m. local time in the place of delivery or receipt. However, if the Notice is
delivered or transmitted after 5:00 p.m. local time or if such day is not a
Business Day then the Notice shall be deemed to have been given and received on
the next Business Day.

Any Party may, from time to time, change its address by giving Notice to the
other Parties in accordance with the provisions of this Section.

10.4     INTEREST ACT DISCLOSURE

For purposes of disclosure under the Interest Act (Canada), the equivalent
yearly rate of interest for any rate of interest calculated under this Agreement
on any basis other than a full calendar year, may be determined by multiplying
such rate by a fraction the numerator of which is the number of days in the
calendar year and the denominator of which is the number of days comprising such
other basis.

10.5     ASSIGNMENT

No party may assign this Agreement or any rights or obligations under this
Agreement without the prior written consent of each of the other Parties.

10.6     ENUREMENT

This Agreement shall enure to the benefit of and be binding upon the Parties and
their respective successors (including any successor by reason of amalgamation
of any Party), executors, administrators and permitted assigns.

10.7     AMENDMENT

No amendment, supplement, modification or waiver or termination of this
Agreement and, unless otherwise specified, no consent or approval by any Party,
shall be binding unless executed in writing by the Party to be bound thereby.

<PAGE>

                                     - 47 -

10.8     FURTHER ASSURANCES

The Parties shall, with reasonable diligence, do all such things and provide all
such reasonable assurances as may be required to consummate the transactions
contemplated by this Agreement, and each Party shall provide such further
documents or instruments required by any other Party as may be reasonably
necessary or desirable to effect the purpose of this Agreement and carry out its
provisions, whether before or after the Closing.

10.9     INDEPENDENT LEGAL ADVICE

Each Vendor acknowledges and agrees that Blake, Cassels & Graydon LLP is acting
solely as counsel to the Company and is not counsel to, nor has it or will it
give any advice to, such Vendor with respect to this Agreement or the
transactions contemplated by this Agreement. Such Vendor also acknowledges and
agrees that the Company has recommended that the Vendor obtain independent legal
advice with respect to this Agreement and the transactions contemplated by this
Agreement.

10.10    ATTORNMENT

For the purpose of all legal proceedings this Agreement will be deemed to have
been performed in the Province of Ontario and the courts of the Province of
Ontario will have jurisdiction to entertain any action arising under this
Agreement. Each of the parties hereby attorns to the jurisdiction of the courts
of the Province of Ontario.

10.11    EXECUTION AND COUNTERPARTS

This Agreement may be executed by the Parties in counterparts and may be
executed and delivered by facsimile and all such counterparts and facsimiles
shall together constitute one and the same agreement.

[REMAINDER OF PAGE LEFT INTENTIONALLY BLANK]

<PAGE>

                                     - 48 -

IN WITNESS OF WHICH the Parties have executed this Agreement.

                                   GREENLIGHT POWER TECHNOLOGIES, INC.

                                   By: _________________________________________
                                       Name:  James Dean
                                       Title: President

                                   HYDROGENICS CORPORATION

                                   By: _________________________________________
                                       Name:  Jonathan Lundy
                                       Title: Vice-President, Corporate Affairs
                                              and Corporate Secretary

                                   VENTURES WEST 7 LIMITED PARTNERSHIP
                                   BY ITS GENERAL PARTNER VENTURES WEST 7
                                   MANAGEMENT LTD.

                                   By: _________________________________________
                                       Name: David Berkowitz

                                   By: _________________________________________
                                       Name:  Howard Riback
                                       Title: Vice-President

                                   VENTURES WEST 7 U.S. LIMITED
                                   PARTNERSHIP BY ITS MANAGER VENTURES WEST 7
                                   MANAGEMENT (INTERNATIONAL) INC.

                                   By: _________________________________________
                                       Name:  David Berkowitz

                                   By: _________________________________________
                                       Name:  Howard Riback
                                       Title: Vice-President

<PAGE>

                                     - 49 -

                                   HORTON TRADING LTD.

                                   By:__________________________________________
                                       Name:  Warwick Reid
                                       Title: President

SIGNED, SEALED & DELIVERED
In the presence of:

___________________________________     ________________________________________
             Witness                                ROGER HARPER

SIGNED, SEALED & DELIVERED
In the presence of:

___________________________________     ________________________________________
             Witness                              JACEK PIOTROWSKI

SIGNED, SEALED & DELIVERED
In the presence of:

___________________________________     ________________________________________
             Witness                                 GARRY SEDUN

SIGNED, SEALED & DELIVERED
In the presence of:

___________________________________     ________________________________________
             Witness                                DAVID CHAPMAN

SIGNED, SEALED & DELIVERED
In the presence of:

___________________________________     ________________________________________
             Witness                                 JAMES DEAN

                                        SEDUN FAMILY TRUST

                                        By: ____________________________________
                                             Garry Sedun
                                        By: ____________________________________
                                             Lynette Sedun

<PAGE>

                                     - 50 -

                                        PIOTROWSKI FAMILY TRUST

                                        By: ____________________________________
                                             Jacek Piotrowski
                                        By: ____________________________________
                                             Maria Piotrowski


<PAGE>

                                   SCHEDULE A

                    LIST OF MAJOR VENDORS AND SECURITIES HELD

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------

       Vendor                  Purchased Securities *          Purchase Price       Proportionate Share
-------------------------------------------------------------------------------------------------------------
<S>                           <C>                              <C>                  <C>
David Chapman                 642,646 Shares                   $ 2,542,364.89              8.2780%
                              350,000 Options
                              Chapman Option
-------------------------------------------------------------------------------------------------------------
James Dean                    642,646 Shares                   $ 2,542,364.89              8.2780%
                              350,000 Options
                              Dean Option
-------------------------------------------------------------------------------------------------------------
Roger Harper                  2,242,392 Shares                 $ 5,003,840.66             16.2901%
-------------------------------------------------------------------------------------------------------------
Jacek Piotrowski              1,203,497 Shares                 $ 2,685,571.08              8.7429%
-------------------------------------------------------------------------------------------------------------
Garry Sedun                   1,203,497 Shares                 $ 2,685,571.08              8.7429%
-------------------------------------------------------------------------------------------------------------
Piotrowski Family Trust       1,038,895 Shares                 $ 2,318,268.38              7.5472%
-------------------------------------------------------------------------------------------------------------
Sedun Family Trust            1,038,895 Shares                 $ 2,318,268.38              7.5472%
-------------------------------------------------------------------------------------------------------------
Horton Trading Ltd.           1,400,300 Shares                 $ 1,770,104.28              5.7626%
-------------------------------------------------------------------------------------------------------------
Ventures West 7 Limited       3,193,446 Shares                 $ 8,074,810.71             26.2877%
Partnership                   798,361 Series 1 Warrants
                              798,361 Series 2 Warrants
-------------------------------------------------------------------------------------------------------------
Ventures West                 306,554 Shares                   $   775,137.24              2.5235%
7 U.S. Limited Partnership    76,639 Series 1 Warrants
                              76,639 Series 2 Warrants
-------------------------------------------------------------------------------------------------------------
Total                         12,912,768 Shares                $30,716,301.59                 100%
                              700,000 Options
                              875,000 Series 1 Warrants
                              875,000 Series 2 Warrants
-------------------------------------------------------------------------------------------------------------
</TABLE>

*        "Shares" means common shares in the capital of the Company;

         "Options" means options granted pursuant to the employee stock option
         plan of the Company;

         "Series 1 Warrants" means warrants, expiring April 4, 2005, exercisable
         for common shares of the Company at an exercise price of $2.00 per
         share; and

         "Series 2 Warrants" means warrants, expiring April 4, 2005, exercisable
         for common shares of the Company at an exercise price of $4.00 per
         share.

<PAGE>

                                   SCHEDULE A1
            SECURITIES PURCHASED FOR CASH, ESCROWED SHARES AND SHARES

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------
                            PURCHASED                            ESCROWED          HYDROGENICS
         VENDOR             SECURITIES             CASH           SHARES              SHARES
--------------------------------------------------------------------------------------------------
<S>                      <C>                  <C>               <C>              <C>
David Chapman            162,804 Options      $  200,488.47          Nil               Nil

--------------------------------------------------------------------------------------------------
James Dean               162,804 Options      $  200,488.47          Nil               Nil

--------------------------------------------------------------------------------------------------
Roger Harper             2,199,900 Shares     $  538,875.22     158,024 Shares   496,190 Shares

--------------------------------------------------------------------------------------------------
Jacek Piotrowski         1,161,005 Shares     $  289,214.60     84,812 Shares    259,730 Shares

--------------------------------------------------------------------------------------------------
The Piotrowski Family    1,038,895 shares     $  249,659.42     73,212 Shares    236,460 Shares
Trust
--------------------------------------------------------------------------------------------------
Garry Sedun              1,161,005 Shares     $  289,214.60     84,812 Shares    259,730 Shares

--------------------------------------------------------------------------------------------------
The Sedun Family Trust   1,038,895 Shares     $  249,659.42     73,212 Shares    236,460 Shares
--------------------------------------------------------------------------------------------------
Horton Trading Ltd.      300,300 Shares       $   72,169.42     55,900 Shares    33,612 Shares

--------------------------------------------------------------------------------------------------
Ventures West 7 Limited  3,193,446 Shares     $  869,595.71     255,006 Shares   823,619 Shares
Partnership
                         798,361 Series 1
                             Warrants

                         798,361 Series 2
                             Warrants
--------------------------------------------------------------------------------------------------
Ventures West 7 U.S.     306,554 Shares       $   83,476.68     24,479 Shares    79,063 Shares
Limited Partnership
                         76,639 Series 1
                             Warrants

                         76,639 Series 2
                             Warrants
--------------------------------------------------------------------------------------------------
TOTAL                    325,608 OPTIONS      $3,042,842.01     809,457 SHARES   2,424,864 SHARES

                         10,400,000 SHARES

                         875,000 SERIES 1
                             WARRANTS

                         875,000 SERIES 2
                             WARRANTS
--------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                                   SCHEDULE A2
          SECURITIES PURCHASED FOR WARRANTS, ESCROWED SHARES AND SHARES

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------
                             PURCHASED                                  ESCROWED         HYDROGENICS
        VENDOR              SECURITIES             WARRANTS              SHARES             SHARES
---------------------------------------------------------------------------------------------------------
<S>                      <C>                 <C>                     <C>                <C>
David Chapman            187,196 Options     Warrant exercisable           Nil               Nil
                                              for 34,509 Shares

---------------------------------------------------------------------------------------------------------
David Chapman            642,646 Shares              Nil             80,302 Shares      134,376 Shares

---------------------------------------------------------------------------------------------------------
James Dean               187,196 Options     Warrant exercisable           Nil               Nil
                                              for 34,509 Shares

---------------------------------------------------------------------------------------------------------
James Dean               642,646 Shares              Nil             80,302 Shares      134,376 Shares

---------------------------------------------------------------------------------------------------------
Roger Harper             42,492 Shares               Nil                   Nil          14,194 Shares

---------------------------------------------------------------------------------------------------------
Jacek Piotrowski         42,492 Shares               Nil                   Nil          14,194 Shares

---------------------------------------------------------------------------------------------------------
Garry Sedun              42,492 Shares               Nil                   Nil          14,194 Shares

---------------------------------------------------------------------------------------------------------
TOTAL                    1,412,768 SHARES    WARRANTS EXERCISABLE    160,604 SHARES     311,334 SHARES
                                              FOR 69,018 SHARES
                         374,392 OPTIONS
---------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                                   SCHEDULE A3
            SECURITIES PURCHASED FOR CASH, ESCROWED SHARES AND SHARES

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------
                              PURCHASED                                ESCROWED          HYDROGENICS
    VENDOR                    SECURITIES              CASH              SHARES              SHARES
---------------------------------------------------------------------------------------------------------
<S>                        <C>                     <C>                 <C>              <C>
David Chapman              Horton Contract         $ 72,940.94            Nil           90,474 Shares

---------------------------------------------------------------------------------------------------------
James Dean                 Horton Contract         $ 72,940.94            Nil           90,474 Shares

---------------------------------------------------------------------------------------------------------
TOTAL                      HORTON CONTRACTS        $145,881.88            NIL           180,948 SHARES
---------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                                   SCHEDULE A4
            SECURITIES PURCHASED FOR CASH, ESCROWED SHARES AND SHARES

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------
                              PURCHASED                                ESCROWED          HYDROGENICS
       VENDOR                 SECURITIES               CASH             SHARES              SHARES
---------------------------------------------------------------------------------------------------------
<S>                        <C>                     <C>                 <C>              <C>
Horton Trading Ltd.        1,100,000 Shares        $118,462.22            Nil           146,936 Shares
                            purchased under
                            Horton Contract
---------------------------------------------------------------------------------------------------------
TOTAL                      1,100,000 SHARES        $118,462.22            NIL           146,936 SHARES
---------------------------------------------------------------------------------------------------------
</TABLE>