Exhibit 10.1

EMPLOYMENT AGREEMENT

This Employment Agreement (“Agreement”) is made as of the 7th day of April, 2008, between Plug Power Inc., a Delaware corporation (the “Company”), and Andrew Marsh (the “Executive”).

WHEREAS, the Executive and the Company desire to enter into this Agreement setting forth the terms and conditions for the employment relationship of the Executive with the Company.

NOW, THEREFORE, in consideration of the mutual covenants and agreements herein contained and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties agree as follows:

1. Employment . The term of this Agreement shall extend from April 8, 2008 (the “Commencement Date”) until the first anniversary of the Commencement Date; provided, however, that the term of this Agreement shall automatically be extended for one additional year on the anniversary of the Commencement Date and on each anniversary thereafter unless, not less than 90 days prior to each such date, either party shall have given notice to the other that it does not wish to extend this Agreement; provided, further, that if a Change in Control occurs during the original or extended term of this Agreement, the term of this Agreement shall continue in effect for a period of not less than 12 months beyond the month in which the Change in Control occurred. The term of this Agreement shall also terminate upon any Date of Termination (as defined in Section 4) and may be referred to herein as the “Term.”

2. Position and Duties . During the Term, the Executive shall serve as the Chief Executive Officer and President of the Company, and shall have supervision and control over and responsibility for the day-to-day business and affairs of the Company and shall have such other powers and duties as may from time to time be prescribed by the Chairman of the Board of Directors of the Company (the “Board”), provided that such duties are consistent with the Executive’s position or other positions that he may hold from time to time. The Executive shall devote his full working time and efforts to the business and affairs of the Company. Notwithstanding the foregoing, the Executive may serve on other boards of directors, with the approval of the Board, or engage in religious, charitable or other community activities as long as such services and activities are disclosed to the Board and do not materially interfere with the Executive’s performance of his duties to the Company as provided in this Agreement.

3. Compensation and Related Matters .

(a) Base Salary . The Executive’s initial annual base salary shall be $375,000.00. The Executive’s base salary shall be redetermined annually by the Compensation Committee of the Board. The base salary in effect at any given time is referred to herein as “Base Salary.” The Base Salary shall be payable in substantially equal bi-weekly installments.

(b) Bonuses . The Executive shall be eligible to earn an annual cash bonus pursuant to the terms of the Plug Power Executive Incentive Plan (the “Bonus Plan”) as in effect from time to time. For fiscal year 2008, the Executive will be eligible to earn an annual cash

bonus under the Bonus Plan of up to 50% of his Base Salary. Within sixty days of the Commencement Date, the Executive and the Company shall agree on the metrics to be used in measuring the Executive’s performance and the resulting bonus.

(c) Incentive Equity . The Executive will be eligible to participate in the Company’s 1999 Stock Option and Incentive Plan (the “Plan”). On the Commencement Date, the Company will grant to the Executive under the Plan a non-qualified stock option to purchase up to 400,000 shares of the Company’s common stock. The option will vest in three installments of 133,333 1/3 shares each on the first, second and third anniversaries of the date of grant. The exercise price of the option will be equal to the closing price of the Company’s common stock on the NASDAQ Global Market on the date of grant. The option will be subject to the terms of the Plan and the Company’s standard form Non-Qualified Stock Option Agreement for employees.

(d) Relocation . The Company will reimburse the Executive for the following reasonable and documented expenses incurred by the Executive in connection with relocating his home from Texas to the Albany, New York area: movement and storage of household goods; real estate brokerage costs relating to the sale of the Executive’s home in Texas; travel, food and lodging expenses for a house-hunting trip to the Albany area; closing costs relating to the purchase of a new home; and temporary living expenses for housing in the Albany area for up to three months. The Company will also provide the Executive with a tax gross-up on such reimbursed amounts.

(e) Expenses . The Executive shall be entitled to receive prompt reimbursement for all reasonable expenses incurred by him in performing services hereunder during the Term, in accordance with the policies and procedures then in effect and established by the Company for its senior executive officers.

(f) Other Benefits . During the Term, the Executive shall be entitled to continue to participate in or receive benefits under all of the Company’s Employee Benefit Plans in effect on the date hereof, or under plans or arrangements that provide the Executive with benefits at least substantially equivalent to those provided under such Employee Benefit Plans. As used herein, the term “Employee Benefit Plans” includes, without limitation, each pension and retirement plan; supplemental pension, retirement and deferred compensation plan; savings and profit-sharing plan; stock ownership plan; stock purchase plan; stock option plan; life insurance plan; medical insurance plan; disability plan; and health and accident plan or arrangement established and maintained by the Company on the date hereof for employees of the same status within the hierarchy of the Company. During the Term, the Executive shall be entitled to participate in or receive benefits under any employee benefit plan or arrangement which may, in the future, be made available by the Company to its executives and key management employees, subject to and on a basis consistent with the terms, conditions and overall administration of such plan or arrangement. Any payments or benefits payable to the Executive under a plan or arrangement referred to in this Section 3(f) in respect of any calendar year during which the Executive is employed by the Company for less than the whole of such year shall, unless otherwise provided in the applicable plan or arrangement, be prorated in accordance with the number of days in such calendar year during which he is so employed. Should any such payments or benefits accrue on a fiscal (rather than calendar) year, then the proration in the preceding sentence shall be on the basis of a fiscal year rather than calendar year.

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(g) Vacations . The Executive shall be entitled to twenty (20) paid vacation days in each calendar year, which shall be accrued ratably during the calendar year. The Executive shall also be entitled to all paid holidays given by the Company to its executives.

4. Termination . The Executive’s employment hereunder may be terminated without any breach of this Agreement under the following circumstances:

(a) Death . The Executive’s employment hereunder shall terminate upon his death.

(b) Disability . The Company may terminate the Executive’s employment if he is disabled and unable to perform the essential functions of the Executive’s then existing position or positions under this Agreement with or without reasonable accommodation for a period of 180 days (which need not be consecutive) in any 12-month period. If any question shall arise as to whether during any period the Executive is disabled so as to be unable to perform the essential functions of the Executive’s then existing position or positions with or without reasonable accommodation, the Executive may, and at the request of the Company shall, submit to the Company a certification in reasonable detail by a physician selected by the Company to whom the Executive or the Executive’s guardian has no reasonable objection as to whether the Executive is so disabled or how long such disability is expected to continue, and such certification shall for the purposes of this Agreement be conclusive of the issue. The Executive shall cooperate with any reasonable request of the physician in connection with such certification. If such question shall arise and the Executive shall fail to submit such certification, the Company’s determination of such issue shall be binding on the Executive. Nothing in this Section 4(b) shall be construed to waive the Executive’s rights, if any, under existing law including, without limitation, the Family and Medical Leave Act of 1993, 29 U.S.C. §2601 et seq . and the Americans with Disabilities Act, 42 U.S.C. §12101 et seq.

(c) Termination by Company for Cause . At any time during the Term, the Company may terminate the Executive’s employment hereunder for Cause. For purposes of this Agreement, “Cause” shall mean: (i) a willful act of dishonesty by the Executive with respect to any matter involving the Company or any subsidiary or affiliate, or (ii) conviction of the Executive of a crime involving moral turpitude, or (iii) the gross or willful failure by the Executive to substantially perform the Executive’s duties with the Company (other than any such failure after the Executive gives notice of termination for “Good Reason”), which failure is not cured within 30 days after a written demand for substantial performance is received by the Executive from the Board which specifically identifies the manner in which the Board believes the Executive has not substantially performed the Executive’s duties. For purposes of clauses (i) and (iii) hereof, no act, or failure to act, on the Executive’s part shall be deemed “willful” unless done, or omitted to be done, by the Executive without reasonable belief that the Executive’s act, or failure to act, was in the best interests of the Company and its subsidiaries and affiliates.

(d) Termination Without Cause . At any time during the Term, the Company may terminate the Executive’s employment hereunder without Cause. Any termination by the Company of the Executive’s employment under this Agreement which does not constitute a termination for Cause under Section 4(c) or result from the death or disability of the Executive under Section 4(a) or (b) shall be deemed a termination without Cause.

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(e) Termination by the Executive . At any time during the Term, the Executive may terminate his employment hereunder for any reason, including but not limited to Good Reason from and after a Change in Control (as defined in Section 6(c)). If the Executive provides notice to the Company under Section 1 that he elects to discontinue the extensions, such action shall be deemed a voluntary termination by the Executive and one without Good Reason. For purposes of this Agreement, “Good Reason” shall mean that the Executive has complied with the “Good Reason Process” (hereinafter defined) following the occurrence of any of the following events after a Change in Control: (i) a material diminution in the Executive’s responsibilities, authority or duties; (ii) a material diminution in the Executive’s Base Salary; (iii) a material change in the geographic location at which the Executive provides services to the Company; or (iv) the material breach of this Agreement by the Company. “Good Reason Process” shall mean that (i) the Executive reasonably determines in good faith that a “Good Reason” condition has occurred; (ii) the Executive notifies the Company in writing of the occurrence of the Good Reason condition within 60 days of the occurrence of such condition; (iii) the Executive cooperates in good faith with the Company’s efforts, for a period not less than 30 days following such notice (the “Cure Period”), to remedy the condition; (iv) notwithstanding such efforts, the Good Reason condition continues to exist; and (v) the Executive terminates his employment within 60 days after the end of the Cure Period. If the Company cures the Good Reason condition during the Cure Period, Good Reason shall be deemed not to have occurred.

(f) Notice of Termination . Except for termination as specified in Section 4(a), any termination of the Executive’s employment by the Company or any such termination by the Executive shall be communicated by written Notice of Termination to the other party hereto. For purposes of this Agreement, a “Notice of Termination” shall mean a notice which shall indicate the specific termination provision in this Agreement relied upon.

(g) Date of Termination . “Date of Termination” shall mean: (i) if the Executive’s employment is terminated by his death, the date of his death; (ii) if the Executive’s employment is terminated by the Company for Cause under Section 4(c), the date on which Notice of Termination is given; (iii) if the Executive’s employment is terminated by the Company under Section 4(b) or 4(d), 30 days after the date on which a Notice of Termination is given; (iv) if the Executive’s employment is terminated by the Executive under Section 4(e) without Good Reason, 30 days after the date on which a Notice of Termination is given, and (v) if the Executive’s employment is terminated by the Executive under Section 4(e) with Good Reason, the date on which a Notice of Termination is given after the end of the Cure Period. Notwithstanding the foregoing, in the event that the Executive gives a Notice of Termination to the Company, the Company may unilaterally accelerate the Date of Termination and such acceleration shall not result in a termination by the Company for purposes of this Agreement.

5. Compensation Upon Termination .

(a) Termination Generally . If the Executive’s employment with the Company is terminated for any reason during the Term, within 30 days of the Date of Termination, the Company shall pay or provide to the Executive (or to his authorized representative or estate) any earned but unpaid base salary, incentive compensation earned but not yet paid, unpaid expense reimbursements, accrued but unused vacation and any vested benefits the Executive may have under any employee benefit plan of the Company through the Date of Termination (the “Accrued Benefit”). The Executive shall not be entitled to receive any other termination payments or benefits from the Company except as specifically provided in Section 5(b) or Section 6.

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(b) Termination by the Company Without Cause . If the Executive’s employment is terminated by the Company without Cause as provided in Section 4(d), then the Company shall, through the Date of Termination, pay the Executive his Accrued Benefit. If (i) the Executive’s employment is terminated by the Company without Cause as provided in Section 4(d), (ii) the Executive signs a general release of claims in a form and manner satisfactory to the Company (the “Release”) within 21 days of the receipt of the Release and does not revoke such Release during the seven-day revocation period, and (iii) the Executive complies with the Employee Patent, Confidential Information and Non-Compete Agreement dated April 7, 2008 between the Executive and the Company (the “Confidentiality Agreement”), then:

(A) the Company shall pay the Executive an amount equal to the sum of (A) 1.0 times the Executive’s Base Salary plus (B) 1.0 times the Executive’s annual bonus for the immediately preceding fiscal year. Such amount shall be paid out in a lump sum on the first payroll date after the Date of Termination or expiration of the seven-day revocation period for the Release, if later;

(B) upon the Date of Termination, all stock options and other stock-based awards held by the Executive in which the Executive would have vested if he had remained employed for an additional 12 months following the Date of Termination shall vest and become exercisable or nonforfeitable as of the Date of Termination;

(C) subject to the Executive’s copayment of premium amounts at the active employees’ rate, the Executive may continue to participate in the Company’s then applicable group health, dental, vision and life insurance program for 12 months following the Date of Termination , and the Company shall provide continuation of health benefits after this 12-month period pursuant to the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended (“COBRA”), such benefits to be determined as though the Executive’s employment had terminated at the end of such 12-month period; and

(D) the Company shall pay to the Executive not later than 60 days after the receipt of invoices from the Executive, all reasonable legal and arbitration fees and expenses incurred by the Executive in obtaining or enforcing any right or benefit provided by this Agreement, except in the cases involving frivolous or bad faith claims.

6. Change in Control Payment . The provisions of this Section 6 set forth certain terms regarding the Executive’s rights and obligations upon the occurrence of a Change in Control of the Company. These provisions are intended to assure and encourage in advance the Executive’s continued attention and dedication to his assigned duties and his objectivity during the pendency and after the occurrence of any such event. These provisions shall apply in lieu of, and expressly supersede, the provisions of Section 5(b) regarding severance pay and benefits

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upon a termination of employment, if such termination of employment occurs within 12 months after the occurrence of the first event constituting a Change in Control, provided that such first event occurs during the Term. These provisions shall terminate and be of no further force or effect beginning 12 months after the occurrence of a Change in Control.

(a) Change in Control . If (i) within 12 months after a Change in Control, the Executive’s employment is terminated by the Company without Cause as provided in Section 4(d) or the Executive terminates his employment for Good Reason as provided in Section 4(e), (ii) the Executive signs the Release within 21 days of the receipt of the Release and does not revoke the Release during the seven-day revocation period, and (iii) the Executive complies with the Confidentiality Agreement, then

(A) the Company shall pay the Executive a lump sum in cash in an amount equal to the product of (A) 3.0, multiplied by (B) the sum of (1) the Executive’s current Base Salary, plus (2) the Executive’s Average Incentive Compensation (or the Executive’s annual bonus for the fiscal year immediately preceding the Change in Control, if higher). Such amount shall be paid on the first payroll date following the Date of Termination or the expiration of the seven-day revocation period for the Release, if later. For purposes of this Agreement, “Average Incentive Compensation” shall mean the average of the annual cash bonus compensation under Section 3(b) received by the Executive for the three immediately preceding fiscal years. In no event shall “Average Incentive Compensation” include any sign-on bonus, retention bonus or any other special bonus;

(B) upon the Date of Termination, all stock options and other stock-based awards held by the Executive in which the Executive would have vested if he had remained employed for an additional 12 months following the Date of Termination shall vest and become exercisable or nonforfeitable as of the Date of Termination;

(C) subject to the Executive’s copayment of premium amounts at the active employees’ rate, the Executive may continue to participate in the Company’s group health, dental, vision and life insurance program for 12 months following the Date of Termination, and the Company shall provide continuation of health benefits after this 12-month period pursuant to COBRA, such benefits to be determined as though the Executive’s employment had terminated at the end of such 12-month period; and

(D) the Company shall pay to the Executive not later than 60 days after the receipt of invoices from the Executive, all reasonable legal and arbitration fees and expenses incurred by the Executive in obtaining or enforcing any right or benefit provided by this Agreement, except in the cases involving frivolous or bad faith claims.

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(b) Additional Limitation .

(i) Anything in this Agreement to the contrary notwithstanding, in the event that any compensation, payment or distribution by the Company to or for the benefit of the Executive, whether paid or payable or distributed or distributable pursuant to the terms of this Agreement or otherwise (the “Severance Payments”), would be subject to the excise tax imposed by Section 4999 of the Code, the following provisions shall apply:

(A) If the Severance Payments, reduced by the sum of (1) the Excise Tax and (2) the total of the Federal, state, and local income and employment taxes payable by the Executive on the amount of the Severance Payments which are in excess of the Threshold Amount, are greater than or equal to the Threshold Amount, the Executive shall be entitled to the full benefits payable under this Agreement.

(B) If the Threshold Amount is less than (x) the Severance Payments, but greater than (y) the Severance Payments reduced by the sum of (1) the Excise Tax and (2) the total of the Federal, state, and local income and employment taxes on the amount of the Severance Payments which are in excess of the Threshold Amount, then the benefits payable under this Agreement shall be reduced (but not below zero) to the extent necessary so that the maximum Severance Payments shall not exceed the Threshold Amount.

(ii) For the purposes of this Section 6(b), “Threshold Amount” shall mean three times the Executive’s “base amount” within the meaning of Section 280G(b)(3) of the Code and the regulations promulgated thereunder less one dollar ($1.00); and “Excise Tax” shall mean the excise tax imposed by Section 4999 of the Code, and any interest or penalties incurred by the Executive with respect to such excise tax.

(iii) The determination as to which of the alternative provisions of Section 6(b)(i) shall apply to the Executive shall be made by a nationally recognized accounting firm selected by the Company (the “Accounting Firm”), which shall provide detailed supporting calculations both to the Company and the Executive within 15 business days of the Date of Termination, if applicable, or at such earlier time as is reasonably requested by the Company or the Executive. For purposes of determining which of the alternative provisions of Section 6(b)(i) shall apply, the Executive shall be deemed to pay federal income taxes at the highest marginal rate of federal income taxation applicable to individuals for the calendar year in which the determination is to be made, and state and local income taxes at the highest marginal rates of individual taxation in the state and locality of the Executive’s residence on the Date of Termination, net of the maximum reduction in federal income taxes which could be obtained from deduction of such state and local taxes. Any determination by the Accounting Firm shall be binding upon the Company and the Executive.

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(c) Definitions . For purposes of this Section 6, the following terms shall have the following meanings:

“Change in Control” shall be deemed to have occurred in any one of the following events:

(i) any “person,” as such term is used in Sections 13(d) and 14(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), (other than the Company, any of its subsidiaries, any trustee, fiduciary or other person or entity holding securities under any employee benefit plan or trust of the Company or any of its subsidiaries, or, Smart Hydrogen Inc., a BVI Business Company (“Smart Hydrogen”), and any Permitted Transferee (as defined in the Company’s Certificate of Designations of Class B Capital Stock filed with the Delaware Secretary of State and as may be amended from time to time (the “Class B Certificate of Designations”)), together with all Affiliates and Associates (as such terms are hereinafter defined) of such person, shall become the “beneficial owner” (as such term is defined in Rule 13d-3 of the Exchange Act), directly or indirectly, of securities of the Company representing 25 percent or more of the then outstanding shares of common stock of the Company (the “Stock”) (other than as a result of an acquisition of securities directly from the Company); or

(ii) persons who, as of the effective date of this Agreement (the “Effective Date”), constitute the Company’s Board of Directors (the “Incumbent Directors”) cease for any reason, including, without limitation, as a result of a tender offer, proxy contest, merger or similar transaction, to constitute at least a majority of the Board, provided that any person becoming a director of the Company subsequent to the Effective Date shall be considered an Incumbent Director if such person’s election was approved by or such person was nominated for election by either (i) a vote of at least a majority of the Incumbent Directors, (ii) a vote of at least a majority of the Incumbent Directors who are members of a nominating committee comprised, in the majority, of Incumbent Directors, or (iii) in the case of a Class B director, the holders of the Company’s Class B Capital Stock in accordance with the Class B Certificate of Designations; but provided further, that any such person whose initial assumption of office is in connection with an actual or threatened election contest relating to the election of members of the Board of Directors or other actual or threatened solicitation of proxies or consents by or on behalf of a Person other than the Board, including by reason of agreement intended to avoid or settle any such actual or threatened contest or solicitation, shall not be considered an Incumbent Director; or

(iii) Upon (A) the consummation of any consolidation or merger of the Company where the shareholders of the Company, immediately prior to the consolidation or merger, did not, immediately after the consolidation or merger, beneficially own (as such term is defined in Rule 13d-3 of the Exchange Act), directly or indirectly, shares representing in the aggregate more than 50 percent of the voting shares of the corporation issuing cash or securities in the consolidation or merger (or of its ultimate parent corporation, if any), (B) the consummation of any sale, lease, exchange or other transfer (in one transaction or a series of transactions contemplated or arranged by any party as a single plan) of all or substantially all of the assets of the Company or (C) the completion of a liquidation or dissolution that has been approved by the stockholders of the Company; or

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(iv) Smart Hydrogen or any Permitted Transferee (as defined in the Class B Certificate of Designations), together with all Affiliates and Associates (as such terms are hereinafter defined) of such person, shall become the “beneficial owner” (as such term is defined in Rule 13d-3 of the Exchange Act), directly or indirectly, of securities of the Company representing 50 percent or more of the then outstanding Stock (other than as a result of an acquisition of securities directly from the Company).

Notwithstanding the foregoing, a “Change in Control” shall not be deemed to have occurred for purposes of the foregoing clauses (i) or (iv) solely as the result of an acquisition of securities by the Company which, by reducing the number of shares of Stock outstanding, increases the proportionate number of shares of Stock beneficially owned by any person to 25 percent or more (or 50 percent or more in the case of clause (iv)) of the shares of Stock then outstanding; provided, however, that if any such person shall at any time following such acquisition of securities by the Company become the beneficial owner of any additional shares of Stock (other than pursuant to a stock split, stock dividend, or similar transaction) and such person immediately thereafter is the beneficial owner of 25 percent or more (or 50 percent or more in the case of clause (iv)) of the shares of Stock then outstanding, then a “Change in Control” shall be deemed to have occurred for purposes of the foregoing clause (i) or (iv), as applicable.

7. Section 409A .

(a) Anything in this Agreement to the contrary notwithstanding, if at the time of the Executive’s “separation from service” within the meaning of Section 409A of the Code, the Company determines that the Executive is a “specified employee” within the meaning of Section 409A(a)(2)(B)(i) of the Code, and to the extent any payment or benefit that the Executive becomes entitled to under this Agreement would be considered deferred compensation subject to the 20 percent additional tax imposed pursuant to Section 409A(a) of the Code as a result of the application of Section 409A(a)(2)(B)(i) of the Code, then no such payment shall be payable and no such benefit shall be provided prior to the date that is the earlier of (A) six months and one day after the Executive’s separation from service, or (B) the Executive’s death.

(b) The parties intend that this Agreement will be administered in accordance with Section 409A of the Code. To the extent that any provision of this Agreement is ambiguous as to its compliance with Section 409A of the Code, the provision shall be read in such a manner so that all payments hereunder comply with Section 409A of the Code. The parties agree that this Agreement may be amended, as reasonably requested by either party, and as may be necessary to fully comply with Section 409A of the Code and all related rules and regulations in order to preserve the payments and benefits provided hereunder without additional cost to either party.

(c) The Company makes no representation or warranty and shall have no liability to the Executive or any other person if any provisions of this Agreement are determined to constitute deferred compensation subject to Section 409A of the Code but do not satisfy an exemption from, or the conditions of, such Section.

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8. Covenants .

(a) Litigation and Regulatory Cooperation . During and after the Term, the Executive shall cooperate fully with the Company and all of its subsidiaries and affiliates (including its and their outside counsel) in connection with the contemplation, prosecution and defense of all phases of existing, past and future claims or actions which relate to events or occurrences that transpired while the Executive was employed by the Company. The Executive’s full cooperation in connection with such claims or actions shall include, but not be limited to, being available to meet with counsel to prepare for discovery or trial and to act as a witness on behalf of the Company at mutually convenient times. During and after the Term, the Executive also shall cooperate fully with the Company in connection with any investigation or review of any federal, state or local regulatory authority as any such investigation or review relates to events or occurrences that transpired while the Executive was employed by the Company. The Company shall reimburse the Executive for any pre-approved reasonable business travel expenses that are incurred in connection with the Executive’s performance of obligations pursuant to this Section 8(a) after receipt of appropriate documentation consistent with the Company’s business expense reimbursement policy.

(b) Disparagement . During and after the Term, the Executive agrees not to make any disparaging statements concerning the Company or any of its subsidiaries, affiliates or current or former officers, directors, shareholders, employees or agents (“Company Parties”). The Executive further agrees not to take any actions or conduct himself in any way that would reasonably be expected to affect adversely the reputation or good will of the Company or any of the Company Parties. The Executive further agrees that he shall not voluntarily provide information to or otherwise cooperate with any individual or entity that is contemplating or pursuing litigation against any of the Company Parties or that is undertaking any investigation or review of any of the Company Parties’ activities or practices; provided, however, that the Executive may participate in or otherwise assist in any investigation or inquiry conducted by the EEOC or the New York Division of Human Rights. These nondisparagement obligations shall not in any way affect the Executive’s obligation to testify truthfully in any legal proceeding.

(c) Employee Patent, Confidential Information and Non-Compete Agreement . In consideration for the Company’s undertakings under this Agreement, the Executive will execute and abide by the terms of the Confidentiality Agreement, which is appended hereto and the terms of which are incorporated by reference. The Executive acknowledges that the terms of the Confidentiality Agreement are reasonable and necessary to safeguard confidential information and to protect the Company’s goodwill with its customers and that the terms of the Confidentiality Agreement are reasonable in duration and geographic scope, given the worldwide nature of the Company’s business.

(d) Return of Property . As soon as possible in connection with any termination of the Executive’s employment under this Agreement, the Executive shall return to the Company all Company property, including, without limitation, computer equipment, software, keys and access cards, credit cards, files and any documents (including computerized

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data and any copies made of computer data or software) containing information concerning the Company, its business or its business relationships (in the latter two cases, actual or prospective). The Executive shall also commit to deleting and finally purging any duplicates of files or documents that may contain Company information from any computer or other device that remains his property after any Date of Termination.

(e) Injunction . The Executive agrees that it would be difficult to measure any damages caused to the Company which might result from any breach by the Executive of his obligations under this Section 8, and that in any event money damages would be an inadequate remedy for any such breach. Accordingly, subject to Section 9 of this Agreement, the Executive agrees that if the Executive breaches, or proposes to breach, any provision of this Agreement, the Company shall be entitled, in addition to all other remedies that it may have, to an injunction or other appropriate equitable relief to restrain any such breach without showing or proving any actual damage to the Company.

9. Settlement and Arbitration of Disputes . Any controversy or claim arising out of or relating to this Agreement or the breach thereof shall be settled exclusively by arbitration in accordance with the laws of the State of New York by three arbitrators, one of whom shall be appointed by the Company, one by the Executive and the third by the first two arbitrators. If the first two arbitrators cannot agree on the appointment of a third arbitrator, then the third arbitrator shall be appointed by the American Arbitration Association in the City of Albany. Such arbitration shall be conducted in the City of Albany in accordance with the Employment Dispute Resolutions Rules of the American Arbitration Association, except with respect to the selection of arbitrators which shall be as provided in this Section 9. Judgment upon the award rendered by the arbitrators may be entered in any court having jurisdiction thereof. This Section 9 shall be specifically enforceable. Notwithstanding the foregoing, this Section 9 shall not preclude either party from pursuing a court action for the sole purpose of obtaining a temporary restraining order or a preliminary injunction in circumstances in which such relief is appropriate; provided that any other relief shall be pursued through an arbitration proceeding pursuant to this Section 9.

10. Consent to Jurisdiction . To the extent that any court action is permitted consistent with or to enforce Section 9 of this Agreement, the parties hereby consent to the jurisdiction of the Supreme Courts of New York State and the United States District Court for the Northern District of New York. Accordingly, with respect to any such court action, the Executive (a) submits to the personal jurisdiction of such courts; (b) consents to service of process; and (c) waives any other requirement (whether imposed by statute, rule of court, or otherwise) with respect to personal jurisdiction or service of process.

11. Integration . This Agreement, together with the Confidentiality Agreement, constitutes the entire agreement and understanding between the parties with respect to the subject matter hereof and supersedes all prior agreements between the parties concerning such subject matter.

12. Withholding . All payments made by the Company to the Executive under this Agreement shall be net of any tax or other amounts required to be withheld by the Company under applicable law.

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13. Successor to the Executive . This Agreement shall inure to the benefit of and be enforceable by the Executive’s personal representatives, executors, administrators, heirs, distributees, devisees and legatees. In the event of the Executive’s death after his termination of employment but prior to the completion by the Company of all payments due him under this Agreement, the Company shall continue such payments to the Executive’s beneficiary designated in writing to the Company prior to his death (or to his estate, if the Executive fails to make such designation).

14. Enforceability . If any portion or provision of this Agreement (including, without limitation, any portion or provision of any section of this Agreement) shall to any extent be declared illegal or unenforceable by a court of competent jurisdiction, then the remainder of this Agreement, or the application of such portion or provision in circumstances other than those as to which it is so declared illegal or unenforceable, shall not be affected thereby, and each portion and provision of this Agreement shall be valid and enforceable to the fullest extent permitted by law.

15. Waiver . No waiver of any provision hereof shall be effective unless made in writing and signed by the waiving party. The failure of any party to require the performance of any term or obligation of this Agreement, or the waiver by any party of any breach of this Agreement, shall not prevent any subsequent enforcement of such term or obligation or be deemed a waiver of any subsequent breach.

16. Notices . Any notices, requests, demands and other communications provided for by this Agreement shall be sufficient if in writing and delivered in person or sent by a nationally recognized overnight courier service or by registered or certified mail, postage prepaid, return receipt requested, to the Executive at the last address the Executive has filed in writing with the Company or, in the case of the Company, at its main offices, attention of the Board.

17. Effect on Other Plans . Nothing in this Agreement shall be construed to limit the rights of the Executive under the Company’s benefit plans, programs or policies except (a) as otherwise provided herein, and (b) that the Executive shall have no rights to any severance or similar benefits under any severance pay plan, policy or practice.

18. Amendment . This Agreement may be amended or modified only by a written instrument signed by the Executive and by a duly authorized representative of the Company.

19. Governing Law . This is a New York contract and shall be construed under and be governed in all respects by the laws of the State of New York, without giving effect to the conflict of laws principles of such State. With respect to any disputes concerning federal law, such disputes shall be determined in accordance with the law as it would be interpreted and applied by the United States Court of Appeals for the Second Circuit.

20. Expenses . The Company will pay all reasonable and documented legal fees and expenses incurred by the Executive in connection with the negotiation of this Agreement, up to a maximum of $5,000.00.

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21. Counterparts . This Agreement may be executed in any number of counterparts, each of which when so executed and delivered shall be taken to be an original; but such counterparts shall together constitute one and the same document.

22. Successor to Company . The Company shall require any successor (whether direct or indirect, by purchase, merger, consolidation or otherwise) to all or substantially all of the business or assets of the Company expressly to assume and agree to perform this Agreement to the same extent that the Company would be required to perform it if no succession had taken place. Failure of the Company to obtain an assumption of this Agreement at or prior to the effectiveness of any succession shall be a breach of this Agreement and shall constitute Good Reason if the Executive elects to terminate employment.

23. Gender Neutral . Wherever used herein, a pronoun in the masculine gender shall be considered as including the feminine gender unless the context clearly indicates otherwise.

IN WITNESS WHEREOF, the parties have executed this Agreement effective on the date and year first above written.

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Exhibit 10.2

NON-QUALIFIED STOCK OPTION AGREEMENT

FOR COMPANY EMPLOYEES

UNDER THE

PLUG POWER INC.

1999 STOCK OPTION AND INCENTIVE PLAN

Pursuant to the Plug Power Inc. 1999 Stock Option and Incentive Plan as amended through the date hereof (the “Plan”), Plug Power Inc. (the “Company”) hereby grants to the Optionee named above, who is an officer or employee of the Company or any of its Subsidiaries, an option (the “Stock Option”) to purchase on or prior to the Expiration Date specified above all or part of the number of shares (the “Option Shares”) of Common Stock, par value $.01 per share (the “Stock”) of the Company specified above at the Option Exercise Price per Share specified above, subject to the terms and conditions set forth herein and in the Plan. This Stock Option is not intended to be an “incentive stock option” under Section 422 of the Internal Revenue Code of 1986, as amended.

1. Vesting Schedule . No portion of this Stock Option may be exercised until such portion shall have vested. Except as set forth below, and subject to the discretion of the Administrator (as defined in Section 2 of the Plan) to accelerate the vesting schedule hereunder, this Stock Option shall be vested and exercisable with respect to the following number of Option Shares on the dates indicated:

In the event of a Covered Transaction as defined in Section 3(c) of the Plan or a Change of Control as defined in Section 17 of the Plan, this Stock Option shall become vested and exercisable in full as of the effective date of such Covered Transaction or Change of Control, respectively, whether or not this Stock Option or any portion thereof is vested and exercisable at such time, and may be exercised in accordance with the provisions hereof and of the Plan.

2. Manner of Exercise .

(a) The Optionee may exercise this Stock Option only in the following manner: from time to time on or prior to the Expiration Date of this Stock Option, the Optionee may give written notice to the Administrator of his or her election to purchase some or all of the vested Option Shares purchasable at the time of such notice. This notice shall specify the number of Option Shares to be purchased.

Payment of the purchase price for the Option Shares may be made by one or more of the following methods: (i) in cash, by certified or bank check or other instrument acceptable to the Administrator; (ii) by the Optionee delivering (or attesting to the ownership of) shares of Stock (A) that have been purchased on the open market or (B) that have been held by the Optionee for at least six months (or such shorter or longer period as may be determined by the Administrator) and are not then subject to restrictions under any Company plan; (iii) by the Optionee delivering to the Company a properly executed exercise notice together with irrevocable instructions to a broker to promptly deliver to the Company cash or a check payable and acceptable to the Company to pay the option purchase price, provided that in the event the Optionee chooses to pay the option purchase price as so provided, the Optionee and the broker shall comply with such procedures and enter into such agreements of indemnity and other agreements as the Administrator shall prescribe as a condition of such payment procedure; or (iv) a combination of (i), (ii) and (iii) above. Payment instruments will be received subject to collection.

The delivery of certificates representing (or transfer to the Optionee on the records of the Company or its transfer agent of) the Option Shares will be contingent upon the Company’s receipt from the Optionee of full payment for the Option Shares, as set forth above and any agreement, statement or other evidence that the Company may require to satisfy itself that the issuance of Stock to be purchased pursuant to the exercise of Stock Options under the Plan and any subsequent resale of the shares of Stock will be in compliance with applicable laws and regulations. In the event the Optionee chooses to pay the purchase price by previously owned shares of Stock through the attestation method, the number of shares of Stock delivered or transferred to the Optionee upon the exercise of the Stock Option shall be net of the Shares attested to.

(b) Certificates for the shares of Stock purchased upon exercise of this Stock Option shall be issued and delivered (or, if such shares are uncertificated, such shares shall be transferred on the records of the Company or its transfer agent) to the Optionee upon compliance to the satisfaction of the Administrator with all requirements under applicable laws or regulations in connection with such issuance and with the requirements hereof and of the Plan. The determination of the Administrator as to such compliance shall be final and binding on the Optionee. The Optionee shall not be deemed to be the holder of, or to have any of the rights of a holder with respect to, any shares of Stock subject to this Stock Option unless and until this Stock Option shall have been exercised pursuant to the terms hereof, the Company shall have issued and delivered or transferred the shares to the Optionee, and the Optionee’s name shall have been entered as the stockholder of record on the books of the Company. Thereupon, the Optionee shall have full voting, dividend and other ownership rights with respect to such shares of Stock.

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(c) The minimum number of shares with respect to which this Stock Option may be exercised at any one time shall be 100 shares, unless the number of shares with respect to which this Stock Option is being exercised is the total number of shares subject to exercise under this Stock Option at the time.

(d) Notwithstanding any other provision hereof or of the Plan, no portion of this Stock Option shall be exercisable after the Expiration Date hereof.

3. Termination of Employment . If the Optionee’s employment by the Company or a Subsidiary (as defined in the Plan) is terminated, the period within which to exercise this Stock Option may be subject to earlier termination as set forth below.

(a) Termination Due to Death . If the Optionee’s employment terminates by reason of the Optionee’s death, this Stock Option shall become fully exercisable and may thereafter only be exercised by the Optionee’s legal representative or legatee for a period of 12 months from the date of death or until the Expiration Date, if earlier.

(b) Termination Due to Disability . If the Optionee’s employment terminates by reason of the Optionee’s Disability (within the meaning of Section 22(e)(3) of the Code), this Stock Option shall become fully exercisable and may thereafter only be exercised by the Optionee for a period of 12 months from the date of termination or until the Expiration Date, if earlier. The death of the Optionee during the 12-month period provided in this Section 3(b) shall extend such period for another 12 months from the date of death or until the Expiration Date, if earlier.

(c) Termination for Cause . If the Optionee’s employment terminates for Cause (as defined in the Plan), this Stock Option shall terminate immediately and be of no further force and effect.

(d) Other Termination . If the Optionee’s employment terminates for any reason other than death, Disability or Cause, and unless otherwise determined by the Administrator, this Stock Option may only be exercised by the Optionee, to the extent exercisable on the date of termination, for a period of 12 months from the date of termination or until the Expiration Date, if earlier. Any portion of this Stock Option that is not exercisable at such time shall terminate immediately and be of no further force and effect.

(e) Miscellaneous . The Administrator’s determination of the reason for termination of the Optionee’s employment shall be conclusive and binding on the Optionee and his or her representatives or legatees. Any portion of this Stock Option that is not exercisable after the application of this Section 3 shall be canceled immediately upon any termination of employment and shall not be exercisable by the Optionee.

4. Incorporation of Plan . Notwithstanding anything herein to the contrary, this Stock Option shall be subject to and governed by all the terms and conditions of the Plan, including the powers of the Administrator set forth in Section 2(b) of the Plan. Capitalized terms in this Agreement shall have the meaning specified in the Plan, unless a different meaning is specified herein.

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5. Transferability . This Agreement is personal to the Optionee, is non-assignable and is not transferable in any manner, by operation of law or otherwise, other than by will or the laws of descent and distribution. This Stock Option is exercisable, during the Optionee’s lifetime, only by the Optionee, and thereafter, only by the Optionee’s legal representative or legatee.

6. Tax Withholding . The Optionee shall, not later than the date as of which the exercise of this Stock Option becomes a taxable event for Federal income tax purposes, pay to the Company or make arrangements satisfactory to the Administrator for payment of any Federal, state, and local taxes required by law to be withheld on account of such taxable event.

7. Effect of Employment Agreement . If the Optionee is a party to an employment agreement with the Company and any provisions set forth in such employment agreement conflict with the provisions set forth in this Stock Option Agreement, the provisions set forth in such employment agreement shall override such conflicting provisions set forth herein.

8. Miscellaneous .

(a) Notice hereunder shall be given to the Company at its principal place of business, and shall be given to the Optionee at the address set forth below, or in either case at such other address as one party may subsequently furnish to the other party in writing.

(b) This Stock Option does not confer upon the Optionee any rights with respect to continuance of employment by the Company or any Subsidiary.

(c) Pursuant to Section 15 of the Plan, the Administrator may at any time amend or cancel any outstanding portion of this Stock Option, but no such action may be taken which adversely affects the Optionee’s rights under this Agreement without the Optionee’s consent.

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The foregoing Agreement is hereby accepted and the terms and conditions thereof hereby agreed to by the undersigned.

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