EMPLOYMENT AGREEMENT

Exhibit 10.21

EMPLOYMENT AGREEMENT

This Employment Agreement (“Agreement”) is made and entered into as of October 2, 2013 (the “Effective Date”), by and between Pattern Energy Group Inc., a Delaware corporation (hereafter the “Company”), and Daniel M. Elkort (“Executive”).

1. Employment. During the Employment Period (as defined in Section 4 below), the Company shall employ Executive, and Executive shall serve, as Executive Vice President and General Counsel of the Company.

2. Duties and Responsibilities of Executive.

3. Compensation. Any salary, bonus and other compensation payments hereunder shall be subject to all applicable payroll and other taxes, deductions and withholdings.

4. Term of Employment. The initial term of this Agreement shall be for the period beginning on the Effective Date and ending at midnight Eastern Time on the first anniversary of the Effective Date (the “Initial Term”). On the first anniversary of the Effective Date and on each subsequent anniversary of the Effective Date, this Agreement shall automatically renew and extend for a period of 12 months (each such 12-month period being a “Renewal Term”) unless written notice of non-renewal is delivered from either party to the other not less than sixty (60) days prior to the expiration of the then-existing Initial Term or Renewal Term. Notwithstanding any other provision of this Agreement, the Executive’s employment pursuant to this Agreement may be terminated at any time in accordance with Section 6. The period from the Effective Date through the expiration of this Agreement or, if sooner, the termination of Executive’s employment pursuant to this Agreement, regardless of the time or reason for such termination, shall be referred to herein as the “Employment Period.”

5. Benefits. Subject to the terms and conditions of this Agreement, Executive shall be entitled to the following benefits during the Employment Period:

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6. Termination of Employment.

Upon thirty (30) days advance written notice, the Company shall have the right to terminate Executive’s employment for convenience.

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Notwithstanding the foregoing provisions of this Section 6(c) or any other provision of this Agreement to the contrary, any assertion of Executive of a termination for Good Reason shall not be effective unless all of the following conditions are satisfied: (A) Executive must provide written notice to the Company of the condition described in Sections 6(c)(i), 6(c)(ii), 6(c)(iii) or 6(c)(iv) that gives rise to Executive’s belief that Good Reason for termination exists within sixty (60) days after Executive first becomes aware of the initial existence of the condition; (B) the condition specified in such notice must remain uncorrected for thirty (30) days after receipt of such notice by the Company; and (C) the date of Executive’s termination of employment must occur within ninety-one (91) days after Executive first becomes aware of the initial existence of the condition specified in such notice.

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7. Conflicts of Interest. Executive agrees that he shall promptly disclose to the Board any conflict of interest involving Executive upon Executive becoming aware of such conflict.

8. Confidentiality. Executive acknowledges and agrees that, in the course of his employment with the Company, he will be provided with, and have access to, valuable Confidential Information (as defined below) of the Company, its Affiliates and of third parties who have supplied such information to the Company or its Affiliates, as applicable. In consideration of Executive’s receipt and access to such Confidential Information and in exchange for other valuable consideration provided hereunder, Executive agrees to comply with this Section 8.

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9. Ownership of Intellectual Property. Executive agrees that the Company shall own, and Executive agrees to assign and does hereby assign, all right, title and interest (including but not limited to patent rights, copyrights, trade secret rights, mask work rights, trademark rights, and all other intellectual and industrial property rights of any sort throughout the world) relating to any and all inventions (whether or not patentable), works of authorship, mask works, designs, know-how, ideas and information authored, created, contributed to, made or conceived or reduced to practice, in whole or in part, by Executive during the Employment Period which (a) relate, at the time of conception, reduction to practice, creation, derivation or development, to the Company’s or any of its Affiliates’ business or research or development, and (b) were developed on any amount of the Company’s time or with the use of any of the Company’s or its Affiliates’ equipment, supplies, facilities, trade secret information or other Confidential Information (all of the foregoing collectively referred to herein as “Company Intellectual Property”), and Executive will promptly disclose all Company Intellectual Property to the Company. All of Executive’s works of authorship and associated copyrights created during the Employment Period and in the scope of Executive’s employment shall be deemed to be “works made for hire” within the meaning of the Copyright Act of 1976, as amended. Executive agrees to perform, during and after the Employment Period, all reasonable acts deemed necessary by the Company to assist the Company, at the Company’s expense, in obtaining and enforcing its rights throughout the world in the Company Intellectual Property. Such acts may include, but are not limited to, execution of documents and reasonable assistance or cooperation (i) in the filing, prosecution, registration, and memorialization of assignment of any applicable patents, copyrights, mask work, or other applications, (ii) in the enforcement of any applicable patents, copyrights, mask work, moral rights, trade secrets, or other proprietary rights, and (iii) in other legal proceedings related to the Company Intellectual Property.

10. Defense of Claims. Executive agrees that, during the Employment Period and thereafter, upon reasonable request from the Company, Executive will reasonably cooperate with

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the Company or its Affiliates in the defense of any claims or actions that may be made by or against the Company or its Affiliates that relate to Executive’s actual or prior areas of responsibility, except if Executive’s reasonable interests are adverse to the Company or its Affiliate(s), as applicable, in such claim or action. The Company agrees to pay or reimburse Executive for all of Executive’s reasonable travel and other direct expenses incurred, or to be reasonably incurred, to comply with Executive’s obligations under this Section 10, provided that Executive provides reasonable documentation of same no later than thirty (30) days after incurring such expenses. Reimbursement of expenses under this Section 10 shall be made no later than thirty (30) days after Executive submits all supporting documentation. Executive is not permitted to receive a payment or benefit in lieu of or in exchange for reimbursement under this Section 10. The amount of expenses eligible for reimbursement in one year will not affect the amount of expenses eligible for reimbursement in any other year.

11. Arbitration

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12. Withholdings; Right of Offset. The Company may withhold and deduct from any payments made or to be made pursuant to this Agreement (a) all federal, state, local and other taxes as may be required pursuant to any law or governmental regulation or ruling or (b) any deductions consented to in writing by Executive.

13. Title and Headings; Construction. Titles and headings to Sections hereof are for the purpose of reference only and shall in no way limit, define or otherwise affect the provisions hereof. Any and all exhibits or attachments referred to in this Agreement are, by such reference, incorporated herein and made a part hereof for all purposes. The words “herein,” “hereof,” “hereunder” and other compounds of the word “here” shall refer to the entire Agreement and not to any particular provision hereof.

14. Applicable Law; Submission to Jurisdiction. This Agreement shall in all respects be governed and construed according to the laws of the State of California. With respect to any

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claim or dispute related to or arising under this Agreement, the parties hereby consent to the arbitration provisions of Section 11 above and recognize and agree that should any resort to a court be necessary and permitted under this Agreement, then they consent to the exclusive jurisdiction, forum and venue of the state and federal courts located in San Francisco, California.

15. Entire Agreement and Amendment. This Agreement contains the entire agreement of the parties with respect to the matters covered herein; moreover, this Agreement supersedes all prior and contemporaneous agreements and understandings, oral or written, between the parties hereto concerning the subject matter hereof. This Agreement may be amended only by a written instrument executed by both parties hereto.

16. Waiver of Breach. Any waiver of this Agreement must be executed by the party to be bound by such waiver. No waiver by either party hereto of a breach of any provision of this Agreement by the other party, or of compliance with any condition or provision of this Agreement to be performed by such other party, will operate or be construed as a waiver of any subsequent breach by such other party or any similar or dissimilar provision or condition at the same or any subsequent time. The failure of either party hereto to take any action by reason of any breach will not deprive such party of the right to take action at any time while such breach continues.

17. Assignment. This Agreement is personal to Executive, and neither this Agreement nor any rights or obligations hereunder shall be assignable or otherwise transferred by Executive. The Company may assign this Agreement to any of its Affiliates and to any successor (whether by merger, purchase or otherwise) to all or substantially all of the equity, assets or businesses of the Company, if such successor expressly agrees to assume the obligations of the Company hereunder.

18. Affiliates. For purposes of this Agreement, the term “Affiliates” is defined as any person or entity Controlling, Controlled by, under common Control with the Company, or managed by the same executives as those who manage the day to day operations of the Company. The term “Control,” including the correlative term “Controlled By” means possession, directly or indirectly, of the power to direct or cause the direction of management or policies (whether through ownership of securities or any Company or other ownership interest, by contract or otherwise) of a person or entity. For the purposes of the preceding sentence, Control shall be deemed to exist when a person or entity possesses, directly or indirectly, through one or more intermediaries (a) in the case of a corporation more than 50% of the outstanding voting securities thereof; (b) in the case of a limited liability company, partnership, limited partnership or venture, the right to more than 50% of the distributions therefrom (including liquidating distributions); or (c) in the case of any other person or entity, more than 50% of the economic or beneficial interest therein.

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19. Notices. Notices provided for in this Agreement shall be in writing and shall be deemed to have been duly received (a) when delivered in person or sent by facsimile transmission, (b) on the first business day after such notice is sent by air express overnight courier service, or (c) on the third business day following deposit in the United States mail, registered or certified mail, return receipt requested, postage prepaid and addressed, to the following address, as applicable:

Pattern Energy Group Inc.

Attn: General Counsel

Pier 1, Bay 3

San Francisco, CA 94111

Facsimile: (415)  ###-###-####

Daniel M. Elkort

100 Ivy Drive

P.O. Box 1836

Ross, CA 94957

20. Counterparts. This Agreement may be executed in any number of counterparts, including by facsimile or e-mail pdf, each of which when so executed and delivered shall be an original, but all such counterparts shall together constitute one and the same instrument. Each counterpart may consist of a copy hereof containing multiple signature pages, each signed by one party, but together signed by both parties hereto.

21. Deemed Resignations. Unless otherwise agreed to in writing by the Company and Executive prior to the termination of Executive’s employment, any termination of Executive’s employment shall constitute: (i) an automatic resignation of Executive as an officer of the Company and each Affiliate of the Company, as applicable, and (ii) an automatic resignation of Executive from the Board (if applicable), from the board of directors of any Affiliate of the Company (if applicable), and from the board of directors or any similar governing body of any corporation, limited liability entity or other entity in which the Company or any Affiliate holds an equity interest and with respect to which board or similar governing body Executive serves as the Company’s or such Affiliate’s designee or other representative (if applicable).

22. Compliance with Code Section 409A. The intent of the parties is that the payments and benefits under this Agreement comply with or be exempt from Section 409A of the Internal Revenue Code of 1986, as amended, and the regulations and guidance promulgated thereunder (collectively, “Section 409A”) and, accordingly, to the maximum extent permitted, this Agreement shall be interpreted to be in compliance therewith. To the extent that any reimbursements under this Agreement are subject to Section 409A, any such reimbursements payable to Executive shall be paid to Executive no later than December 31 of the year following the year in which the expense was incurred; provided, that Executive submits Executive’s reimbursement request promptly following the date the expense is incurred, the amount of expenses reimbursed in one year shall not affect the amount eligible for reimbursement in any subsequent year, other than medical expenses referred to in Section 105(b) of the Code, and Executive’s right to reimbursement under this Agreement will not be subject to liquidation or exchange for another benefit. Except as otherwise permitted under Section 409A, no payment hereunder shall be accelerated or deferred unless such acceleration or deferral would not result in additional tax or interest pursuant to Section 409A

23. Separate Payments. Each payment under this Agreement shall be treated as a right to a separate payment for purposes of Section 409A of the Code.

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IN WITNESS WHEREOF, Executive and the Company each have caused this Agreement to be executed in its name and on its behalf, to be effective as of the Effective Date.

SIGNATURE PAGE TO EMPLOYMENT AGREEMENT

EXHIBIT A

RELEASE AGREEMENT

This Release Agreement (this “Agreement”) constitutes the release referred to in that certain Employment Agreement (the “Employment Agreement”) dated as of October 2, 2013, by and between Daniel M. Elkort (“Executive”) and Pattern Energy Group Inc. (the “Company”).

(a) For good and valuable consideration, including the Company’s provision of a severance payment to Executive in accordance with Section 6(f)(i) of the Employment Agreement, Executive hereby releases, discharges and forever acquits the Company, its Affiliates (as defined in the Employment Agreement) and subsidiaries, the past, present and future stockholders, members, partners, directors, managers, employees, agents, attorneys, heirs, representatives, successors and assigns of the foregoing, in their personal and representative capacities (collectively, the “Company Parties”) from liability for, and hereby waives, any and all claims, damages, or causes of action of any kind related to Executive’s employment with any Company Party, the termination of such employment, and any other acts or omissions related to any matter on or prior to the date of the execution of this Agreement including without limitation any alleged violation through the date of this Agreement of: (i) the Age Discrimination in Employment Act of 1967, as amended; (ii) Title VII of the Civil Rights Act of 1964, as amended; (iii) the Civil Rights Act of 1991; (iv) Section 1981 through 1988 of Title 42 of the United States Code, as amended; (v) Employee Retirement Income Security Act of 1974, as amended; (vi) the Immigration Reform Control Act, as amended; (vii) the Americans with Disabilities Act of 1990, as amended; (viii) the National Labor Relations Act, as amended; (ix) the Occupational Safety and Health Act, as amended; (x) the Family and Medical Leave Act of 1993; (xi) any state anti-discrimination law; (xii) any state wage and hour law; (xiii) any other local, state or federal law, regulation or ordinance; (xiv) any public policy, contract, tort, or common law claim; (xv) any allegation for costs, fees, or other expenses including attorneys’ fees incurred in these matters; (xvi) any and all rights, benefits or claims Executive may have under any employment contract, incentive compensation plan or equity plan with any Company Party or to any ownership interest in any Company Party except as expressly provided in the Employment Agreement and any equity or other equity compensation agreement between Executive and the Company and (xvii) any claim for compensation or benefits of any kind not expressly set forth in the Employment Agreement or any equity compensation agreement (collectively, the “Released Claims”). In no event shall the Released Claims include (a) any claim which arises after the date of this Agreement, (b) any claims for payments under the Employment Agreement, if such payments are payable after the date of this Agreement, (c) any claim of Executive to vested benefits under an employee benefit plan, (d) any rights or health benefits of Executive under Consolidated Omnibus Budget Reconciliation Act of 1985 or (e) any rights under the Limited Company Agreement of Pattern Energy Holdings LP. This Agreement is not intended to indicate that any such claims exist or that, if they do exist, they are meritorious. Rather, Executive is simply agreeing that, in exchange for the consideration recited in the first sentence of this paragraph, any and all potential claims of this nature that Executive may have against the Company Parties, regardless of whether they actually exist, are

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expressly settled, compromised and waived. By signing this Agreement, Executive is bound by this Agreement. Anyone who succeeds to rights and responsibilities, including but not limited to successors by merger, heirs or the executor of Executive’s estate, is bound by this Agreement. This release also applies to any claims brought by any person or agency or class action under which the Executive may have a right or benefit. Notwithstanding the release of liability contained herein, nothing in this Agreement prevents Executive from filing any non-legally waivable claim (including a challenge to the validity of this Agreement) with the Equal Employment Opportunity Commission (“EEOC”) or comparable state or local agency or participating in any investigation or proceeding conducted by the EEOC or comparable state or local agency; however, Executive understands and agrees that Executive is waiving any and all rights to recover any monetary or personal relief or recovery as a result of such EEOC or comparable state or local agency proceeding or subsequent legal actions. THIS RELEASE INCLUDES MATTERS ATTRIBUTABLE TO THE SOLE OR PARTIAL NEGLIGENCE (WHETHER GROSS OR SIMPLE) OR OTHER FAULT, INCLUDING STRICT LIABILITY, OF ANY OF THE COMPANY PARTIES.

(b) Executive agrees not to bring or join any lawsuit against any of the Company Parties in any court relating to any of the Released Claims. Executive represents that Executive has not brought or joined any lawsuit or filed any charge or claim against any of the Company Parties in any court or before any government agency and has made no assignment of any rights Executive has asserted or may have against any of the Company Parties to any person or entity, in each case, with respect to any Released Claims.

(c) By executing and delivering this Agreement, Executive acknowledges that:

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(d) Executive acknowledges and agrees that he is aware of California Civil Code Section 1542, which provides as follows;

A general release does not extend to claims which the creditor does not know or suspect to exist in his favor at the time of executing the release, which if known by him must have materially affected his settlement with the debtor.

With full awareness and understanding of the above provisions, Executive hereby waives any and all right he may have under Section 1542, as well as under any other statutes or common law principles of similar effect. Executive intends to, and hereby does, release the Released Parties from claims which he does not presently know or suspect to exist.

(e) Notwithstanding the initial effectiveness of this Agreement, Executive may revoke the delivery (and therefore the effectiveness) of this Agreement within the seven-day period beginning on the date Executive delivers this Agreement to the Company (such seven day period being referred to herein as the “Release Revocation Period”). To be effective, such revocation must be in writing signed by Executive and must be delivered to the Chairman of the Board of Directors of Pattern Energy Group Inc. before 11:59 p.m., Eastern Time, on the last day of the Release Revocation Period. If an effective revocation is delivered in the foregoing manner and timeframe, this Agreement shall be of no force or effect and shall be null and void ab initio. No consideration shall be paid if this Agreement is revoked by Executive in the foregoing manner.

Executed on this             day of             ,             .

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SCHEDULE 1

None

SCHEDULE 1