PLUG POWER INC

​

APPENDIX A​

SIXTH CERTIFICATE OF AMENDMENT

OF

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

OF

PLUG POWER INC

(Pursuant to Section 242

of the General Corporation Law of the State of Delaware)

Plug Power Inc., a corporation organized and existing under the General Corporation Law of the State of Delaware (the “Corporation”), hereby certifies as follows:

FIRST: Upon the effectiveness of this Sixth Amendment (the “Sixth Amendment”) to the Amended and Restated Certificate of Incorporation of the Corporation (the “Certificate of Incorporation”), the first paragraph of Article IV of the Certificate of Incorporation is hereby deleted and replaced in its entirety with the following:

“The total number of shares of capital stock which the Corporation shall have the authority to issue is Three Billion Five Million (3,005,000,000) shares, of which (i) Three Billion (3,000,000,000) shares shall be common stock, par value $0.01 per share (the “Common Stock”), and (ii) Five Million (5,000,000) shares shall be preferred stock, par value $0.01 per share (the “Undesignated Preferred Stock).”

SECOND: Upon the effectiveness of this Sixth Amendment, the fifth paragraph of Article IV of the Certificate of Incorporation is hereby deleted and replaced in its entirety with the following:

“Except as otherwise provided in any certificate of designation of any series of Undesignated Preferred Stock, and notwithstanding anything to the contrary in Article IX of this Amended and Restated Certificate of Incorporation or otherwise, the number of authorized shares of the class of Common Stock or Undesignated Preferred Stock may be increased or decreased (but not below the number of shares of such class then outstanding) by the requisite vote of the holders of the capital stock of the Corporation entitled to vote thereon as provided in Section 242(d)(2) of the DGCL, and no vote of the holders of either the Common Stock or Undesignated Preferred Stock voting separately as a class shall be required therefor irrespective of the provisions of Section 242(b)(2) of the DGCL.”

THIRD: The foregoing amendments were duly adopted in accordance with the provisions of Section 242 of the General Corporation Law of the State of Delaware.

IN WITNESS WHEREOF, the Corporation has caused this Sixth Certificate of Amendment of Amended and Restated Certificate of Incorporation to be executed by Andrew Marsh, its Chief Executive Officer, this day of , 2026.

Name:

Title:

PLUG POWER INC.C/O BROADRIDGE CORPORATE ISSUER SOLUTIONSP.O. BOX 1342BRENTWOOD, NY 11717VOTE BY INTERNETBefore The Meeting - Go to www.proxyvote.com or scan the QR Barcode aboveUse the Internet to transmit your voting instructions and for electronic delivery of information.Vote by 11:59 P.M. ET on January 28, 2026. Have your notice or proxy card in hand when youaccess the website, which will contain your voter control number, and follow the instructionsto obtain your records.During The Meeting - Go to www.virtualshareholdermeeting.com/PLUG2026SMYou may attend the meeting via the Internet and vote during the meeting. Have the informationthat is printed in the box marked by the arrow available and follow the instructions.VOTE BY PHONE -1-800-690-6903 Use any touch-tone telephone to transmit your voting instructions. Vote by 11:59 P.M. ETon January 28, 2026. Have your notice or proxy card in hand when you call and then followthe instructions.VOTE BY MAILMark, sign and date your proxy card and return it in the postage-paid envelope we haveprovided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood,NY 11717. Your proxy card must be received by 11:59 P.M. ET on January 28, 2026.TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS:V81479-S25957KEEP THIS PORTION FOR YOUR RECORDSTHIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. DETACH AND RETURN THIS PORTION ONLYThe Board of Directors recommends you vote "FOR" proposals 1, 2 and 3.For Against AbstainThe Board of Directors recommends you vote "FOR" proposals 1, 2 and 3.1. The approval of an amendment to the Company's charter to adjust the voting requirements for certain future amendments to the charter to align withSection 242(d)(2) of the Delaware General Corporation Law.2. The approval of an amendment to the Company's charter to increase the number of authorized shares of the Company's common stock from1,500,000,000 to 3,000,000,000 shares.3. The approval of the adjournment of the Special Meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies if there areinsufficient votes for the approval of Proposal 1 or Proposal 2.Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Jointowners should each sign personally. All holders must sign. If a corporation or partnership, please sign in full corporate or partnership name by authorized officer.Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date

Important Notice Regarding the Availability of Proxy Materials for the Special Meeting:The Notice and Proxy Statement is available at www.proxyvote.com.V81480-S25957Special Meeting of the Stockholders ofPLUG POWER INC.January 29, 2026 at 10:00 AM Eastern TimeSOLICITED ON BEHALF OF THE BOARD OF DIRECTORSThe stockholder(s) hereby acknowledges receipt of the Notice of Special Meeting of Stockholders and Proxy Statement, andhereby appoint(s) each of Andrew J. Marsh and Gerard L. Conway, Jr., as proxies, each with the power to appoint his substitute,and authorize(s) them to represent and to vote all of the shares of common stock of PLUG POWER INC. that the stockholder(s)is/are entitled to vote at the Special Meeting of Stockholders to be held at 10:00 AM, Eastern Time, on January 29, 2026, overthe Internet at www.virtualshareholdermeeting.com/PLUG2026SM, and at any adjournment or postponement thereof, upon thematters set forth in the Notice of Special Meeting of Stockholders and Proxy Statement dated December 12 , 2025.THIS PROXY, WHEN PROPERLY EXECUTED, WILL BE VOTED IN THE MANNER DIRECTED BY THE UNDERSIGNEDSTOCKHOLDER. IF PROPERLY EXECUTED AND NO DIRECTION IS MADE, THIS PROXY WILL BE VOTED "FOR" THE APPROVALOF AN AMENDMENT TO THE COMPANY’S CHARTER TO ADJUST THE VOTING REQUIREMENTS FOR CERTAIN FUTUREAMENDMENTS TO THE CHARTER TO ALIGN WITH SECTION 242(D)(2) OF THE DELAWARE GENERAL CORPORATION LAWIN PROPOSAL 1, "FOR" THE APPROVAL OF AN AMENDMENT TO THE COMPANY’S CHARTER TO INCREASE THE NUMBEROF AUTHORIZED SHARES OF THE COMPANY’S COMMON STOCK FROM 1,500,000,000 TO 3,000,000,000 SHARES INPROPOSAL 2, AND "FOR" THE APPROVAL OF THE ADJOURNMENT OF THE SPECIAL MEETING TO A LATER DATE ORDATES, IF NECESSARY OR APPROPRIATE, TO SOLICIT ADDITIONAL PROXIES IF THERE ARE INSUFFICIENT VOTES FORTHE APPROVAL OF PROPOSAL 1 OR PROPOSAL 2 IN PROPOSAL 3. THIS PROXY WILL BE VOTED IN THE DISCRETIONOF THE PROXIES ON ANY OTHER MATTERS THAT MAY PROPERLY COME BEFORE THE MEETING.