<SEC-DOCUMENT>0001104659-21-136342.txt : 20211109
<SEC-HEADER>0001104659-21-136342.hdr.sgml : 20211109
<ACCEPTANCE-DATETIME>20211109170230
ACCESSION NUMBER:		0001104659-21-136342
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210922
FILED AS OF DATE:		20211109
DATE AS OF CHANGE:		20211109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Shrestha Sanjay K
		CENTRAL INDEX KEY:			0001775802

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34392
		FILM NUMBER:		211393100

	MAIL ADDRESS:	
		STREET 1:		968 ALBANY SHAKER RD
		CITY:			LATHAM
		STATE:			NY
		ZIP:			12110

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PLUG POWER INC
		CENTRAL INDEX KEY:			0001093691
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRICAL INDUSTRIAL APPARATUS [3620]
		IRS NUMBER:				223672377
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		968 ALBANY-SHAKER ROAD
		CITY:			LATHAM
		STATE:			NY
		ZIP:			12110
		BUSINESS PHONE:		5187827700

	MAIL ADDRESS:	
		STREET 1:		968 ALBANY-SHAKER ROAD
		CITY:			LATHAM
		STATE:			NY
		ZIP:			12110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>tm2131018-5_4seq1.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-09-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001093691</issuerCik>
        <issuerName>PLUG POWER INC</issuerName>
        <issuerTradingSymbol>PLUG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001775802</rptOwnerCik>
            <rptOwnerName>Shrestha Sanjay K</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PLUG POWER INC.</rptOwnerStreet1>
            <rptOwnerStreet2>968 ALBANY SHAKER ROAD</rptOwnerStreet2>
            <rptOwnerCity>LATHAM</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>12110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Strategy Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Stock Option (Right to Buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26.92</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-09-22</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2000000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-09-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Awarded pursuant to Plug Power's 2021 Stock Option and Incentive Plan.</footnote>
        <footnote id="F2">Up to one-third (1/3) of the shares underlying the performance stock options will vest and become exercisable on each of the first three anniversaries of the grant date, provided that the daily volume weighted average price of the Company's common stock during any 30 consecutive trading day period in the three year performance period following the grant date of the stock options (&quot;VWAP&quot;) equals or exceeds certain levels. 25% of the shares underlying the performance stock options will be deemed to have satisfied the performance-based vesting and will be eligible to vest over time if the VWAP equals $35; an additional 25% of the shares underlying the options will be deemed to have satisfied the performance-based vesting and will be eligible to vest over time if the VWAP equals $50; and the remaining 50% of the shares underlying the options will be deemed to have satisfied the performance-based vesting and will be eligible to vest over time if the VWAP equals or exceeds $100.</footnote>
        <footnote id="F3">If the VWAP falls between two of the stock price hurdles, an incremental number of shares underlying the options will become exercisable based on linear interpolation in $1 increments. Failure to achieve any of the stock price hurdles applicable to a performance stock option during the three-year performance period will result in applicable options being un-exercisable. The performance-based stock options have a maximum term of seven years from the grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Gerard L. Conway, Jr., Attorney-in-Fact</signatureName>
        <signatureDate>2021-11-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
