-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 M3GmMCgOAxVZfrlm61dXReEGk6/cKEFISEZf20gQGplc6ZxTk3bUnwDHZeUO+2Aq
 NFnQ7ufpNOtbHgpqxocKoQ==

<SEC-DOCUMENT>0000064463-03-000048.txt : 20030512
<SEC-HEADER>0000064463-03-000048.hdr.sgml : 20030512
<ACCEPTANCE-DATETIME>20030512141032
ACCESSION NUMBER:		0000064463-03-000048
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030509
FILED AS OF DATE:		20030512

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MECHANICAL TECHNOLOGY INC
		CENTRAL INDEX KEY:			0000064463
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		IRS NUMBER:				141462255
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		431 NEW KARNER ROAD
		STREET 2:		BUILDING #4
		CITY:			ALBANY
		STATE:			NY
		ZIP:			12205
		BUSINESS PHONE:		5185332200

	MAIL ADDRESS:	
		STREET 1:		431 NEW KARNER ROAD
		STREET 2:		BUILDING #4
		CITY:			ALBANY
		STATE:			NY
		ZIP:			12205

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MECHANICAL TECHNOLOGY INC
		CENTRAL INDEX KEY:			0000064463
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06890
		FILM NUMBER:		03692397

	BUSINESS ADDRESS:	
		STREET 1:		431 NEW KARNER ROAD
		STREET 2:		BUILDING #4
		CITY:			ALBANY
		STATE:			NY
		ZIP:			12205
		BUSINESS PHONE:		5185332200

	MAIL ADDRESS:	
		STREET 1:		431 NEW KARNER ROAD
		STREET 2:		BUILDING #4
		CITY:			ALBANY
		STATE:			NY
		ZIP:			12205
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>mec52.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

<documentType>4</documentType>
	<periodOfReport>2003-05-09</periodOfReport>
	<notSubjectToSection16>0</notSubjectToSection16>
<issuer>		<issuerCik>0000064463</issuerCik>
        <issuerName>MECHANICAL TECHNOLOGY INC</issuerName>
<issuerTradingSymbol>PLUG</issuerTradingSymbol>
	</issuer>
	<reportingOwner>
		<reportingOwnerId>
			<rptOwnerCik>0000064463</rptOwnerCik>
            <rptOwnerName>MECHANICAL TECHNOLOGY INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
<reportingOwnerRelationship>
			<isDirector>0</isDirector>
			<isOfficer>0</isOfficer>
			<isTenPercentOwner>1</isTenPercentOwner>
			<isOther>0</isOther>
		</reportingOwnerRelationship>
	</reportingOwner>
	<nonDerivativeSecurity>
		<securityTitle>
			<value>Plug Power Inc. - Common Stock</value>
		</securityTitle>
		<transactionDate>
			<value>2003-05-05</value>
		</transactionDate>
		<transactionCoding>
			<transactionFormType>4</transactionFormType>
			<transactionCode>S</transactionCode>
			<equitySwapInvolved>0</equitySwapInvolved>
		</transactionCoding>
		<transactionAmounts>
			<transactionShares>
				<value>10000</value>
			</transactionShares>
			<transactionValue>
				<value>5.09</value>
			</transactionValue>
			<transactionAcquiredDisposedCode>
				<value>D</value>
			</transactionAcquiredDisposedCode>
		</transactionAmounts>
		<postTransactionAmounts>
			<sharesOwnedFollowingTransaction>
				<value>7410720.00</value>
			</sharesOwnedFollowingTransaction>
		</postTransactionAmounts>
		<ownershipNature>
			<directOrIndirectOwnership>
				<value>D</value>
			</directOrIndirectOwnership>
			<natureOfOwnership>
				<value/>
			</natureOfOwnership>
		</ownershipNature>
	</nonDerivativeSecurity>
	<nonDerivativeSecurity>
		<securityTitle>
			<value>Plug Power Inc. - Common Stock</value>
		</securityTitle>
		<transactionDate>
			<value>2003-05-06</value>
		</transactionDate>
		<transactionCoding>
			<transactionFormType>4</transactionFormType>
			<transactionCode>S</transactionCode>
			<equitySwapInvolved>0</equitySwapInvolved>
		</transactionCoding>
		<transactionAmounts>
			<transactionShares>
				<value>9500</value>
			</transactionShares>
			<transactionValue>
				<value>5.09</value>
			</transactionValue>
			<transactionAcquiredDisposedCode>
				<value>D</value>
			</transactionAcquiredDisposedCode>
		</transactionAmounts>
		<postTransactionAmounts>
			<sharesOwnedFollowingTransaction>
				<value>7401220.00</value>
			</sharesOwnedFollowingTransaction>
		</postTransactionAmounts>
		<ownershipNature>
			<directOrIndirectOwnership>
				<value>D</value>
			</directOrIndirectOwnership>
			<natureOfOwnership>
				<value/>
			</natureOfOwnership>
		</ownershipNature>
	</nonDerivativeSecurity>
	<nonDerivativeSecurity>
		<securityTitle>
			<value>Plug Power Inc. - Common Stock</value>
		</securityTitle>
		<transactionDate>
			<value>2003-05-07</value>
		</transactionDate>
		<transactionCoding>
			<transactionFormType>4</transactionFormType>
			<transactionCode>S</transactionCode>
			<equitySwapInvolved>0</equitySwapInvolved>
		</transactionCoding>
		<transactionAmounts>
			<transactionShares>
				<value>10000</value>
			</transactionShares>
			<transactionValue>
				<value>5.09</value>
			</transactionValue>
			<transactionAcquiredDisposedCode>
				<value>D</value>
			</transactionAcquiredDisposedCode>
		</transactionAmounts>
		<postTransactionAmounts>
			<sharesOwnedFollowingTransaction>
				<value>7391220.00</value>
			</sharesOwnedFollowingTransaction>
		</postTransactionAmounts>
		<ownershipNature>
			<directOrIndirectOwnership>
				<value>D</value>
			</directOrIndirectOwnership>
			<natureOfOwnership>
				<value/>
			</natureOfOwnership>
		</ownershipNature>
	</nonDerivativeSecurity>
	<nonDerivativeSecurity>
		<securityTitle>
			<value>Plug Power Inc. - Common Stock</value>
		</securityTitle>
		<transactionDate>
			<value>2003-05-08</value>
		</transactionDate>
		<transactionCoding>
			<transactionFormType>4</transactionFormType>
			<transactionCode>S</transactionCode>
			<equitySwapInvolved>0</equitySwapInvolved>
		</transactionCoding>
		<transactionAmounts>
			<transactionShares>
				<value>10000</value>
			</transactionShares>
			<transactionValue>
				<value>5.09</value>
			</transactionValue>
			<transactionAcquiredDisposedCode>
				<value>D</value>
			</transactionAcquiredDisposedCode>
		</transactionAmounts>
		<postTransactionAmounts>
			<sharesOwnedFollowingTransaction>
				<value>7381220.00</value>
			</sharesOwnedFollowingTransaction>
		</postTransactionAmounts>
		<ownershipNature>
			<directOrIndirectOwnership>
				<value>D</value>
			</directOrIndirectOwnership>
			<natureOfOwnership>
				<value/>
			</natureOfOwnership>
		</ownershipNature>
	</nonDerivativeSecurity>
	<nonDerivativeSecurity>
		<securityTitle>
			<value>Plug Power Inc. - Common Stock</value>
		</securityTitle>
		<transactionDate>
			<value>2003-05-09</value>
		</transactionDate>
		<transactionCoding>
			<transactionFormType>4</transactionFormType>
			<transactionCode>S</transactionCode>
			<equitySwapInvolved>0</equitySwapInvolved>
		</transactionCoding>
		<transactionAmounts>
			<transactionShares>
				<value>5000</value>
			</transactionShares>
			<transactionValue>
				<value>5.19</value>
			</transactionValue>
			<transactionAcquiredDisposedCode>
				<value>D</value>
			</transactionAcquiredDisposedCode>
		</transactionAmounts>
		<postTransactionAmounts>
			<sharesOwnedFollowingTransaction>
				<value>7376220.00</value>
			</sharesOwnedFollowingTransaction>
		</postTransactionAmounts>
		<ownershipNature>
			<directOrIndirectOwnership>
				<value>D</value>
			</directOrIndirectOwnership>
			<natureOfOwnership>
				<value/>
			</natureOfOwnership>
		</ownershipNature>
	</nonDerivativeSecurity>
	<footnotes>
	</footnotes>
	<ownerSignature>
		<signatureName>/s/ Mechanical Technology Incorporated,  </signatureName>
		<signatureDate>2003-05-12</signatureDate>
	</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
