-----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,
 JMtw1H4F0AWyQgScKtSljbsB9Oj+CaQ3FTXCLYhrSCgp6NWkliwPodjJfC3YrYce
 k604HZe2Va5LN0RZNGGNUQ==

<SEC-DOCUMENT>0001181431-03-021866.txt : 20030904
<SEC-HEADER>0001181431-03-021866.hdr.sgml : 20030904
<ACCEPTANCE-DATETIME>20030904154506
ACCESSION NUMBER:		0001181431-03-021866
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030904
FILED AS OF DATE:		20030904

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			COOPER JOHN R
		CENTRAL INDEX KEY:			0001168815
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1130

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15472
		FILM NUMBER:		03881581

	BUSINESS ADDRESS:	
		STREET 1:		C/O ENVIRONMENTAL POWER CORP
		STREET 2:		ONE CATE ST
		CITY:			PORTSMOUTH
		STATE:			NH
		ZIP:			03801

	MAIL ADDRESS:	
		STREET 1:		C/O ENVIRONMENTAL POWER CORP
		STREET 2:		ONE CATE ST
		CITY:			PORTSMOUTH
		STATE:			NH
		ZIP:			03801

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ENVIRONMENTAL POWER CORP
		CENTRAL INDEX KEY:			0000805012
		STANDARD INDUSTRIAL CLASSIFICATION:	COGENERATION SERVICES & SMALL POWER PRODUCERS [4991]
		IRS NUMBER:				042782065
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 MARKET ST
		STREET 2:		STE 1E
		CITY:			PORTSMOUTH
		STATE:			NH
		ZIP:			03801
		BUSINESS PHONE:		6034311780

	MAIL ADDRESS:	
		STREET 1:		500 MARKET ST
		STREET 2:		STE 1E
		CITY:			PORTSMOUTH
		STATE:			NH
		ZIP:			03801
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd17806.xml
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-09-04</periodOfReport><notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000805012</issuerCik>
        <issuerName>ENVIRONMENTAL POWER CORP</issuerName>
        <issuerTradingSymbol>( powr )</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001168815</rptOwnerCik>
            <rptOwnerName>COOPER JOHN R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ENVIRONMENTAL POWER CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>ONE CATE STREET 4TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>PORTSMOUTH</rptOwnerCity>
            <rptOwnerState>NH</rptOwnerState>
            <rptOwnerZipCode>03801</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><derivativeTable><derivativeTransaction><securityTitle><value>2002 Director Options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>.66</value></conversionOrExercisePrice><transactionDate><value>2003-08-06</value></transactionDate><deemedExecutionDate><value>2003-08-06</value></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>100000</value></transactionShares><transactionPricePerShare><value>.66</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-08-06</value></exerciseDate><expirationDate><value>2013-08-06</value></expirationDate><underlyingSecur
ity><underlyingSecurityTitle><value>Common</value></underlyingSecurityTitle><underlyingSecurityShares><value>100000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>100000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction></derivativeTable><ownerSignature><signatureName>/s/ John R. Cooper</signatureName><signatureDate>2003-09-04</signatureDate></ownerSignature></ownershipDocument>



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