<SUBMISSION>
<ACCESSION-NUMBER>0001181431-03-021781
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20030806
<FILING-DATE>20030904
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>COOPER JOHN R
<CIK>0001168815
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1130
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>000-15472
<FILM-NUMBER>03880764
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O ENVIRONMENTAL POWER CORP
<STREET2>ONE CATE ST
<CITY>PORTSMOUTH
<STATE>NH
<ZIP>03801
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O ENVIRONMENTAL POWER CORP
<STREET2>ONE CATE ST
<CITY>PORTSMOUTH
<STATE>NH
<ZIP>03801
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ENVIRONMENTAL POWER CORP
<CIK>0000805012
<ASSIGNED-SIC>4991
<IRS-NUMBER>042782065
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>500 MARKET ST
<STREET2>STE 1E
<CITY>PORTSMOUTH
<STATE>NH
<ZIP>03801
<PHONE>6034311780
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>500 MARKET ST
<STREET2>STE 1E
<CITY>PORTSMOUTH
<STATE>NH
<ZIP>03801
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>rrd17771.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>3</documentType><periodOfReport>2003-08-06</periodOfReport>
    <noSecuritiesOwned>1</noSecuritiesOwned>

    <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><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>No Securities Owned</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value>None</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><ownerSignature><signatureName>/s/ John R. Cooper</signatureName><signatureDate>2003-09-04</signatureDate></ownerSignature></ownershipDocument>



</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
