<SUBMISSION>
<ACCESSION-NUMBER>0001181431-12-008232
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20120213
<FILING-DATE>20120213
<DATE-OF-FILING-DATE-CHANGE>20120213
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PHOEBE SNOW FOUNDATION
<CIK>0001252480
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-12079
<FILM-NUMBER>12600788
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>591 REDWOOD HIGHWAY
<STREET2>STE 3215
<CITY>MILL VALLEY
<STATE>CA
<ZIP>94941
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>CALPINE CORP
<CIK>0000916457
<ASSIGNED-SIC>4911
<IRS-NUMBER>770212977
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>717 TEXAS AVENUE
<STREET2>SUITE 1000
<CITY>HOUSTON
<STATE>TX
<ZIP>77002
<PHONE>7138302000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>717 TEXAS AVENUE
<STREET2>SUITE 1000
<CITY>HOUSTON
<STATE>TX
<ZIP>77002
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>SPO ADVISORY CORP
<CIK>0000919468
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-12079
<FILM-NUMBER>12600789
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>591 REDWOOD HIGHWAY
<STREET2>SUITE 3215
<CITY>MILL VALLEY
<STATE>CA
<ZIP>94941
<PHONE>4153836600
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>591 REDWOOD HIGHWAY
<STREET2>SUITE 3215
<CITY>MILL VALLEY
<STATE>CA
<ZIP>94941
</MAIL-ADDRESS>
<FORMER-NAME>
<FORMER-CONFORMED-NAME>SF ADVISORY CORP
<DATE-CHANGED>19990329
</FORMER-NAME>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd334103.xml
<DESCRIPTION>STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-02-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000916457</issuerCik>
        <issuerName>CALPINE CORP</issuerName>
        <issuerTradingSymbol>CPN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000919468</rptOwnerCik>
            <rptOwnerName>SPO ADVISORY CORP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>591 REDWOOD HIGHWAY, SUITE 3215</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MILL VALLEY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94941</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252480</rptOwnerCik>
            <rptOwnerName>PHOEBE SNOW FOUNDATION</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>591 REDWOOD HIGHWAY , SUITE 3215</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MILL VALLEY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94941</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-02-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>16800000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.57</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>77472508</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The entities and individuals directly selling these shares reported in this filing are SPO Partners II, L.P. (&quot;SPO Partners&quot;), which sold 15,261,300, SPO Partners II Co-Investment Partnership, L.P. (&quot;SPO Co-Invest&quot;), which sold 916,100 shares, San Francisco Partners, L.P. (&quot;SF Partners&quot;), which sold 583,500 shares, John H. Scully (&quot;JHS&quot;), who sold 1,100 shares, William E. Oberndorf (&quot;WEO&quot;), who sold 6,200 shares, Edward H. McDermott (&quot;EHM&quot;), who sold 1,200 shares and Phoebe Snow Foundation (&quot;PSF&quot;), which sold 30,600 shares.  The price for the sales on 2/13/12, reported in Line 1 above, was $15.57</footnote>
        <footnote id="F2">As a result of the sales causing this filing 70,541,012 shares are owned directly by SPO Partners, and may be deemed to be indirectly beneficially owned by (i) SPO Advisory Partners, L.P. (&quot;SPO Advisory&quot;), the sole general partner of SPO Partners, (ii) SPO Advisory Corp. (&quot;SPO Corp.&quot;), the sole general partner of SPO Advisory, and (iii) JHS, WEO, and EHM, the three controlling persons of SPO Corp. Additionally, as a result of the sales causing this filing, 4,234,400 shares are owned directly by SPO Co-Invest, and may be deemed to be indirectly beneficially owned by (i) SPO Advisory, the sole general partner of SPO Co-Invest, (ii) SPO Corp, the sole general partner of SPO Advisory, and (iii) JHS, WEO, and EHM, the three controlling persons of SPO Corp.</footnote>
        <footnote id="F3">Additionally, as a result of the sales causing this filing, 2,697,096 shares are owned directly by SF Partners, and may be deemed to be indirectly beneficially owned by (i) SF Advisory Partners, L.P. (&quot;SF Advisory&quot;), the sole general partner of SF Partners, (ii) SPO Corp., the sole general partner of SF Advisory, and (iii) JHS, WEO, and EHM, the three controlling persons of SPO Corp. Additionally, as a result of the sales causing this filing, JHS owns 5,000 shares in his IRAs, which are self-directed, WEO owns 28,700 shares in his IRA, which is self-directed, EHM owns 5,600 shares in his IRA, which is self-directed and PSF owns 141,500 shares.</footnote>
        <footnote id="F4">Additionally, 5,451 restricted stock units are owned by WEO, a director of the Issuer. Pursuant to the partnership agreement governing SPO Partners, these shares may be deemed to be indirectly beneficially owned by SPO Partners together with any profits arising therefrom.</footnote>
        <footnote id="F5">Additionally, the shares represented in Column 5 above may be deemed to be indirectly beneficially owned by J. Stuart Ryan (&quot;JSR&quot;), solely in his advisory capacity to SPO Corp.  Additionally, 5,029 shares of common stock and 23,802 restricted stock units are owned by JSR, a director of the Issuer.</footnote>
    </footnotes>

    <remarks>Form 2 of 2

The individuals and entities listed in the note above may be deemed to form a &quot;group&quot;, as such term is defined in Rule 13d-5(b)(1) promulgated under the Securities Exchange Act of 1934, for purposes of this filing.  This filing shall not be deemed as an admission by any such person that such person is, for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, the beneficial owner of any equity securities covered by this statement.  Each such person disclaims beneficial ownership of the reported securities except to the extent of such person's pecuniary interest, if any, therein.</remarks>

    <ownerSignature>
        <signatureName>Kim M. Silva, Attorney-in-Fact</signatureName>
        <signatureDate>2012-02-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
