Exhibit 32.1

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002



     In  connection  with the  Quarterly  Report  of  Calpine  Corporation  (the
"Company")  on Form 10-Q for the period  ending June 30, 2004, as filed with the
Securities and Exchange  Commission on the date hereof (the  "Report"),  each of
the undersigned does hereby certify,  pursuant to 18 U.S.C. ss. 1350, as adopted
pursuant to ss. 906 of the  Sarbanes-Oxley Act of 2002, that, to the best of his
knowledge, based upon a review of the Report:

     (1) The Report fully  complies  with the  requirements  of Section 13(a) or
15(d) of the Securities Exchange Act of 1934; and

     (2)  The  information  contained  in the  Report  fairly  presents,  in all
material  respects,  the  financial  condition  and results of  operation of the
Company.


/s/ Peter Cartwright                   /s/ Robert D. Kelly
- -----------------------------          -----------------------------
Peter Cartwright                       Robert D. Kelly
Chairman, President and                Executive Vice President and
Chief Executive Officer                Chief Financial Officer
Calpine Corporation                    Calpine Corporation


Dated:  August 9, 2004


A signed  original of this  written  statement  required by Section 906 has been
provided to Calpine  Corporation and will be retained by Calpine Corporation and
furnished to the Securities and Exchange Commission or its staff upon request.