Exhibit 31.2

                                 CERTIFICATIONS

I, Robert D. Kelly, certify that:

    1. I have reviewed this quarterly report on Form 10-Q of Calpine Corporation
(the "registrant");

    2. Based on my knowledge,  this report does not contain any untrue statement
of a  material  fact or omit to  state a  material  fact  necessary  to make the
statements made, in light of the circumstances  under which such statements were
made, not misleading with respect to the period covered by this report;

    3. Based on my knowledge,  the  financial  statements,  and other  financial
information included in this report, fairly present in all material respects the
financial  condition,  results of operations and cash flows of the registrant as
of, and for, the periods presented in this report;

    4. The  registrant's  other  certifying  officer and I are  responsible  for
establishing and maintaining  disclosure  controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:

       a) Designed  such  disclosure  controls  and  procedures,  or caused such
    disclosure controls and procedures to be designed under our supervision,  to
    ensure that material information  relating to the registrant,  including its
    consolidated  subsidiaries,  is made  known  to us by  others  within  those
    entities,  particularly  during  the  period in which  this  report is being
    prepared;

       b) Evaluated the  effectiveness of the registrant's  disclosure  controls
    and  procedures  and  presented  in this  report our  conclusions  about the
    effectiveness  of the disclosure  controls and procedures,  as of the end of
    the period covered by this report based on such evaluation; and

       c)  Disclosed  in this  report  any change in the  registrant's  internal
    control over financial  reporting that occurred during the registrant's most
    recent fiscal quarter that has materially affected,  or is reasonably likely
    to materially  affect,  the  registrant's  internal  control over  financial
    reporting; and

    5. The registrant's other certifying officer and I have disclosed,  based on
our most recent evaluation of internal control over financial reporting,  to the
registrant's  auditors  and the audit  committee  of the  registrant's  board of
directors (or persons performing the equivalent functions):

       a) All significant  deficiencies and material weaknesses in the design or
    operation of internal control over financial  reporting which are reasonably
    likely to  adversely  affect the  registrant's  ability to record,  process,
    summarize and report financial information; and

       b) Any fraud, whether or not material,  that involves management or other
    employees who have a significant role in the  registrant's  internal control
    over financial reporting.

Date:  August 9, 2004

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