                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


                                    FORM 11-K

         (Mark One)

            [X]      ANNUAL REPORT PURSUANT TO SECTION 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                   For the fiscal year ended December 31, 2004

                                       OR

            [ ]  TRANSITION REPORT PURSUANT TO SECTION 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                   For the transition period from ____ to ____

                         Commission file number 1-12079

                   CALPINE CORPORATION RETIREMENT SAVINGS PLAN
                        (EIN 77-0212977 PLAN NUMBER 002)
                            (Full title of the plan)

                               CALPINE CORPORATION
                           50 WEST SAN FERNANDO STREET
                           SAN JOSE, CALIFORNIA 95113
         (Name of issuer of the securities held pursuant to the plan and
                 the address of its principal executive office)




<PAGE>


Required Information

Financial Statements:
---------------------

Statements of Net Assets Available for Benefits as of December 31, 2004 and 2003

Statement  of Changes in Net Assets  Available  for  Benefits for the Year Ended
December 31, 2004

Notes to Financial Statements

Other:*

Schedule H,  Part IV,  Line 4i,  Form 5500 -- Schedule of Assets (Held at End of
Year) at December 31, 2004

*    Other schedules required by 29 CFR 2520.103-10 of the Department of Labor's
     Rules and  Regulations  for  Reporting  and  Disclosure  under the Employee
     Retirement Income Security Act of 1974 ("ERISA") have been omitted, because
     they are not applicable.

Exhibit 23.1 - Consent of  PricewaterhouseCoopers  LLP,  Independent  Registered
     Public Accounting Firm


<PAGE>


                                   SIGNATURES

The Plan.  Pursuant to the requirements of the Securities  Exchange Act of 1934,
the trustees (or other persons who  administer  the employee  benefit plan) have
duly  caused this  annual  report to be signed on its behalf by the  undersigned
hereunto duly authorized.

                   CALPINE CORPORATION RETIREMENT SAVINGS PLAN

             Date: June 29, 2005     By:  /s/ Peter Cartwright
                                          --------------------
                                          Peter Cartwright
                                          Chairman of the Board of Directors of
                                          Calpine Corporation


<PAGE>



Calpine Corporation
Retirement Savings Plan
Financial Statements and Supplemental Schedule
December 31, 2004 and 2003






<PAGE>



Calpine Corporation
Retirement Savings Plan
Index to Financial Statements and Supplemental Schedule
--------------------------------------------------------------------------------


<TABLE>
<CAPTION>
                                                                                            Page
<S>                                                                                         <C>
Report of Independent Registered Public Accounting Firm....................................   1

Financial Statements

   Statements of Net Assets Available for Benefits at December 31, 2004 and 2003...........   2

   Statement of Changes in Net Assets Available for Benefits
       for the Year Ended December 31, 2004................................................   3

   Notes to Financial Statements........................................................... 4-7

Supplemental Schedule:*

   Schedule H, Part IV, Line 4i, Form 5500 -- Schedule of Assets (Held at End of
       Year) at December 31, 2004..........................................................   8


*    Other schedules required by 29 CFR 2520.103-10 of the Department of Labor's
     Rules and  Regulations  for  Reporting  and  Disclosure  under the Employee
     Retirement Income Security Act of 1974 ("ERISA") have been omitted, because
     they are not applicable.
</TABLE>




<PAGE>



             Report of Independent Registered Public Accounting Firm


To the Participants and Administrator of
Calpine Corporation Retirement Savings Plan


In our opinion, the accompanying statements of net assets available for benefits
and the  related  statement  of  changes in net assets  available  for  benefits
present fairly, in all material respects,  the net assets available for benefits
of Calpine Corporation Retirement Savings Plan (the "Plan") at December 31, 2004
and December 31, 2003, and the changes in net assets  available for benefits for
the year ended  December  31,  2004 in  conformity  with  accounting  principles
generally accepted in the United States of America.  These financial  statements
are the  responsibility  of the  Plan's  management.  Our  responsibility  is to
express  an  opinion  on these  financial  statements  based on our  audits.  We
conducted our audits of these statements in accordance with the standards of the
Public Company  Accounting  Oversight  Board (United  States).  Those  standards
require that we plan and perform the audit to obtain reasonable  assurance about
whether the financial  statements  are free of material  misstatement.  An audit
includes  examining,  on a test  basis,  evidence  supporting  the  amounts  and
disclosures in the financial  statements,  assessing the  accounting  principles
used and  significant  estimates made by management,  and evaluating the overall
financial  statement  presentation.   We  believe  that  our  audits  provide  a
reasonable basis for our opinion.

Our audits  were  conducted  for the  purpose of forming an opinion on the basic
financial statements taken as a whole. The supplemental Schedule of Assets (Held
at End of Year) is presented for the purpose of additional analysis and is not a
required part of the basic financial statements but is supplementary information
required by the  Department of Labor's Rules and  Regulations  for Reporting and
Disclosure  under the Employee  Retirement  Income  Security  Act of 1974.  This
supplemental  schedule  is the  responsibility  of the  Plan's  management.  The
supplemental  schedule has been subjected to the auditing  procedures applied in
the audit of the basic  financial  statements  and,  in our  opinion,  is fairly
stated in all material  respects in relation to the basic  financial  statements
taken as a whole.



/s/ PricewaterhouseCoopers LLP


San Francisco, California
June 27, 2005









































                                       -1-
<PAGE>



Calpine Corporation
Retirement Savings Plan
Statements of Net Assets Available for Benefits
--------------------------------------------------------------------------------





                                                        December 31,
                                              ---------------------------------
                                                   2004                2003
                                              -------------       -------------
Assets
   Investments, at fair value (Note 3)....... $ 138,889,304       $ 107,827,940
   Participant loans.........................     4,107,295           3,090,261
                                              -------------       -------------
      Total investments......................   142,996,599         110,918,201
Non-interest bearing cash....................       177,456              18,254
                                              -------------       -------------
      Total assets...........................   143,174,055         110,936,455

Liabilities
Other liabilities............................        19,890                  --
                                              -------------       -------------
      Net assets available for benefits...... $ 143,154,165       $ 110,936,455
                                              =============       =============
























































   The accompanying notes are an integral part of these financial statements.


                                       -2-
<PAGE>



Calpine Corporation
Retirement Savings Plan
Statement of Changes in Net Assets Available for Benefits
--------------------------------------------------------------------------------





                                                                      For the
                                                                     Year Ended
                                                                    December 31,
                                                                        2004
                                                                   -------------
Additions to net assets attributed to investment income
   Net appreciation in fair value of investments (Note 3).......   $   3,414,398
   Interest and dividends.......................................         262,672
   Interest income from participant loans.......................         259,766
                                                                   -------------
        Total investment income.................................       3,936,836

Contributions
   Participants.................................................      19,852,566
   Company......................................................      12,433,043
   Rollovers....................................................       2,644,189
                                                                   -------------
        Total contributions.....................................      34,929,798
                                                                   -------------
        Total additions.........................................      38,866,634
                                                                   -------------
Deductions from net assets attributed to
   Benefits paid to participants................................       6,561,633
   Administrative expenses (Note 4).............................          87,291
                                                                   -------------
        Total deductions........................................       6,648,924
                                                                   -------------
        Net increase............................................      32,217,710
                                                                   -------------
Net assets available for benefits
   Beginning of year............................................     110,936,455
                                                                   -------------
   End of year..................................................   $ 143,154,165
                                                                   =============








































   The accompanying notes are an integral part of these financial statements.


                                       -3-
<PAGE>


Calpine Corporation
Retirement Savings Plan
Notes to Financial Statements
--------------------------------------------------------------------------------


1.   Description of the Plan and Investment Program

     The following  description of the Calpine  Corporation  Retirement  Savings
     Plan (the "Plan") provides only general  information.  Participants  should
     refer to the Plan  agreement for a more complete  description of the Plan's
     provisions.

     General
     Calpine Corporation (the "Company")  established the Plan effective January
     1, 1987 to supplement  employees'  retirement income. All active employees,
     with the  exception of  collective  bargaining  employees,  are eligible to
     participate  in the Plan from the date of hire.  The Plan is subject to the
     provisions  of  the  Employee   Retirement  Income  Security  Act  of  1974
     ("ERISA").  The  Plan  is  directly  monitored  by the  Advisory  Committee
     appointed by the Board of Directors.  Fidelity  Management Trust Company is
     the Plan trustee. Arnerich Massena & Associates are the investment advisors
     to the Plan.

     Participant and Company Contributions
     The Plan offers  participants  the option of  contributing  pre-tax  and/or
     after-tax  dollars under Section 401(k) of the Internal  Revenue Code. Each
     year,  participants  may  contribute  up to an  annual  maximum  of  15% of
     eligible  compensation  on an after-tax  basis or an annual  maximum of the
     lesser of 60% of eligible  compensation  or $13,000 on a pre-tax  basis for
     2004. Participants who were 50 years of age or older at the end of calendar
     year 2004 were also eligible to make pre-tax "catch-up contributions" up to
     $3,000.  Employee pre-tax  contributions from 1% to 100% can be made on any
     employer-paid  bonus. For each payroll period, the Company makes a matching
     contribution equal to 4% of the employees'  eligible  compensation for such
     payroll period,  as defined by the Plan agreement.  The Company may, at its
     discretion,  make  additional  annual profit sharing  contributions  to the
     Plan.  For the year ended  December 31, 2004,  the Company did not make any
     additional  profit-sharing  contributions.  The amount  contributed  by the
     employee and on behalf of the employees by the Company for a given year may
     not  exceed  the  lesser  of  $40,000  or  100%  of the  employees'  annual
     compensation.

     Participant Accounts
     Each  participant has the right to direct the investment of his/her account
     balance and contributions to various investment  options,  all of which are
     managed by Fidelity  Investments.  The  investment  options are provided to
     allow  participants a choice as to investment  elections.  Participants may
     change the allocation of their contributions on a daily basis. In addition,
     participants  may borrow from their accounts in accordance  with the Plan's
     provisions.  Each participant's  account is credited with the participant's
     contribution and allocations of (a) the Company's contribution and (b) plan
     earnings,  and charged with an allocation of  administrative  expenses,  as
     defined in the Plan document.

     Vesting
     Participants are fully vested in their account  balances for  contributions
     made to the participant's account by both the Company and by the employee.

     Participant Loans
     Participants  are  allowed  to have one loan  outstanding  at any one time.
     Loans are limited to the lesser of $50,000 or one-half of the participant's
     vested balance,  and are secured by his/her account balance.  Loans must be
























                                       -4-
<PAGE>


Calpine Corporation
Retirement Savings Plan
Notes to Financial Statements
--------------------------------------------------------------------------------


     for a minimum of $1,000.  Participants  can obtain loans with a term of ten
     years if the loans are used for the purpose of  acquiring  their  principal
     residence.  The term of all other loans shall not extend beyond five years.
     Interest rates on the loans outstanding at December 31, 2004 range from 4.5
     percent to 9.75  percent.  Principal  and interest is paid ratably  through
     biweekly payroll deductions.

     Payments of Benefits
     Participant  accounts are payable upon disability,  death or termination of
     employment with the Company.  Upon termination of employment,  participants
     may receive a lump-sum  payment of their  account  balances  subject to the
     vesting  provisions  described  above.  Additional  optional payment forms,
     including a qualified  joint and  survivor  annuity,  are  available at the
     election of the participant.  If the value of the participant's  account is
     less than  $5,000,  the  payment  will be made in a lump sum.  Any  taxable
     distribution  paid  by the  trustee  directly  to the  participant  will be
     subject to mandatory federal income tax withholding of 20% of the requested
     distribution.

     Administrative Expenses
     Investment   management  fees,  trustee  fees,  agent  fees  and  brokerage
     commissions  are  paid by the  Plan  and are  allocated  to the  individual
     participant   accounts.   Other  outside  professional  and  administrative
     services  are paid or  provided  by the  Company to the extent they are not
     covered by the Plan.


2.   Summary of Significant Accounting Policies

     Basis of Accounting
     The  accompanying  financial  statements  of the Plan are  prepared  on the
     accrual  basis of  accounting  in  accordance  with  accounting  principles
     generally accepted in the United States of America.

     Use of Estimates
     The  preparation  of financial  statements  in conformity  with  accounting
     principles  generally  accepted in the United  States of America,  requires
     management  to make  estimates  and  assumptions  that affect the  reported
     amounts of assets and  liabilities  and changes  therein and  disclosure of
     contingent  assets and liabilities.  Actual results could differ from those
     estimates.

     Investment Valuation and Income Recognition
     Investments  in mutual  funds are  stated at fair value  based on  publicly
     quoted market prices.  Calpine  Corporation common stock, a publicly traded
     security,  is valued at fair value based upon the last reported sales price
     on the last business day of the Plan year. Loans to participants are valued
     at cost, which  approximates fair value.  Interest income is recorded on an
     accrual  basis.  Dividend  income  is  recorded  on the  ex-dividend  date.
     Purchases and sales of securities are recorded on a trade-date  basis.  The
     Plan  presents  in the  Statement  of Changes in Net Assets  Available  for
     Benefits  the  net  appreciation   (depreciation)  in  fair  value  of  its
     investments,  which consists of the realized gains or losses and unrealized
     appreciation or depreciation on those investments.

     Risks and Uncertainties
     In general,  investment  securities are exposed to various  risks,  such as
     interest rate, credit and overall market volatility risks. Due to the level
     of risk associated  with certain  investment  securities,  it is reasonably
     possible that changes in the values of investment securities could occur in





















                                       -5-
<PAGE>


Calpine Corporation
Retirement Savings Plan
Notes to Financial Statements
--------------------------------------------------------------------------------


     the near  term,  and such  changes  could  materially  affect  the  amounts
     reported  in the  Statements  of Net  Assets  Available  for  Benefits  and
     Statement of Changes in Net Assets Available for Benefits.

     Payment of Benefits
     Benefits are recorded when paid.


3.   Investments

     The following investments held by the Plan represented 5% or more of the
     Plan's net assets:

                                                           December 31,
                                                   ----------------------------
                                                       2004              2003
                                                   -----------      -----------

Calpine Corporation common stock.............      $24,477,234      $23,031,642
Fidelity Magellan Fund.......................       15,600,909       13,632,361
Fidelity Overseas Fund.......................        7,299,951        4,288,903
Fidelity Aggressive Growth Fund..............       10,778,955        8,414,004
Fidelity Balanced Fund.......................       16,583,131       11,380,596
Fidelity Equity Income II Fund...............       11,408,494        7,883,421
Fidelity Retirement Money Market Fund........       24,868,272       22,135,183

     During  2004,  the  Plan's  investments  (including  gains  and  losses  on
     investments  bought and sold, as well as held during the year)  appreciated
     in value by $3,414,398 as follows:

                                                                    Year Ended
                                                                   December 31,
                                                                       2004
                                                                   ------------
Mutual funds....................................................   $  7,592,643
Calpine Corporation common stock................................     (4,178,245)
                                                                   ------------
   Net appreciation in fair value of investments.................  $  3,414,398
                                                                   ============

The Plan invests in Calpine Corporation common stock in a unitized trust fund.


4.   Party-In-Interest Transactions

     The trustee is a party-in-interest according to Section 3(14) of ERISA. The
     trustee serves as Plan  recordkeeper,  investment  manager and custodian to
     the Plan.  As defined by ERISA,  any person or  organization  that provides
     these services to the Plan is a party-in-interest. Fees paid by the Plan to
     the trustee amounted to $87,291 for the year ended December 31, 2004.


5.   Plan Termination

     Although  it has not  expressed  any intent to do so, the  Company  has the
     right under the Plan to discontinue  its  contributions  at any time and to
     terminate the Plan,  subject to the  provisions of ERISA.  In the event the
























                                       -6-
<PAGE>


Calpine Corporation
Retirement Savings Plan
Notes to Financial Statements
--------------------------------------------------------------------------------


     Plan  should  terminate,   the  Plan   administrator  will  facilitate  the
     distribution of account balances under the provisions of the Plan agreement
     until all assets have been distributed by the trustee.


6.   Tax Status

     The Internal  Revenue  Service has determined and informed the Company by a
     letter dated  December 12,  2001,  that the Plan and its related  trust are
     designed in accordance with the applicable sections of the Internal Revenue
     Code ("IRC").  The Plan has been amended since receiving the  determination
     letter.  However, the Plan administrator and the Plan's tax counsel believe
     that the Plan is designed and is  currently  being  operated in  compliance
     with the applicable  provisions of the IRC.  Accordingly,  no provision for
     federal  income  taxes  has  been  made  in  the   accompanying   financial
     statements.


7.   Concentration of Risk

     A portion of the Plan's  assets is invested in the common  stock of Calpine
     Corporation,  which represents 17.1% of the Plan's total assets at December
     31, 2004.  Calpine  Corporation  common stock held by the Plan decreased in
     value by $4.2 million for the year ended December 31, 2004.

























































                                       -7-
<PAGE>





                              Supplemental Schedule




<PAGE>


Calpine Corporation
Retirement Savings Plan
I.R.S. Employer Identification No. 77-0212977
Schedule H, Part IV, Line 4i, Form 5500 -- Schedule of Assets
  (Held at End of Year) at December 31, 2004
--------------------------------------------------------------------------------

<TABLE>
<CAPTION>
 (a)                        (b)                                                 (c)                        (d)          (e)
               Identity of Issuer, Borrower,                                                                          Current
                  Lessor or Similar Party                            Description of Investment             Cost        Value
 ----    -------------------------------------------       --------------------------------------------    ----     ------------
  <S>                                                      <C>                                              <C>     <C>
  *      Calpine Corporation unitized stock fund           Cash                                             **      $    582,668
  *      Calpine Corporation unitized stock fund           6,212,496 shares of common stock                 **        24,477,234
  *      Fidelity Magellan Fund                            150,312 shares of mutual fund investments        **        15,600,909
  *      Fidelity Aggressive Growth Fund                   649,355 shares of mutual fund investments        **        10,778,955
  *      Fidelity Balanced Fund                            930,591 shares of mutual fund investments        **        16,583,131
  *      Fidelity Overseas Fund                            206,330 shares of mutual fund investments        **         7,299,951
  *      Fidelity Equity Income II Fund                    475,156 shares of mutual fund investments        **        11,408,494
  *      Fidelity Retirement Money Market Fund             24,868,272 shares of mutual fund investments     **        24,868,272
  *      Fidelity Intermediate Bond Fund                   666,781 shares of mutual fund investments        **         7,014,541
         Artisan Mid Cap Investment                        185,843 shares of mutual fund investments        **         5,493,523
         Brown Capital Management Small Company Fund       128,318 shares of mutual fund investments        **         3,823,893
         Sterling Capital Small Cap Value Fund             305,255 shares of mutual fund investments        **         5,686,904
         Spartan US Equity Index                           122,978 shares of mutual fund investments        **         5,270,829
  *      591 Participant loans                             Interest rates, 4.5% to 9.75%                    **         4,107,295
                                                                                                                   -------------
                                                                                                                    $142,996,599
<FN>
*    Party-in-interest for which a statutory exemption exists.
**   Under ERISA, reporting the cost of an asset held for investment purposes is not required for participant-directed investments.
</FN>
</TABLE>




















































                                       -8-
<PAGE>



EXHIBIT 23.1


            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
            --------------------------------------------------------

We  hereby  consent  to the  incorporation  by  reference  in  the  Registration
Statement on Form S-8 (Nos. 333-34002 and 333-115487) of Calpine Corporation  of
our report dated June 27, 2005 relating to the  financial  statements of Calpine
Corporation Retirement Savings Plan, which appears in this Form 11-K.



/s/ PricewaterhouseCoopers LLP


San Francisco, California
June 27, 2005
