UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


                                    FORM 8-K

                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of

                       the Securities Exchange Act of 1934


         Date of Report (Date of earliest event reported): May 31, 2002


                               CALPINE CORPORATION

                            (A Delaware Corporation)

                        Commission File Number: 001-12079

                  I.R.S. Employer Identification No. 77-0212977


                           50 West San Fernando Street

                           San Jose, California 95113

                            Telephone: (408) 995-5115





ITEM 5.  OTHER EVENTS

     On May 31, 2002, Calpine Corporation reported that it did not engage in any
"roundtrip"  or "wash" power  trading  activities  for the purpose of increasing
volumes or revenue,  impacting market prices, or for any other improper business
purpose.  Calpine's  report is in response to the May 21, 2002,  data request by
the Federal Energy Regulatory  Commission  (FERC),  investigating  power trading
activities  in the U.S.  portion of the  Western  Systems  Coordinating  Council
during 2000 and 2001.

ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS

(a)      Not applicable.

(b)      Not applicable.

(c)      Exhibits.

         99.0 Press release dated May 31, 2002 - Calpine Response to FERC


SIGNATURES

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.


                               CALPINE CORPORATION


                          By: /s/ Charles B. Clark, Jr.
                              -------------------------
                              Charles B. Clark, Jr.
                      Senior Vice President and Controller
                            Chief Accounting Officer

Date:  June 3, 2002







EXHIBIT 99.0

NEWS RELEASE CONTACTS:                                              408/995-5115
                                         Media Relations: Bill Highlander, X1244
                                         Investor Relations: Rick Barraza, X1125


                    CALPINE RESPONDS TO FERC'S DATA REQUEST;
               REPORTS NO IMPROPER "ROUNDTRIP" TRADING ACTIVITIES

     (SAN JOSE,  CALIF.) May 31,  2002 - Calpine  Corporation  [NYSE:CPN]  today
reported  that it did not  engage in any  "roundtrip"  or "wash"  power  trading
activities for the purpose of increasing  volumes or revenue,  impacting  market
prices,  or for any other  improper  business  purpose.  Calpine's  report is in
response  to the May 21,  2002 data  request by the  Federal  Energy  Regulatory
Commission (FERC), investigating power trading activities in the U.S. portion of
the Western Systems Coordinating Council during 2000 and 2001.

     Calpine conducted a thorough review of all subject transactions during this
period.  Of the more than 72,000  transactions,  31 resulted in the simultaneous
purchase   and  sale  of  the  same   electricity   product   between  the  same
counterparties.  These transactions were completed for risk management  reasons,
and  represented  approximately  one-tenth of one percent of 2001 total revenue.
There were no such transactions in 2000.

     Calpine will continue to examine its trading activities to ensure they meet
Calpine's high standards of business conduct. The company will respond to FERC's
May 22, 2002 gas trading data request by June 5, 2002.

     Calpine  is a fully  integrated  independent  power  company.  Its  primary
business is developing and operating electric generating facilities. The company
manages every aspect of a power generating  facility - from development  through
design,  engineering and construction management,  into operations,  fuel supply
and power sales.  The company's power marketing focus is on utilizing  long-term
contracts  for the sale of power,  optimizing  the value of its own  assets  and
managing risk.

     A copy of  Calpine's  response  to the FERC will be made  available  on the
investor relations page of the company's website at www.calpine.com.

     Based in San Jose,  Calif.,  Calpine  Corporation is a leading  independent
power company that is dedicated to providing  customers  with clean,  efficient,
natural  gas-fired  power  generation.  It generates and markets power,  through
plants it develops,  owns and operates, in 21 states in the United States, three
provinces  in Canada  and in the United  Kingdom.  Calpine  also is the  world's
largest producer of renewable  geothermal energy, and it owns 1.3 trillion cubic
feet  equivalent of proved natural gas reserves in Canada and the United States.
The company  was  founded in 1984 and is  publicly  traded on the New York Stock
Exchange under the symbol CPN. For more  information  about  Calpine,  visit its
website at www.calpine.com.