Calpine, Entergy Texas Enter 10-Year Power Purchase Agreement

Calpine Energy Services, L.P., a subsidiary ofCalpine
Corporation (NYSE:CPN), has signed a 10-year power purchase agreement
(PPA) to provide 485 megawatts of power from its Carville Energy Center
to Entergy Services, Inc., as agent for Entergy Texas, Inc., beginning
in June 2012.

Entergy Gulf States Louisiana, L.L.C., currently purchases the
electrical output of the natural gas-fired Carville Energy Center,
located in St. Gabriel, Louisiana. Calpine won the new PPA through a
competitive process that resulted from the 2009 Request for Proposals
for Long-term Supply Side Resources issued by Entergy Services. Under
the PPA, Calpine will provide Entergy Texas with a blend of baseload,
intermediate and peaking capacity and energy and ancillary products.

'We are pleased to continue our productive relationship with Entergy,?
said Heather Hazen, Calpine′s Vice President of Strategic Origination
for its South Region. 'This agreement illustrates the value of natural
gas-fired generation in terms of dispatch flexibility to meet our
customers′ quickly changing load needs.?

Carville Energy Center, which commenced commercial operation in June
2003, is a highly efficient cogeneration power plant. Using modern,
combined-cycle technology, Carville consumes approximately 34 percent
less natural gas and emits 85 percent less nitrous oxide per megawatt
hour generated than the average fossil-fueled power plant in Louisiana.
In addition to generating electricity, Carville provides steam for
industrial processing to Cos-Mar Incorporated under a long-term contract.

Under the PPA, Entergy Texas will purchase the plant′s full output at
summer-rated conditions. Entergy Texas will sell one-half of the power
purchased under the PPA to Entergy Gulf States Louisiana. The PPA is
conditioned on regulatory approval by the Louisiana Public Service
Commission of that sale and on securing satisfactory transmission.

About Calpine

Founded in 1984, Calpine Corporation is a major U.S. power company,
currently capable of delivering approximately 28,000 megawatts of clean,
cost-effective, reliable and fuel-efficient power from its 92 operating
plants to customers and communities in 20 U.S. states and Canada.
Calpine Corporation is committed to helping meet the needs of an economy
that demands more and cleaner sources of electricity. Calpine owns,
leases and operates primarily low-carbon, natural gas-fired and
renewable geothermal power plants. Using advanced technologies, Calpine
generates power in a reliable and environmentally responsible manner for
the customers and communities it serves. Please visit our website at www.calpine.com
for more information.

Forward-Looking Information

In addition to historical information, this release contains
forward-looking statements within the meaning of Section 27A of the
Securities Act of 1933, as amended, and Section 21E of the Securities
Exchange Act of 1934, as amended. Words such as 'believe,? 'intend,?
'expect,? 'anticipate,? 'plan,? 'may,? 'will? and similar expressions
identify forward-looking statements. Such statements include, among
others, those concerning expected financial performance and strategic
and operational plans, as well as assumptions, expectations,
predictions, intentions or beliefs about future events. You are
cautioned that any such forward-looking statements are not guarantees of
future performance and that a number of risks and uncertainties could
cause actual results to differ materially from those anticipated in the
forward-looking statements. Please see the risks identified in this
release or in Calpine′s reports and registration statements filed with
the Securities and Exchange Commission, including, without limitation,
the risk factors identified in its Annual Report on Form 10-K for the
year ended December 31, 2010, and its Quarterly Report on Form 10-Q for
the quarter ended March 31, 2011. These filings are available by
visiting the Securities and Exchange Commission′s website at www.sec.gov
or Calpine′s website at www.calpine.com.
Actual results or developments may differ materially from the
expectations expressed or implied in the forward-looking statements, and
Calpine undertakes no obligation to update any such statements.

Calpine

Media Relations:

Norma F. Dunn,
713-830-8883

norma.dunn@calpine.com

or

Investor
Relations:

Christine Parker, 713-830-8775

christine.parker@calpine.com