Independent arbitration panel validates TransAlta's operating

Independent arbitration panel validates TransAlta's operating
practices and grants claim of force majeure on Sundance unit 3 
CALGARY, ALBERTA -- (Marketwire) -- 11/23/12 -- TransAlta Corporation
(TransAlta) (TSX:TA)(NYSE:TAC) reported today an independent
arbitration panel granted TransAlta force majeure relief for derates
and outages in 2010 and 2011 related to mechanical failure of
critical generator components on Sundance unit 3. This decision
validates that the mechanical failure was beyond TransAlta's
reasonable control.  
"This decision further validates our good operating practices," said
Dawn Farrell, TransAlta President and CEO. "The circumstances of the
failure were unforeseen; we did what was necessary and prudent to
return the unit to service, maintain safe operations, and support the
reliability of the Alberta system." 
Background information: 
TransAlta took unit 3 of the Sundance facility out of service in May
2010 due to the mechanical failure of critical generator components.
Subsequently, TransAlta notified the Power Purchase Arrangement (PPA)
Buyers and claimed force majeure relief under the PPA. The PPA Buyer
rejected this claim, which was then referred to a binding arbitration
process under the dispute resolution process set out in the PPA and
in accordance with the Alberta Arbitration Act.  
Sundance 3 comprises 353 megawatts (MW) of the 2,126 MW Sundance
power plant, which has six individual units and serves as a baseload
facility for the Alberta electricity system. TransAlta commissioned
Unit 3 in 1976. Located about 70 kilometers west of Edmonton,
Sundance is the largest power plant in Alberta, and the largest coal
plant in Western Canada. 
TransAlta is a power generation and wholesale marketing company
focused on creating long-term shareholder value. TransAlta maintains
a low-to-moderate risk profile by operating a highly contracted
portfolio of assets in Canada, the United States and Australia.
TransAlta's focus is to efficiently operate geothermal, wind, hydro,
natural gas and coal facilities in order to provide customers with a
reliable, low-cost source of power. For over 100 years, TransAlta has
been a responsible operator and a proud contributor to the
communities in which it works and lives. TransAlta has been selected
by Jantzi-Sustainalytics as one of Canada's Top 50 Socially
Responsible Companies since 2009 and is recognized globally for its
leadership on sustainability and corporate responsibility standards
by FTSE4Good. TransAlta is Canada's largest investor-owned renewable
energy provider. 
This news release may contain forward looking statements, including
statements regarding the business and anticipated financial
performance of TransAlta Corporation. These statements are based on
TransAlta Corporation's belief and assumptions based on information
available at the time the assumption was made. These statements are
subject to a number of risks and uncertainties that may cause actual
results to differ materially from those contemplated by the
forward-looking statements. Some of the factors that could cause such
differences include, pricing in the market place, our inability to
enter into long term contracts due to prevailing market conditions,
legislative or regulatory developments, competition, global capital
markets activity, changes in interest rates, currency exchange rates,
inflation levels and general economic conditions in geographic areas
where TransAlta Corporation operates. 
Note: All financial figures are in Canadian dollars unless noted
otherwise.
Contacts:
Investor inquiries:
Jess Nieukerk
Director, Investor Relations
Phone: 1-800-387-3598 in Canada and U.S.
investor_relations@transalta.com 
Media inquiries:
Stacey Hatcher
Senior Corporate Relations Advisor
Cell: 587-216 2242
Toll-free media number: 1-855-255-9184
Local number: 403-267-2540