Alliant Energy: Proposed Wisconsin Power and Light plant rejected by state regulators

Media Contact: Rob Crain (608) 458-4469

Investor Relations: Jamie Freeman (608) 458-3274

Concerns remain about meeting Wisconsin energy needs

MADISON, WI – November 11, 2008 – The Public Service Commission of Wisconsin (PSCW) has rejected a proposal by Wisconsin Power and Light Company (WPL), a subsidiary of Alliant Energy Corporation (NYSE: LNT), to expand its existing Nelson Dewey Generating Station in Cassville, Wisconsin, to meet the future energy needs of its customers.

In a 3-0 oral decision, the PSCW denied WPL’s Certificate of Public Convenience and Necessity (CPCN) application. The PSCW stated that construction and operation of Nelson Dewey Unit 3 would not be the lowest cost option for customers. The PSCW also expressed concern regarding Nelson Dewey 3’s potential greenhouse gas emissions and its impact upon the environment.

“Our company is extremely disappointed in the PSCW’s decision today and the opportunities lost with it,” said Barbara Swan, President-WPL. “We will need to evaluate the PSCW’s decision prior to considering alternatives for our long-term generation growth strategy in Wisconsin .”

“However, today’s decision does not relieve us of our legal obligation to meet our customers rising energy needs, and we look forward to working with our regulators to come up with a viable alternative to ensure that those needs are met in a safe, reliable, affordable and environmentally responsibly manner,” added Swan. “We also want to express our gratitude for the support our proposal received from the community of Cassville, labor, agriculture, business, conservation groups and other political, economic and civic leaders across the state.”

The PSCW expects to issue its written order by December 15, 2008. The written order will provide additional details concerning the decision. WPL will have twenty days from the issuance of the written order to ask the PSCW to reconsider its decision.

Alliant Energy is an energy-services provider with subsidiaries serving approximately 1 million electric and over 400,000 natural gas customers. Providing its customers in the Midwest with regulated electric and natural gas service is the company’s primary focus. Wisconsin Power and Light, the company’s Wisconsin utility subsidiary, serves approximately 450,000 electric and 175,000 natural gas customers. Alliant Energy, headquartered in Madison, Wis., is a Fortune 1000 company traded on the New York Stock Exchange under the symbol LNT. For more information, visit the company’s Web site at