Wisconsin Power and Light: To hold base rates flat in 2009

Media Contact: Rob Crain (608) 458-4469

Investor Relations: Jamie Freeman (608) 458-3274

Company, sharing pain of economic downturn, decides against filing for emergency rate relief

MADISON, WI – Despite a double digit drop in sales among nearly half of its top twenty customers, Wisconsin Power and Light Company (WPL), a subsidiary of Alliant Energy Corporation (NYSE: LNT), will hold base rates flat in 2009.

“While we believe the facts support the filing of an emergency rate relief request, we recognize the challenges the current economic downturn has placed on many of our customers,” said Barbara Swan, President-Wisconsin Power and Light. “We are hopeful this decision provides some stability to our customers – large and small – during this challenging time.”

In December 2008, it was announced that WPL’s projected retail sales were expected to be about six percent below the levels assumed in retail customer rates. Given the forward-looking test year that Wisconsin regulators use for rate-making purposes, the sudden and dramatic sales decline makes it nearly impossible for the company to recover costs authorized by the Public Service Commission of Wisconsin (PSCW) in its recent rate case.

“We have taken a series of actions to reduce costs in 2009, including freezing salaries at all levels of the company,” said Swan. “At the same time, we are committed to maintaining the necessary investments needed to provide a safe and reliable source of energy to our customers. This decision, and its potential economic impact, does not change that.”

As part of a rate case settlement announced in December 2008, WPL has the ability to request new rates to go into effect in January 2010. The company currently expects to file an application with the PSCW with such a request during the second quarter of this year. WPL also continues to monitor the fuel market for any price volatility which might warrant a fuel adjustment in 2009.

Alliant Energy’s 2009 earnings per share guidance that was issued in December and affirmed earlier this month did not include the potential positive impacts of emergency rate relief at WPL.