Recent Press Release

Interstate Power and Light Company proud to support Iowa’s position as leader in wind energy production

Report cites Iowa as leader in percentage of wind-generated electricity on its grid in 2007

CEDAR RAPIDS, Iowa – April 2, 2008 – Today, the American Wind Energy Association announced that the State of Iowa led the nation in the percentage of wind-generated electricity on its grid in 2007. Interstate Power and Light Company (IPL), a subsidiary of Alliant Energy Corporation (NYSE: LNT), is proud to support Iowa’s commitment to being a renewable energy leader through its investments in wind power.

“Iowa’s energy future is bright and we commend Governor Culver’s team and other state and local leaders for their continued efforts to position Iowa as a leader in renewable energy,” says Tom Aller, president of IPL. “Our company is committed to investing approximately $450 million to further Iowa’s wind power development over the next three years. Wind power, along with other renewable energy resources, is leading the way in meeting part of our state’s future energy needs. We are proud to work with our renewable energy partners in Iowa to provide safe, reliable and environmentally responsible power to our customers. Wind power is good for our customers, economy and environment and we are proud to support its growth in Iowa.”

In February 2008, IPL announced plans to begin development of the ‘Whispering Willow Wind Farm’, located in Franklin County, Iowa. The Whispering Willow Wind Farm has the potential to produce up to 500 megawatts of emissions-free power if completely developed. IPL currently anticipates developing 200 megawatts of wind power on the site beginning in 2009. IPL expects the first 200 megawatts to be commercially operable in 2010. IPL will still have the ability to develop up to an additional 300 megawatts of potential wind power on the site. A decision regarding the development of the wind farm’s additional 300 megawatts has not yet been made.

Media Contact: Ryan Stensland (319) 786-4171