Alliant Energy: Kathleen Lipp announces retirement

Media Contact: Scott Reigstad (608) 458-3145

Doug Kopp to take over as Chief Environmental Officer

MADISON, WI – December 22, 2010 – After 31 years of serving Alliant Energy (NYSE: LNT) customers in a variety of positions, most recently that of Chief Environmental Officer, Kathleen Lipp has announced her retirement, effective March 2011.

Lipp, who has held her current position since 2004, has been responsible for environmental compliance and management, emerging issues evaluation, and new program development and implementation support. Serving a vital role for both Alliant Energy and the communities in which it serves, Lipp has made a lasting impact.

“Kathy has played an integral role in the oversight of our environmental policy and performance,” said Bill Harvey, Alliant Energy Chairman, President and CEO. “Her leadership and professionalism are hallmarks of her tenure. Although we will miss her as part of the Alliant Energy family, we want to thank and congratulate her for her many contributions.”

Succeeding Lipp as Chief Environmental Officer is Doug Kopp. Kopp has served in a variety of roles with Alliant Energy since 1992, including various positions in delivery and generation, most recently as the Plant Manager at Prairie Creek Generating Station in Cedar Rapids, Iowa.

“I’m excited and honored to have the opportunity to build upon the standard established by Kathy Lipp.” said Doug Kopp. “At Alliant Energy, environmental responsibility is exhibited through the environmental stewardship of our company and our employees. I am intent upon seeing that commitment remain as we work to deliver cost-effective energy to our customers in an environmentally responsible manner.”

Kopp will begin in his new role on January 1, 2011.

Alliant Energy Corporation is an energy-services provider with subsidiaries serving approximately 1 million electric and over 412,000 natural gas customers. Providing its customers in the Midwest with regulated electric and natural gas service is the company’s primary focus. 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 http://www.alliantenergy.com.