IOWA GENERATING STATION TO USE SWITCHGRASS AS FUEL.

Interstate Power and Light Company (IPL), Cedar Rapids, Iowa, a subsidiary of Alliant Energy Corporation (NYSE:LNT has announced a partnership with Prairie Lands Bio-Products, Inc. (Prairie Lands) to assess ways to create a commercially viable market for switchgrass or other similar agriculturally based products to serve as a fuel source for up to 10 percent of the power for the proposed 630 megawatt Sutherland Generating Station Unit 4 in Marshalltown, Iowa.

As part of the assessment, Prairie Lands is evaluating the potential environmental, economic and agricultural benefits of switchgrass or other similar agricultural products. Prairie Lands Bio-Products, Inc. is also identifying cost-effective and efficient methods to collect, aggregate, process, and deliver the products to the power plant.

"We are excited to partner with IPL and assist in developing a fuel supply for this state of the art facility," said Bill Belden, Manager of Prairie Lands. "The Prairie Lands Board of Directors is gratified that IPL recognizes our contributions to the Chariton Valley Biomass Project and has the confidence in our ability to develop and deliver biomass fuel."

Prairie Lands' assessment will build upon the successful switchgrass test burn demonstrations conducted during the Chariton Valley Biomass Project (CVBP) in 2006. The CVBP, funded by IPL and the United States Department of Energy, sought to investigate and demonstrate the technical feasibility, environmental benefits and potential business viability of growing switchgrass to replace a portion of the coal fuel supply at the Ottumwa Generating Station in Chillicothe, Iowa.

"We are pleased to partner with Prairie Lands on the development of a renewables market that can power Sutherland Generating Station Unit 4," states Tom Aller, president of IPL. "The proposed power plant's hybrid technology creates economic development opportunities, jobs and enables our company to permanently reduce greenhouse gas emissions. Iowa continues to grow its renewable energy economy and the use of renewables as a fuel source in the proposed power plant benefits our environment and economy. We look forward to working with Prairie Lands Bio-Products in continuing to position Iowa as a leader in renewable energy."

Prairie Lands expects to provide IPL with a study and assessment of methods to develop a commercially viable market.

The 630 megawatt facility expects to be operational in 2013 and would provide enough energy to power approximately 472,500 homes and businesses. The facility's design consists of a hybrid technology, which allows the facility to utilize switch grass, corn stalks or other similar agriculturally based products for up to 10 percent of its fuel source. As a result, IPL expects to reduce the amount of coal burned at the facility. An additional 19 megawatt equivalent of steam cogeneration will be available for use by nearby industries.

About Alliant Energy

Alliant Energy is an energy-services provider with subsidiaries serving approximately 1 million electric and 400,000 natural gas customers. Providing its customers in the Midwest with regulated electric and natural gas service is the company's primary focus. Interstate Power and Light, the company's Iowa utility subsidiary headquartered in Cedar Rapids, Iowa, serves approximately 530,000 electric and 235,000 natural gas customers. Alliant Energy is a Fortune 1000 company traded on the New York Stock Exchange under the symbol LNT.

For more information, visit http://www.alliantenergy.com or call 319/786-4171.