Central Iowa Power Cooperative and Corn Belt Power Sign Letters of Intent to Evaluate Partnership in New Marshalltown Power Plant

Ownership share and potential additional partners will be determined later this year

Interstate Power and Light Co. (IPL), a subsidiary of Alliant Energy Corporation (NYSE: LNT) announced that letters of intent have been signed by Corn Belt Power Cooperative of Humboldt, Iowa and Central Iowa Power Cooperative (CIPCO) of Cedar Rapids. Both organizations have agreed to evaluate this opportunity and negotiate toward a definitive ownership interest in IPL’s planned 600 MW high-efficiency super-critical pulverized coal generating facility. The facility is planned for a site adjoining the existing Sutherland Generating Station in Marshalltown, Iowa.

The letters of intent do not detail the ownership stake either organization will have in the facility. Total ownership stakes are expected to be negotiated and announced later this year. Any additional ownership partners will also be announced later this year. IPL previously announced plans to own at least 250 MW of the new generating unit to meet the growing demands of its utility customers.

“We’re extremely pleased that CIPCO and Corn Belt Power are considering a partnership with us,” said Tom Aller, president of IPL. “We want partners focused on meeting our state’s future energy needs. Both of these organizations share our commitment to meet Iowa’s growing demand for electricity through construction of a highly efficient, modern generating facility. IPL, CIPCO and Corn Belt Power serve customers in 94 of Iowa’s 99 counties, so their partnership in this plant could provide benefits to every corner of Iowa.”

“The new plant would be an attribute to the CIPCO system and help support the increased need for more energy to bolster the robust economic growth throughout our member cooperative service areas,” said CIPCO executive vice president and chief executive officer, Dennis Murdock. “The production facility, which is located in the heart of our members’ 58-county service territory, would provide a dependable energy source positioning CIPCO to meet the around-the-clock needs of our member-owners.”

“A jointly owned power plant allows a company of our size to benefit from the economies of scale achieved by working with others, similar to how we have partnered to build and operate other power plants,” says Kenneth Kuyper, executive vice president and general manager, Corn Belt Power. “The timing of this project, along with Corn Belt Power’s announced addition of more wind energy, helps us to serve the growing rural economy as the commercial operation date matches our member systems’ needs.”

The high-efficiency boiler system chosen for this facility will burn less coal to produce each megawatt of power than existing power plants. The plant will include the Best Available Control Technology to further reduce air emissions. Those controls will ensure the plant can meet stringent air emission standards, and will reduce particulate, NOx, SO2 and mercury emissions as regulated by the Iowa Department of Natural Resources and federal regulators.

Plans call for the boiler to be designed to burn biomass fuels, such as switchgrass. Provisions are also being made to allow for co-generation at a nearby economic development site.

Design work on the new plant continues and permitting and regulatory approval efforts are underway. IPL expects to file the regulatory applications with the Iowa Utilities Board beginning in mid 2007. Once the necessary regulatory approvals are received, groundbreaking could begin in late 2008. IPL expects the plant to begin commercial operation in 2013. In addition to the power plant, IPL is also planning to add 100 MW of company-owned wind generation in Iowa and Minnesota.