Sep. 15--Wisconsin Power & Light Co. plans to spend as much as $175 million to build a wind-power project in Fond du Lac County to beef up the amount of electricity it produces with wind turbines.

The Cedar Ridge Wind Farm in the Towns of Empire and Eden would consist of about 40 wind turbines generating enough power to meet the needs of roughly 20,000 homes.

On Thursday, the utility filed an application with state regulators seeking a guaranteed rate of return over 20 years, under the provisions of a state law that passed last year.

Wisconsin Power & Light Co., a subsidiary of Alliant Energy Corp., produces about 3% of its electricity from wind turbines, spokeswoman Erin Dammen said.

That would jump to as much as 5.5% after the proposed wind-power project begins operating, if it's approved, she said.

A state law passed last year requires that 10% of the state's electricity be produced by renewable sources of power, whether wind turbines, solar panels, waste-to-energy systems or hydroelectric plants, by 2015.

The utility wants a 12.9% return on its investment, it said in a filing with the state Public Service Commission.

That's similar to the 12.7% return authorized by state regulators for Milwaukee-based Wisconsin Energy Corp. for its more than $2 billion investment to build new coal-fired power plants in Oak Creek.

The head of an electric customer group that regularly weighs in at the state Public Service Commission indicated Thursday that the profit Wisconsin Power & Light seeks to make on its wind-project investment seemed "quite high."

"Any way you slice it, we think they'll probably need to crank down on how much that's going to cost," said Todd Stuart, executive director of the Wisconsin Industrial Energy Group, which represents more than 30 manufacturers that use significant amounts of energy in their production processes.

In a filing Thursday, a consultant hired by the utility said he concluded the 12.9% return was appropriate given the risks associated with building wind-energy projects and it would provide both price stability for customers and earnings stability for Alliant.

For more information, see www.alliantenergy.com/cedarridge To see how a wind turbine works, see: www1.eere.energy.gov/windandhy dro/ wind_animation.html