The group, however, rejected part of the bid that would have added 1 percent to Westar's return for developing wind energy, the Wichita Eagle reported Friday.

Westar said it wanted the premium to compensate for the increased risk of developing wind power compared to more traditional fossil fuels, the paper reported.

The project, which is still pending, would add about 300 megawatts of wind power over the next 20 years. The plans would provide enough electricity to power 90,000 homes and is projected to cost about $830 million.

Westar officials said they estimated the plan would raise the average customer's bill by $2.25 a month.

The commissioners ruled against Westar Thursday, saying the return would cost ratepayers more than $47 million over the next 20 years.