MidAmerican Energy is still mulling if, when, and where to build a new power-generating plant in Iowa. In April as Iowa legislators were considering a bill which would have deregulated electric utilities, MidAmerican officials leaked the idea of building a new power plant. The bill died, and MidAmerican spokesman Kevin Waetke says the plans for new generation were put on hold.MidAmerican has power-generating stations in Sioux City, Council Bluffs, Ottumwa, Muscatine and the Quad Cities.CalEnergy Generation, a unit of MidAmerican, announced last week it would build a power plant in Wisconsin, but Waetke says that plant is to provide power for east-central Wisconsin.