MidAmerican Energy Co. said it plans to file two adjustment clauses with the Iowa Utilities Board in February that would raise electrical rates for its customers by an average of 3 to 4 percent next year.

Increases in regulatory and production costs are primary drivers behind the request, which would be the first increase since 1995, said Tina Potthoff, a company spokeswoman. “We have a coal contract that is coming up for renewal next year; that plays a major part in this request,” Potthoff said. 

Fifty-two percent of the Des Moines-based utility’s electrical generating capacity is fueled by coal. Potthoff said MidAmerican’s environmental compliance costs in 2010 exceeded $425 million.

The increases, if approved, would go into effect in March. The utility serves nearly 1,800 industrial electricity customers and more than 50,000 commercial users in Iowa, in addition to more a half-million residential accounts.