The Madison-based utility has more than 467,000 customers in Wisconsin. The company's service area includes parts of 10 counties in Northeast Wisconsin.
Alliant is asking the Public Service Commission for permission to reduce natural gas rates by a total of $5 million in 2015, then freeze them in 2016. The electric rate freeze would stay in effect through 2016. On top of the base rates, Alliant would still adjust bills for fuel costs.
The proposal makes note of improvements made to Columbia Energy Center and Edgewater Generating Station, as well as investments in the electric and natural gas delivery systems.