Two companies that want to store Cook Inlet natural gas production so it can be used by consumers during the winter said Wednesday they have applied for a state certificate for the project. Semco Energy Inc. and MidAmerican Energy Holdings Co. have formed a joint venture named Cook Inlet Natural Gas Storage Alaska to complete the enterprise. The joint venture applied with the Regulatory Commission of Alaska to own and operate an underground natural gas storage system, they said.

They hope to start storing gas starting in the summer of 2012. Natural gas is used to heat homes and businesses, and to generate electricity in the region.

Semco is a Michigan-based sister company of Enstar Natural Gas Co., the Anchorage business that pipes gas to buildings throughout the area. Enstar is envisioned as the primary user of the stored gas, with the rest taken by Chugach Electric Association and Anchorage's Municipal Light & Power utility, Cook Inlet Natural Gas said.

MidAmerican is an Iowa-based provider of electric and natural gas service worldwide.