Edison International received state approval on Thursday to go ahead with a contract with a local solar energy startup for new solar power plants in Kern County.

The California Public Utilities Commission approved the 20-year contract between Rosemead-based Edison and eSolar Inc., a Pasadena-based renewable energy start-up financed by Google.org, Idealab and Oak Investment Partners. The contract calls for Edison to purchase up to 245 megawatts of electricity from solar power plants built by eSolar in the northern Antelope Valley.

The power plants will use mirrors to focus sunlight on towers containing water. The water is heated and turned into steam, which powers turbines and generates electricity.

The first of these solar power plants is set to come online in early 2012.