SolarReserve and utility PG&E have signed a contract, under which PG&E will buy power from solar power plant. This California utility will buy 150 megawatt of power.

California will attain one- third of its power from renewable resources, but the major difficulty that the company is facing now is to figure out how to store energy for the days when there will be no sunlight or it is overcast.

SolarReserve has a license to use the molten salt solar power technology project and it utilizes mirrors to focus sunlight to heat molten salt, which heats water for a steam generator to produce electricity. The molten salt technology also can store the energy when sunlight is not available.

The utility said that the project will be ready in 2013 and will be able to generate electricity for 60,000 homes.

PG&E Corp.’s shares closed down 0.6 percent at $44.81 on Tuesday on the New York Stock Exchange.