For most of the year, California’s quest to rid itself of fossil fuels seems on track: Electric cars populate highways while energy from wind, solar and water provides much of the power for homes and businesses. Then it gets hot, and everyone in the nation’s most populous state turns on their air conditioners at the same time. That’s when California has come close to running out of power in recent years, especially in the early evenings when electricity from solar is not as abundant. … Another area ripe for new energy development is the Salton Sea, a large saltwater lake in Southern California that has been slowly drying up. Beneath the surface of the lakebed, heat from the Earth warms underground water. Geothermal power plants use steam from this water to spin turbines that generate electricity.