Renewable energy will now be required to be stored in California so it can be used in off-hours. The most common method is pumped-hydro, with batteries an obvious choice too. With pumped hydro, water is pumped uphill to a holding area. When power is needed, the water is released and used to create energy.
California also just increased its renewable energy goal to 12% by 2012 and 33% by 2020.