California utility Pacific Gas and Electric Company (PG&E) has signed an expanded agreement with solar thermal power company BrightSource Energy Inc for more than 1.3 GW.

These power purchase agreements, covering seven projects, supersede the agreements PG&E executed with BrightSource in April last year for up to 900 MW of solar thermal power. It is part of a push by PG&E to comply with a state requirement that at least 20 percent of its electricity supplies come from renewable sources by 2010.

The first of these solar power plants, sized at 110 MW and located in Ivanpah, Calif., is contracted to begin operation in 2012. The plans still require review and approval by the California Public Utilities Commission.

The utility, which has been in news for building and owning solar installations, estimates that BrightSource’s seven plants will be able to supply 530,000 homes.

In February this year, BrightSource also signed a deal with Southern California Edison to produce 1,300 megawatts of solar power over the next seven years.

Read more: PG&E, BrightSource, California Public Utilities Commission