PG&E adds to renewable portfolio

San Joaquin Solar LLC, a subsidiary of Martifer Renewables (itself a subsidiary of Martifer Group), plans to spend $450 million to build two plants near Coalinga that will both utilize hybrid solar thermal and biofuel technology.

The projects combine solar thermal trough technology from Luz, the predecessor company of Oakland's BrightSource Energy, and steam turbines powered by biomass fuel to produce renewable electricity. Incorporating biofuel to power the steam turbines will allow the plants to generate power around the clock. Each plant has capacity to generate 53.4 megawatts of electricity.

The plants are expected to begin operation in 2011.

The contracts stem from PG&E's 2007 request for proposals for renewable energy projects to fulfill the state's aggressive renewable portfolio standard, which requires the state's investor-owned utilities to provide 20 percent of their electrical generating resources from renewable power by 2010. California's renewables standard is the most aggressive in the country.

This latest contracts bring PG&E's renewable energy portfolio to more than 20 percent of its future deliverable energy, but many of the projects it has lined up are not yet on line. For this year, PG&E expects to have 14 percent of its energy delivered from renewable sources.

Since 2002 PG&E, a subsidiary of PG&E Corp. in San Francisco, has signed contracts for more than 2,500 megawatts of renewable power. One megwatt provides enough electricity to power about 650 homes.