San Francisco’s Pacific Gas & Electric (NYSE: PCG) has announced plans to add 106.8 MW of solar thermal-biofuel hybrid power to its renewable energy portfolio.

Two new contracts with San Joaquin Solar, a subsidiary of Portuguese-owned Martifer Renewable Electricity (ELI: MAR), are renewable hybrid contracts which are to combine Luz solar thermal technology and steam turbines powered by biomass fuel to produce solar-biofuel electricity, said PG&E.

According to the Northern California power utility, the incorporation of biofuel increases the overall production of renewable power by allowing for constant clean energy production.

Each hybrid project will require 250,000 tons of biofuel annually, to be supplied from a combination of locally-produced agricultural wastes, green wastes and livestock manure, said PG&E.

Located near Coalinga, California, the solar-biofuel projects are expected to deliver a total of 700 gigawatt hours annually of renewable electricity to PG&E customers.

The financial details of the contracts were not disclosed.

Southern California's Southern California Edison (SCE), a division of Edison International (NYSE: EIX), recently signed a deal with eSolar to deliver 245 MW of solar thermal to its customers (see SCE brings more solar thermal to California).

As part of California’s renewable energy requirements, investor-owned utilities such as PG&E are to increase the share of eligible renewable generating resources in its electric power portfolio to 20 percent by 2010.

According to the company, it currently has 2,500 MW in renewable power contracts. The company said it expects to have 14 percent of its energy delivered from renewable sources in 2008.

However, the Coalinga projects aren’t expected to begin operation until 2011.