California is ground zero for what Southern California Edison (SCE) and BrightSource Energy say is the “world’s largest solar deal.”

Inked today, the contract between the two companies calls for the development of seven solar plants with a total capacity of 1,300 megawatts — enough to power almost 845,000 homes.

If the agreement wins the approval of the California Public Utilities Commission, the first solar plant — a 100-megawatt facility in Ivanpah, California — could be up and running by 2013.

Under the proposal, BrightSource will install its proprietary Luz Power Tower 550 (LPT 550) solar-thermal energy system at each solar plant. The system uses thousands of small mirrors, or heliostats, to reflect light onto a tower-top boiler that produces steam. The steam then drives a conventional turbine to produce electricity.

All seven solar plants, once they go into operation, would yield an annual carbon emissions reduction of more than 2 million tonnes — as much as is generated by 335,000-plus cars.

• Company uses solar thermal power for ‘greener’ kidney dialysis
• Solar firm BrightSource Energy expands management team