Southern California Edison and Stirling Energy Systems have signed a 20 year power purchase agreement that calls for the development of a 500 MW solar project just over100km northeast of Los Angeles.

The development, which will use Stirling dish technology, includes an option to expand the project to 850 MW potentially making it the world’s largest when complete.

Initially, Stirling plan to build a 1 MW test facility using 40 dish assemblies before a 20,000-dish array would be constructed near Victorville over a four-year period.

The Stirling dish technology converts thermal energy to electricity by using a mirror to focus sunlight on the receiver end of a Stirling engine, a technique that in tests has been shown to be twice as efficient as other solar technologies.