NRG Energy has signed an agreement with eSolar to develop solar power plants with a total generation capacity of up to 500 megawatts (MW) at sites in California and the Southwest. The first plant is expected to begin producing electricity as early as 2011.

At closing, NRG will invest approximately US $10 million for equity and associated development rights for three projects on sites in south central California and the Southwest U.S. The company will also sign a portfolio of power purchase agreements (PPAs) to develop, build, own and operate up to 11 eSolar modular solar generating units at these sites.

“This is NRG’s first venture into solar power and it brings an exceptionally important component to the low- and no-carbon focus of our Repowering NRG program,” said Michael Liebelson, chief development officer of Low Carbon Technology for NRG Energy. “By coupling NRG’s construction capabilities and regional operating expertise with eSolar’s innovative CSP technology, we can advance NRG’s renewable energy portfolio while helping to accelerate development of these important projects on a commercial scale.”

eSolar is currently completing its first commercial demonstration CSP plant in Southern California. The facility will be the first fully functioning solar thermal power tower plant built in the United States.