Google Inc. plans a solar-powered electricity system at its Silicon Valley headquarters that will rank as the largest U.S. solar-powered corporate office complex, the company recently announced.

The firm is set to begin building a rooftop solar-powered generation system at its Mountain View, Calif., headquarters capable of generating 1.6 MW of electricity, enough to power 1,000 California homes.

"This is the largest customer-owned solar electric system at a corporate site," said Noah Kaye, director of public affairs at the Solar Energy Industries Association, an industry group based in Washington, D.C.

A Google executive said the company will rely on solar power to supply nearly a third of the electricity consumed by office workers at its roughly one-million-square-foot headquarters. This excludes power consumed by data centers that power many of Google's Web services worldwide, he said.