Google plans to build a solar-powered electricity system at its headquarters that will be rank the Mountain View, Calif., complex as the largest solar-powered office complex in the United States, and possibly the world. The previous corporate office record was held by FedEx's operating hub at Oakland International Airport.

Google's rooftop solar-powered generation system will generate 1.6 megawatts of electricity, enough to power about 1,000 California homes. The solar power will provide enough electricity for about one-third of the 1-million-square-foot campus, excluding power consumed by data centers.

This is not Google's first foray into renewable energy sources. Earlier this year Google's for-profit philanthropy organization, Google.org, announced that it was developing a hybrid car engine that runs on ethanol, electricity and gasoline.

Google rival Microsoft is also involved with solar power. Microsoft commemorated Earth Day this year by flipping the switch on its own solar power generator at its office in Mountain View. That installation generates 480 kilowatts at peak capacity.

The world's largest solar power installation is a 12-megawatt facility in Arnstein, Germany, according to PVResources. The largest U.S. facility generates 4.6 megawatts and is located in Tucson, Ariz.