El Solution, the systems-integration arm of Energy Innovations Inc., switched on the historic solar electricity system it built with a total capacity of 1.6 megawatts.

Officials estimate the energy capacity is enough to supply 1,000 average California homes. The Google system is also now the largest solar installation on any corporate campus in the United States.

The project began in October 2006 and was completed on schedule and on budget using 9,212 solar panels provided by Sharp Electronics.

The majority of the solar panels were installed on the rooftops of the Googleplex, which include multiple architectures and required the use of four different mounting systems. The remaining panels were placed on newly constructed carports in existing Google parking lots, allowing for additional capacity and providing shaded parking and a visible example of Google's commitment to clean energy.

"It has been a distinct pleasure to work with Google to design and construct this historic project," said Andrew Beebe, president of EI Solutions. "Google's commitment to reducing their environmental impact through solar on such a large scale should be applauded."