Google April 11 said it put $168 million into a solar energy power plant BrightSource Energy is building in California's Mojave Desert, easily the search engine's largest investment in clean energy to date.
Clean energy-also known as sustainable, renewable and green energy-includes hydroelectricity, solar energy, wind energy, wave power, geothermal energy, bioenergy and tidal power.
Brightsource's Ivanpah Solar Electric Generating System, which will also be financed by NRG and with clean energy technology loans from the U.S. Department of Energy, certainly falls in the solar energy category.
The plant employs a field of 173,000 heliostats, each with two mirrors, to redirect the sun's rays onto a solar receiver on top of a tower.
The solar receiver generates hot (up to 1,000 degrees Fahrenheit), high-pressure steam, which in turn spins a turbine and generator to make electricity.
When its construction is complete in 2013, the Ivanpah Power Tower will be roughly 450 feet tall and will generate 392 gross megawatts of clean solar energy.
Rick Needham, director of green business operations for Google, said this is the equivalent of taking more than 90,000 cars off the road over the projected 25-year lifetime of the facility.
"We're excited about Ivanpah because our investment will help deploy a compelling solar energy technology that provides reliable clean energy, with the potential to significantly reduce costs on future projects," Needham explained.
Google, a massive consumer of energy to power the thousands of computers that fuel its search and Web services, has pumped more than $250 million into clean energy. Google's investments to date have been either in wind and/or tidal energy.
Google last October invested 37.5 percent into the Atlantic Wind Connection backbone, which is meant to power offshore windmills by connecting undersea cables along the Atlantic coastline.
Google last May pumped $38.8 million into two NextEra wind farms in North Dakota, and late in July agreed to buy 114 megawatts of clean energy from one of those wind farms at a predetermined rate for 20 years.
The company gained the right to buy and sell power on regulated wholesale markets from the Federal Energy Regulatory Commission in February 2010.
Google, which earned $29 billion last year from advertising, is just one of many clean energy contributors.
Bloomberg New Energy Finance said nearly $243 billion was invested in 2010 in wind farms, solar power, electric cars and other alternative technologies worldwide, representing a 30 percent increase from 2009.