Onsite solar power arrays are becoming more common and visible, like this one at the Denver International Airport that takes up seven acres and provides 2 million watts of power
A greener Google
In 2011, the EPA awarded Google the Green Power Partner of the year award.
Google has pledged to reduce its carbon footprint to zero through energy efficiency and by purchasing carbon-free renewable electricity to power its data centers and corporate facilities.
Currently, a third of Google's energy consumption comes from renewable energy -- 13% from utility companies and the remaining 20% from wind and solar facilities owned by Google or a third party owns.
In 2007, Google constructed a 1.7-megawatt solar farm for its central facilities in Mountain View, Calif. The cost of that project, which has not been disclosed, was expected to produce return on investment (ROI) within seven years through cost savings. It's now on target to beat that projection and see ROI this year, according to Gary Demasi, Google's director of Global Infrastructure.
From this year forward, the solar power facility will continue to produce about 3 million kilowatt hours of power per year, saving the company in energy costs while reducing its carbon footprint.
In 2011, Google signed two 20-year contracts to purchase all the power from wind farms in Iowa and Oklahoma for two of its data centers in those states. The first contract was for 114 megawatts of wind generation from NextEra's Story County II facility in Iowa; the second was for 100.8 megawatts of wind generation from NextEra's Minco II facility in Oklahoma.
NextEra wind farm in Oklahoma (source: NextEra)
Last year, Google signed a separate wind power purchase agreement with the Grand River Dam Authority to power the company's Mayes County, Okla. data center with 48 megawatts of wind energy from the Canadian Hills Wind project.
"We've also done some methane capture projects on some landfills in the U.S., thereby reducing the amount of carbon released into the atmosphere," Demasi said.
Large-scale data centers and corporate facilities can use tens of millions of watts of electricity and they require a steady, reliable power source. While both wind and solar are intermittent power sources, solar has an advantage over windmills -- even if wind power is steadier.
"The nice thing with solar is it produces energy when your data centers are at peak power rates, during the middle of the day when its super hot inside," Demasi said.