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.
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.
While Google has made a significant dent in its power requirements with renewable energy, green power projects such as the Grand River Dam Authority windmill farm cost more than brown, or polluting, energy resources.
"In places where we're procuring renewable energy through a utility ... we're paying a slight premium for that power, but it's worth it to the company because we've determined that small premium we pay is financially reasonable," Demasi said. "It's tough to procure renewable energy at equal to or less than what you can buy power off the grid," he continued. "So you've got to have a corporate appetite for that premium. The founders and leaders of the company believe we should do the right thing for the environment. That's definitely a clear mandate."
By pumping money into renewable energy resources, Google also hopes to drive up the economies of scale in order to eventually push prices below that of brown energy resources, Demasi said.
According to the U.S. Energy Information Administration, utility-scale wind projects cost about $2 per watt to install, and solar projects are about $3 per watt. Using those figures, a 100-megawatt wind project would cost about $200 million; a similar solar facility would cost about $300 million.