Google has signed a 20-year agreement to buy energy from a wind farm in Iowa, giving it access to enough renewable energy to supply several of its data centers, the company said on Tuesday.
The deal provides Google with access to 114 megawatts of wind power at a fixed price over the 20-year period, said Urs Hoelzle, Google senior vice president for operations, in a company blog post.
The predetermined rate will help shield Google from fluctuations in energy prices, while the long-term agreement should encourage investment in further renewable energy plants, he said.
"This is a case where buying green makes business sense," Hoelzle said. He didn't disclose how much Google will be paying for the energy, however.
In May, Google invested US$38.8 million in two North Dakota wind farms developed by NextEra Energy Resources. The deal it signed Tuesday is with a facility owned by the same company.
NextEra claims to operate the largest number of wind turbines in North America, with 9,000 in operation, providing 7,600 megawatts of total power. It will start supplying the wind power to Google on July 30.
"By contracting to purchase so much energy for so long, we're giving the developer of the wind farm financial certainty to build additional clean energy projects," Hoelzle said in the post. "The inability of renewable energy developers to obtain financing has been a significant inhibitor to the expansion of renewable energy."
Incorporating the wind power into Google's business was "tricky," Hoelzle said. The U.S. has strict regulations that control how companies can buy and sell energy.
The purchase was made through Google Energy, a subsidiary the company set up in December and which was granted federal approval to buy and sell energy on the wholesale market. Google can't use the energy directly and must first sell it back to the grid on the local spot market, Hoelzle said.
Online giants like Facebook, Yahoo and Google have been coming under scrutiny lately for the energy used by their giant data centers. In particular, Greenpeace has taken aim at companies that build new data centers where the source of power is coal-fired plants.