As part of Google's quest to power its operations with 100% renewable energy, the company has agreed to purchase the entire output of the 240 MW Happy Hereford wind farm outside of Amarillo, Texas. This agreement represents Google's fifth long-term agreement as the company has now contracted for more than 570 MW of wind energy, which is enough energy to power approximately 170,000 U.S. households.

The Happy Hereford wind farm, which is expected to start producing energy in late 2014, is being developed by Chermac Energy, a small, Native American-owned company based in Oklahoma. The wind farm will provide energy to the Southwest Power Pool (SPP), the regional grid that serves Google's Mayes County, Okla. data center.

Due to the current structure of the market, Google can't consume the renewable energy produced by the wind farm directly, but the impact on the company's overall carbon footprint and the amount of renewable energy on the grid is the same as if it could consume it. After purchasing the renewable energy, Google retire the renewable energy credits (RECs) and sell the energy itself to the wholesale market. Google will apply any additional RECs produced under this agreement to reduce its carbon footprint elsewhere.