The Happy Hereford wind farm, which is being developed by Chermac Energy, is scheduled to be operational in late 2014.

The power generated from the plant will be supplied to the Southwest Power Pool (SPP), the regional grid that serves Google’s data centre in Mayes County, Oklahoma.

According to Google, the agreement represents its fifth long-term agreement and the company has now contracted for more than 570MW of wind energy, which is enough energy to power about 170,000 US households.

In 2012, Google signed an agreement with its utility partner in Oklahoma, GRDA, to supply 48MW of wind energy to its Oklahoma data centre from the Canadian Hills Wind Project. Earlier in 2013, Google began working with Duke Energy to develop a new renewable energy tariff (PDF) in North Carolina.