Google has this week become the latest IT giant to respond to criticism of the environmental footprint of its data centres with a major deal to purchase wind energy for one its largest US facilities.

The company announced that it has signed an agreement with the Grand River Dam Authority (GRDA) that will see it supply 48MW of wind energy to Google’s Oklahoma data centre from the nearby Canadian Hills Wind Project when it comes online later this year.

“We’ve been working with GRDA, our local utility, to procure additional renewable energy since we ‘plugged in’ our data center in 2011, and in February of 2012 GRDA approached us about purchasing power from Canadian Hills,” revealed director of global infrastructure at Google Gary Demasi on the company’s blog.

“In conjunction with the electricity GRDA already supplies Google to operate its data centre, Google will pay GRDA a premium to purchase renewable energy generated by Canadian Hills. This brings the total amount of renewable energy for which Google has contracted to over 260MW.”

He added that the deal was different to previous renewable energy supply contracts the company had signed, marking the first time it had purchased clean energy from a utility provider rather than a renewable energy developer.

He also revealed that the company was working closely with other utility suppliers to increase the level of renewables in its energy mix and was looking forward to “working with other suppliers to deliver clean energy to our data centres”.

The deal represents another boost to Google’s green credentials after the company announced back in 2007 that it had become “carbon neutral”. It has subsequently become a major player in the US renewables sector, investing in a host of renewable energy developers and taking steps to purchase power from specialist green energy suppliers.

The latest news was welcomed by Greenpeace, which issued a statement praising the Oklahoma contract and urging other data centre operators to secure similar deals.

“Google’s announcement today shows what the most forward-thinking, successful companies can accomplish when they are serious about powering their operations with clean energy,” said Greenpeace’s senior IT analyst Gary Cook. “Google faced a local grid mix of over 50 per cent coal power for its Oklahoma data centre. But, as a major electricity customer in the state, Google worked with its local utility to secure a new supply of renewable wind energy.”

He added that the move would increase pressure on other companies to follow suit, singling out Microsoft for criticism for failing to follow its recent commitment to achieve “carbon neutral” status with further announcements on improving its energy supply.

“Google’s announcement further sharpens the choice that people and businesses have when deciding what search, mail and cloud platforms to use,” he said. “While both Google and Microsoft have committed to being ‘carbon neutral’, unlike Google, Microsoft has yet to significantly invest in clean energy. Microsoft has instead continued to build data centres attached to dirty sources of electricity and sought to mask its dirty energy supply with carbon offsets and renewable energy credits.”