The firm said it has commitments to buy 2.6GW of wind and solar power – enough to support its offices and data centres globally, the firm said.
In a post on the company's website, Google senior vice president of technical infrastructure, Urs Holzle, said: "Over the last six years, the cost of wind and solar came down 60% and 80%, respectively, proving that renewables are increasingly becoming the lowest cost option.
"Electricity costs are one of the largest components of our operating expenses at our data centres, and having a long-term stable cost of renewable power provides protection against price swings in energy," Holzle added.
Google said it buys power from 20 renewable energy projects in the US, Chile and Sweden. The firm said it was looking to continue buying renewable electricity from more sources.
Its first wind power deal was agreed in 2010 to buy the power from the 114MW Story County II project in Iowa, developed by NextEra Energy Resources.