The deal includes 114 megawatts of wind power from the NextEra Energy Resources facility in Story County, Iowa, at a predetermined rate.
The power is enough to supply several energy centers for Google.
The contract will also, according to the post, allow the wind farm enough financial security to build some more farms, helping to expand renewable energies. Further, taking 114 megawatts of wind power off the market will also help to reduce supply, encouraging other developers to build more to meet demand.
The company said in 2007 that they would go carbon neutral. Since then, they have built efficient data centers, have worked to powered their headquarters with solar power, and purchased carbon offsets. Google notes that Incorporating such a large amount of wind power into our portfolio is tricky"; read more about the deal here.