Granite is the largest commercial-scale wind farm in New Hampshire. The project, which was originally developed by Noble Environmental Power, was sold to Brookfield Renewable Power in December.
Noble ordered 33 Vestas V90 3MW turbines for the site at the beginning of 2010. The majority of the power from the project will be sold to Central Vermont Public Service and Green Mountain Power.
According to the latest Windpower Monthly Windicator, New Hampshire has an installed capacity of 25MW.
Speaking about the guarantee, DOE secretary Steven Chu said: "This Administration is creating clean energy jobs, in New Hampshire and in countless states across the country, which will help the US to recapture the lead when it comes to the deployment of renewable energy."