July 2014 - Microsoft Corporation plans to purchase wind power from a new 175-megawatt (MW) wind farm through a 20-year power purchase agreement (PPA) with EDF Renewable Energy, a U.S. developer and subsidiary of Electricite de France SA, to offset its power needs of its Chicago-area datacenter. As of July 2014, the Pilot Hill Wind Project was under construction at the border of Illinois’s Kankakee and Iroquois counties, and is expected to begin operating in 2015. The wind farm will have enough installed capacity to supply electricity to 70,000 homes.

Press Release - EDF Renewable Energy Acquires 175 MW Wind Project with a Power Purchase Agreement with Microsoft

News Article - Microsoft Announces New Wind Project To Power Data Center

Additional Information - Microsoft Funds Green Power Through Internal Carbon Tax (November 2013)

Additional Information - Project Detail - Pilot Hill