Blue Sky Green Field Wind Energy Center

Blue Sky Green Field Wind Energy Center

The Blue Sky Green Field Wind Energy Center, located in the towns of Calumet and Marshfield in northeast Fond du Lac County, is designed to generate 145 megawatts (MW) of electricity, and is capable of powering approximately 36,000 average residential homes. The site consists of 88 wind turbines.

Construction of the project began in June 2007. The project was built largely with the talents and products of Wisconsin companies and skilled labor. Collectively, more than 400,000 labor hours were invested in completing the project.

On May 19, 2008, Blue Sky Green Field was placed into commercial operation. The turbines will generate more than 328 million emission-free kilowatt-hours annually.

Site attributes

The Blue Sky Green Field Wind Energy Center is located geologically, along the Niagara Escarpment in Fond du Lac County. The Niagara Escarpment is the steep sloped edge of a bedrock ridge known as a cuesta that runs from southeastern Wisconsin through the Door Peninsula, Northern Michigan, and Ontario, Canada into New York. The predominant bedrock type is dolomite, formed by the deposition of marine sediments over 400 million years ago during the Silurian Period of the Paleozoic Age. The escarpment itself was formed over millions of years through differential erosion of the cap of erosion resistant dolomite and the more easily eroded underlying shale rocks. As the relatively soft shale erodes, it undercuts the resistant dolomite forming the cliffs and bluffs of the escarpment line in Wisconsin.

Turbine equipment

We Energies purchased 88 wind turbines from Vestas Wind Systems. Each Vestas V82 turbine is capable of producing 1.65 MW of electricity.



Electric Capacity

1.65 MW

Hub Height

262 ft

Blade Length

134 ft

Tip Height

397 ft

Operational RPMs


Cut in wind speed (mph)


Rated wind speed (mph)


Cut out wind speed (mph)


Weight of rotor (tons)


Weight of nacelle w/o rotor (tons)


Weight of tower (tons)


Wind farm map


Blue Sky Green Field video Learn more about wind energy and development of Blue Sky Green Field Wind Energy Center.