Blue Sky Green Field

Blue Sky Green Field


Blue Sky Green Field is located in the towns of Calumet and Marshfield in northeastern Fond du Lac County, east of Lake Winnebago.

Type of plant

Wind turbine

Initial cost

Approximately $300 million


88 turbines

Year in service


Net generating capacity

1.65 megawatts each – 145 megawatts total

Turbine manufacturer

Vestas Wind Systems

Turbine design

Vestas V82 is a horizontal axis, pitch-regulated, upwind turbine.

Total weight

Tower and turbine: 204 tons

Rotor design

Three blades constructed of a fiberglass-reinforced epoxy coating around a wood/carbon fiber frame.

Rotor diameter

82 meters (269 feet)

Rotor speed

14.4 rpm


An asynchronous 6-pole, 3-phase induction generator with wound rotor and full-load reactive power compensation.

Generator nominal voltage

600 volts, 3-phase

Integrated lightning protection

Protection system includes lightning receptors and conductors in the rotor blades, lightning arrestors, deep earth grounding and shielding.

Control system

A microprocessor controls all turbine functions.

Tower dimensions

Hub height: 262 feet
Weight: 140 tons
Base diameter: 13.8 feet
Rated power output: 1.65 MW @ 30 mph

Cut-in wind speed

8 mph

Cut-out wind speed

54 mph

Extreme gust wind speed

133 mph

Updated: December 2012