Rosiere Wind Farm

In 1999, MGE built and today operates a wind farm in the townships of Lincoln and Red River in northwest Kewaunee County, Wisconsin. Each of the 17 turbines can produce 660 kW to provide renewable, Wisconsin-based electricity.

Annual energy production

  • 11.2 megawatts (MW) annually
  • Rated power output is 660 kW at 33 mph (optimal operating wind speed)


Average wind speed is 13 to 14 mph (at 110 feet aboveground).

  • Cut-in speed: 9 mph
  • Cut-out speed: 56 mph

Wind blows predominantly from a west (from the northwest through the southwest) direction.


Manufactured by Beaird Industries, Shreveport, LA, the tubular steel towers are assembled in three sections with internal safety ladder and nacelle access.

  • Weight: 73.5 tons
  • Height: 213 feet
  • Diameter: 12 ft at the base and 6.5 ft' at the top


Each horizontal axis, up-wind turbine weighs 20 tons (complete nacelle without rotor) and has an expected life of 30 years. They are Vestas V47-660 kW pitch-regulated wind turbines withOptiSlipandOptiTip.


Three 77' blades (154' rotor diameter) constructed of fiberglass reinforced epoxy and other composite materials.

Yaw drive system

Electric motor driven with wind direction sensor and cable dewinding control. Braking accomplished through friction pads.

Gear box

High-performance planetary/helical.


The nominal voltage is 690 VAC for the single-speed, variable slip, asynchronous, four-pole induction generator.

Foundation design

Concrete pier 15' to 30' deep with 14' external diameter. Anchor bolts attach tower to the foundation.

Control system

Computer-controlled, automatic, independent operation and remote supervision from operations center in Madison. Microprocessor-based monitoring of yaw, hydraulic, ambient conditions, rotation, generator, pitch system, grid, power factor correction, thyristors (generator cut-in) and remote monitoring.

Integrated lightning protection

System consists of lightning receptor points, conductors, grounding system and surge protection for every subsystem.


  • 30.5 acres are leased within seven parcels totaling 60.3 acres
  • Within the 30.5 acres, 7.4 are used for the foundations, transformers and access roads


The grid interconnection is 690-volt cables to 750-kilovolt ampere (kVA) step-up transformers to 24.9-kV collection voltage underground to overhead to 138-kV overhead transmission line.

The brake system consists of a primary and secondary brake.

  • Primary: rotor-pitching mechanism (feathers blades)
  • Secondary: hydraulic disc brake

The total cost of the project was $14.5 million. The noise level is 47 decibels at 800' downwind.