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Bent Tree Wind Farm

Bent Tree Wind FarmThe Bent Tree Wind Farm is located near Albert Lea in Freeborn County, in southern Minnesota. It began commercial operation in February 2011.

Bent Tree consists of 122 wind turbines capable of producing up to 200 megawatts of emissions-free wind energy. That's enough energy to power approximately 50,000 homes.

The wind farm currently employs 25 people directly and indirectly through contracts. Many of those people live in nearby towns and cities bringing valuable economic activity to the area. Property taxes for the wind farm will be phased in over time which will bring even more benefit to the community.

The Bent Tree Wind Farm is owned and operated by Wisconsin Power and Light Company (WPL). The addition of Bent Tree allows WPL to meet and exceed Wisconsin’s existing Renewable Portfolio Standard. However, renewable energy above and beyond that standard may be sold for Renewable Energy Credits.

More pictures of the Bent Tree Wind Farm are available in our Wind Farm Photo Gallery.

Bent Tree Wind Farm Facts

  • The wind farm spans approximately 32,500 acres
  • There are 150 landowners participating in the project
  • There are 122 turbines, each is capable of producing approximately 1.65 megawatts of emissions-free energy, the equivalent of powering approximately 400 homes
  • Height of turbine from base to tip of blade pointing straight up = 397 feet
  • Distance from the ground to the hub = 262 feet
  • Each blade is approximately 131 feet long and weighs about 15,000 pounds
  • The total weight of each turbine including the tower, hub and blades is more than 480,000 pounds.
  • Power generation begins at 9 miles per hour with a maximum power generation of 27 miles per hour
  • The wind turbines can produce power approximately 90 percent of the time, depending upon sustainable wind speeds and electric grid needs

Questions and Answers

Bent Tree Wind Farm

Where is the wind farm site?
The Bent Tree Wind Farm is located about four miles north of Albert Lea, in Freeborn County, in southern Minnesota.

Why was WPL interested in this site?
The decision was made to develop the Bent Tree site because of the strong and persistent prairie winds of southern Minnesota. This wind resource enables the company to generate more wind energy for its Wisconsin customers in a cost effective manner. This site also provides “room to grow” for any potential expansion of our renewable energy portfolio.

How much electricity is generated by Bent Tree Wind Farm?
Phase I of the Bent Tree Wind Farm consists of 122 turbines capable of producing up to 200 megawatts of emissions-free energy. That's enough to power approximately 50,000 homes. The entire Bent Tree site has the potential to develop up to 400 megawatts if completely developed. A decision on the remaining 200 MW of wind capacity will likely be driven by Renewable Portfolio Standards.

How many turbines are there at Bent Tree Wind Farm?
There are 122 turbines spread out across approximately 32,500 acres.

What kind of turbines are they?
They are Vestas V82 turbines capable of producing 1.65 megawatts of electricity.

Who will receive the power from Bent Tree?
The electricity generated by Bent Tree Wind Farm will be sent out over the electric transmission grid to reach areas where electricity is needed at that time. Since this is a WPL owned and operated facility, the renewable credits earned from Bent Tree go to WPL.

Will my electricity supply depend on the wind blowing?
No. All customers will continue to receive a constant flow of electricity from WPL. As wind-powered electricity is added to the grid, other generators will be turned down or off to maintain the balance.

What type of lighting is around the wind turbines?
The only lighting on the wind turbines is mandatory FAA lighting on the top of a turbine's nacelle. There is no base-level lighting on or around the wind turbines.

Are landowners still able to use the land around the wind turbines?
With the exception of a 50' x 50' parcel directly surrounding the wind turbine's base and a narrow access road, landowners are able to utilize all the land surrounding the turbine. Many farm roads can double as access roads, reducing non-usable land even further.

Who manages the operation of this wind farm?
WPL owns and operates the Bent Tree Wind Farm.

Costs and Economic Impacts

How will Bent Tree Wind Farm help the economy in Freeborn County?
During the construction process, the Bent Tree Wind Farm brought hundreds of workers into the County who needed places to sleep, eat and shop which provided an economic boost to the local economy. For the long-term, the Bent Tree Wind Farm pays property taxes annually to Freeborn County. That money is used to benefit all communities in the county.


What are the environmental benefits of wind power?
Wind power benefits the environment because it does not create any emissions or deplete our natural resources, such as wetlands and animal habitats.

Will Bent Tree Wind Farm harm birds, bats or other animals?
A risk analysis was completed during the project planning stages to determine potential impacts to animals that reside in the wind farm area. Threatened and Endangered species, birds, bats, and plant species were evaluated. The results of this study are as follows:

  • No Threatened and Endangered species were previously known to exist within the project boundary and will therefore, not be impacted by the project.
  • The presence of lakes, wetlands and wildlife management areas (WMA) in and around the project area provide habitat for nesting and migrating birds. This represents a risk to waterfowl and other bird species, however a buffer zone has been created around the WMA to minimize the risk.
  • Due to the amount of cropland within and around the project site, and limited woodlands, the project is a low-risk for bat mortality.
  • It is not anticipated that rare plant species will occur within the project boundary as they are typically found in higher quality communities (i.e. prairie remnant). The site is primarily cropland which would inhibit rare plant growth.

What other environmental studies were performed for the project?
Additional studies for impacts to wetland areas, historic archaeological sites, and noise levels were completed. These analyses concluded that wind turbine locations and collector lines will not disturb wetland areas. Crane paths used during the construction phase had temporary impacts on stream crossings, however all stream crossings have been restored to their original state. Historic archaeological sites were avoided and therefore not disturbed by construction activities. Noise levels for the occupied residences in the project area were assessed through a modeling analysis. Impacts were confined to the area immediately around each wind turbine structure. Predicted noise levels at each residence were in compliance with Minnesota regulations.