Wind Energy

View of the wind turbine as the sun sets.

Luther College Wind Turbine

The Luther College wind turbine was installed on September 19, 2011 and commissioned by General Electric on November 1, 2011. Located on the bluff west of campus, the turbine symbolizes Luther’s commitments to sustainability and represents a significant measure to reduce campus greenhouse gas emissions and long-term electricity costs. 

The 1.1 mile-long transmission line was installed underground to protect the beauty of the surrounding area. The line carries the wind-generated electricity north and then under US-52, south along Valley View Drive, under the Upper Iowa River, and then east to the Alliant Energy distribution line that serves the Luther campus.

On average, the wind turbine generates 3.6 million kilowatt hours (kWh) of electricity per year, which is about 27 percent of all power consumed on campus. The offset greenhouse gas emissions represent approximately 10 percent of Luther’s peak carbon footprint.

System Information

  • 1.6 megawatt General Electric XLE wind turbine
  • 80 meter hub height
  • 82.5 meter rotor diameter
  • 6.1 meter per second average annual wind speed at 80 meters elevation
  • The tower was manufactured in Canada, the nacelle in Florida, and the blades in Iowa. 

Financial Information

  • In order to complete this $3.2 million project Luther College established a for-profit corporate entity, Luther College Wind Energy Project, LLC (LCWEP). Formed in 2005, LCWEP receives Iowa’s 476C tax credit for renewable energy, which adds about $50,000 per year to the project’s bottom line. 
  • The U.S. Department of Agriculture awarded LCWEP a $500,000 grant and a $928,000 guaranteed loan under their Rural Energy for America Program.
  • The project also made use of a $971,249 grant from the U.S. Treasury Department that was available for a limited time through the American Recovery and Reinvestment Act. 
  • Decorah Bank & Trust and the Iowa Energy Center’s Alternative Energy Revolving Loan Program provide financing. 
  • The project has a 13-year payback and is projected to save Luther College $1 million over the 20-year life of the turbine.

Environmental Impact

  • All forms of electricity generation have environmental impacts. Wind turbines pose unique dangers to birds and bats. 
  • According to a study, wind turbines in the US are responsible for an estimated 214,000 to 368,000 bird deaths each year. This is a small fraction compared with the estimated 6.8 million annual deaths caused by collisions with cell and radio towers and the 1.4 to 3.7 billion fatalities from cats. 
  • For an excellent overview of the impact wind turbines have on wildlife, see the following study by the American Wind Wildlife Institute
  • In addition, a student/faculty collaborative research project at Luther is actively studying bat mortality caused by Luther’s wind turbine.

Additional Information

  • The blades rotate between 9-18 rpm, with a maximum tip speed of 172 mph.
  • The nacelle is the size of a mobile home (12' x 30').
  • The swept area is 268'.
  • The height of the hub is 262'.
  • The height to the tip of the blade (when pointing directly up) is 398'.
  • It took 12 trucks to ship the crane and one week to assemble it.
  • It took 11 trucks to ship the blades, the tower segments, and other key turbine components and one week to erect the turbine.
  • The foundation consists of 400 cubic yards of concrete, or 50 truck loads.
  • This ~5 minute YouTube video shows key steps in the erection of the wind turbine.
  • This ~1 minute YouTube video shows the turbine fully constructed.

Community Wind Renewable Energy Certificates

Luther College purchases all of the Renewable Energy Certificates (RECs) from a single turbine community wind project owned by WindVision, LLC. The turbine is located 65 miles away in St. Ansgar, Iowa. Luther began purchasing the RECs in 2009 as one of several tangible steps it took to implement its obligations under the American College and University President’s Climate Commitment, and also in conjunction with meeting LEED standards associated with the construction of the Sampson-Hoffland Laboratories. 

The 750 kW wind turbine generates power that is consumed locally. On average, the wind turbine generates around 1.8 million kilowatt hours (kWh) of electricity per year. Luther uses the related RECs to offset greenhouse gas emissions associated with the same volume of electricity purchases. Luther’s purchases of these RECs reduce Luther’s peak carbon footprint by approximately 5 percent.

Interesting Facts:

  • It averts 2.5 million pounds of coal per year (100,000 cubic feet)
  • The nacel is the size of a mobile home (12' x 30')
  • The swept area is 268'
  • The height of the hub is 262'
  • The height to the tip of the blade (when pointing directly up) is 398'
  • It took 12 trucks to ship the crane
  • It took one week to prepare the crane and one week to erect the turbine
  • The foundation consists of 400 cubic yards of concrete, or 50 truck loads

Did You Know?

The turbine will enable Luther to reduce its campus carbon footprint by another 14-15 percent.