LAC QUI PARLE VALLEY -- It went largely unnoticed, but earlier this year the Lac qui Parle Valley School District made its last payment on the 225-kilowatt wind turbine that has in many ways become something of an icon of the school on the western prairie.
Superintendent of Schools Robert Munsterman said the turbine paid for itself on schedule in 10 years, but adds a word of caution. Incentives provided for the project helped make that possible.
The payback was made possible by the savings in electricity, and by the incentives offered to replace tax advantages a private venture would receive for a wind turbine project.
The turbine produces about 25 percent of the electricity consumed by the school.
The turbine was erected in the winter of 1997 at a cost of approximately $249,000. The school received an $189,000 loan at zero percent interest from what was then known as the Minnesota Department of Public Service. The state also offered a $60,000 grant.
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The turbine produces an average of 452,800 kilowatts per year, which is about 23 percent of the maximum annual capacity estimated for the site. The rate of efficiency is what would be expected for the 13mph average wind velocity found at the site and the height of the tower, according to information compiled by the district.
The turbine has been an important learning tool for the school, according to Munsterman. Science teachers have incorporated the turbine into their class work, although the school does not have a curriculum built exclusively around it. Munsterman said the district is looking for a way to put real-time and other information from the turbine on-line, so that others could learn from it as well.
Today, a 225-kilowatt turbine is considered quite small, said Munsterman. At the time it was erected, the very largest turbines were 750 and 950 kilowatts.
Today, large turbines are rated at 1.5 megawatts.
Munsterman said the economics of wind power clearly favors larger turbines. Wind speeds increase with height, and wind power is proportional to the cube of wind speed. A tower with an average wind speed of 15 miles per hour contains nearly 60 percent more energy than a site with an average wind speed of 13 mph, according to Windustry of Minnesota.
Asked whether he would encourage other schools to erect wind towers, the superintendent quickly answered with a flat "no.'' "Not with school finances today,'' he explained.
The turbine at Lac qui Parle Valley stands on a 152-foot tower. The tower supports an 18,000 pound generator and three rotor blades, each 46-feet long and weighing about 4,000 pounds.
