A wind turbine in Mower County is believed to have been struck by lightning last month, effectively turning one of the three 37-meter blades into a wet noodle hanging roughly 400 feet in the air.
The damaged turbine is located near Dexter and visible from Interstate 90.
According to paperwork filed April 30 with the Minnesota Public Utilities Commission, EDF Renewable Energy, formerly enXco, reported that one of 67 turbines in the 100.5 megawatt Wapsipinicon Wind Project failed during “extreme weather conditions” on April 24. The cause of the failure is still being evaluated, but EDF said a preliminary examination suggests a lightning strike caused the failure.
Such events are required to be reported to the Minnesota Department of Commerce within 24 hours, which a state staff member confirms took place.
Steven Powell, EDF’s Operations manager, said that it doesn’t appear any other parts were damaged in the storm.
In its filing with the PUC, EDF said that quotes have been requested from three crane companies to replace the broken turbine blade. Such work will not begin until after May 15, based on county road restrictions, according to the filing. It projects the work to start in late May or early June, though repair time “is dependent upon crane availabilities and lead time of the replacement parts.”
It’s also unclear how much the repair project will cost. The turbine in question is a General Electric 1.5 MW turbine. New, fully installed industrial-size wind turbines, which stand about 400 feet tall, cost up to $3 million.
The same wind project, built in 2009 and owned by Xcel Energy, underwent more traditional – albeit costly – repairs last fall. Previous PUC filings show that a 310-foot crane was brought in to replace gearboxes at a rate of approximately $360,000 apiece.