The on-again, but reliably off-again wind turbines operated by Willmar Municipal Utilities appear to be headed for the scrap heap, five years sooner than expected upon installation in 2009. For the past several years, the two 263-foot tall turbines have given the west central Minnesota utility fits with a myriad of problems, often resulting in lengthy and expensive breakdowns.
But evidently the West Central Tribune may not have to continue compiling the list of failures much longer.
Structural issues that may be cost-prohibitive to repair may mean the permanent shutting down of Willmar Municipal Utilities wind turbine No. 3, and wind turbine No. 4 continues to have electrical issues that are being worked out.
Although wind turbine No. 3 generated more power in June than turbine No. 4, it is now shut down until the structural issues can be addressed — if they can be addressed.
It’s always something, and often, something more complicated than previously encountered. But diagnosing the problem is the easy part, compared to finding parts for wind turbines whose manufacturer went out of business long ago.
Electrical Engineer Jeron Smith informed the Utilities Commission on July 8 that a blade pitch issue initially shut down No. 3, but more significant issues were discovered by Willmar Municipal Utilities wind technicians when they went up into the turbine to investigate.
One-inch steel brackets that connect the Fiberglass nacelle housing on the top of the tower to the frame are all cracked and bent, according to Smith. The nacelle houses all of the generating components in a wind turbine, including the generator, gear box, drive train and brake assembly.
“It’s in really bad shape,” Smith said. “It’s beyond our wind techs’ ability to repair.”
Last year utilities officials warned that another major problem would likely result in shutting down the turbines for good. The never-ending maintenance problems, early retirement and cost of dismantlement prices Willmar’s wind power out of the market.
The 2023 year-to-date cost of power for the wind turbines is averaging 8.33 cents per kilowatt-hour, which is higher than the wholesale cost of power purchased by Willmar Municipal Utilities. Power is purchased for approximately 6 to 7 cents per kilowatt-hour, according to Facilities and Maintenance Manager Kevin Marti.
“We’ve always said that once our annual costs exceed our wholesale purchase power cost, we need to take a look at it, and this year, we’re going to exceed that,” said General Manager John Harren.
If turned off now and Willmar Municipal Utilities spent the expected $2 million to decommission the wind turbines, the average cost of power over their lifetime would be 17 cents per kilowatt-hour, according to Marti.
The turbines were originally projected to stay in service for 20 years until 2029, but staff say the same model has been known to remain operational for 13 to 16 years. In the meantime, Willmar Municipal Utilities plans to install four diesel generators to provide reliable baseload power on an as-needed basis going forward.
Early retirement guarantees the cost of producing wind power will far exceed