Problems continue to plague Willmar’s wind turbines

“In the grand scheme of wind turbines, ours are quite dinosauric. … When they were put up, we were carrying flip phones and we thought they were pretty cool.”

“If we didn’t have the staff that we do, we’d be having a conversation about, ‘Is this worth it anymore?’” Marti said regarding all the repairs needed recently and potentially having to call in outside help to fix the turbines.

Willmar Municipal Utilities’ wind turbine technicians Matt Krupa and Nick Hillenbrand are trained to the highest level for the DeWind turbines owned by the utility.

”We are quite fortunate to have these guys that are passionate about the turbines and take it personally if they don’t run,” Marti added.

General Manager John Harren said if Willmar Municipal Utilities had to rely on outside resources to keep the turbines running, it is likely they would no longer be functioning.

He also explained that Willmar Municipal Utilities is consistently monitoring the cost of power generated by the turbines, which is currently around 16 to 17 cents per kilowatt-hour. A major contributing factor regarding when to discontinue the use of the turbines is when the power generated by them begins to cost more than buying power from the Missouri River Energy Services.

“We look at the cost being put into those turbines and, if the output remains as low as it is, we might hit that here in 2023,” Harren commented.

At the Aug. 14 Municipal Utilities Commission meeting, Marti informed the commission that wind turbine three was available 94.1% in July and turbine four was available 67.9% of the time in July for a total output of 160,592 kilowatt-hours. The total so far this year is approximately 1.509 million kWh.

“Typically July and August, kind of through the heat of the summer, are our lowest production months,” Marti said. “Although our number for the month seems low, it is not completely out of the realm of a normal July.”

In July of 2022, the turbines produced a total of 343,435 kWh of power, which was quite a bit more than in previous years when 156,572 kWh was produced in July of 2021 and 184,774 kWh in July 2020. The total amount of power generated by the turbines in 2022 was 7.279 million kWh.

Beginning of the end?

At the beginning of this year, the breakers in both wind turbines were failing. New breakers were ordered in November 2022 and were expected to be delivered within about four months, but they did not arrive until just a few weeks ago.

In the meantime, Willmar Municipal Utilities had found a company called Phase Shift Power owned by Mitchell J. Knudson of Richmond, Wisconsin, to repair the breakers and get the turbines running. Since the repaired breakers are still functioning, the new breakers are being held in storage until needed.

Marti last week explained that, if Willmar Municipal Utilities were to discontinue the use of the wind turbines to generate power, the breakers are worth more for resale if they have not been installed.

Other problems that have been plaguing the wind turbines and keeping them from operating at their full potential are pitch sensor failures, positioning sensor failures and electrical faults, according to Marti. The bad positioning sensor has been replaced with a new one, but the electrical fault issue has been more elusive for the wind turbine technicians.

Marti explained that Willmar Municipal Utilities is planning to reach out to Knudson to see if he can help with the electrical fault issue.

“We’re not sure he can help us … but he’s a lot smarter than we are when it comes to those in -depth electrical issues,” he said.

During the wind turbine report in July, Marti explained that the large bus (electrical) panel in wind turbine four has about 50 different cards with 150 different connections that plug in different components. The technicians took out each card, tightened up the electrical connections and cleaned them up, finding three connections that were slightly loose.

“It takes a lot of time to fix some of these things,” Marti said. “(It’s) not a major component, but it really can affect your availability and output.”

Willmar Municipal Utilities has struggled finding parts for the DeWind turbines for several years, in large part due to the company that made the turbines going out of business. Willmar Municipal Utilities had frequently reached out to a technical support person in Germany when problems arose, according to Marti, but that person is now retired.

“The only other option we have is a former DeWind engineer that lives in the United States that actually has trained our staff up to level 10 and is an asset for us to reach out to – the guys will reach out to him when they really get stumped, and he’ll sometimes be able to help us through that,” Marti said.

There are a number of wind turbine companies, but none of them have the knowledge or ability to work on the local turbines, according to Marti.

“We feel that we’re in a good place as far as diagnosing what we have, but we’re running into some repeat issues this year and it will be interesting at the end of the year to see what our cost of power is – where we land,” he concluded.