WILLMAR -- Willmar's two wind turbines will be shut down periodically this week for routine inspection and maintenance.
One or both of the turbines will be down at any given time this week to allow the maintenance crew to enter and work on what they need to do, said Wes Hompe, staff electrical engineer with the Willmar Municipal Utilities. He said crews have tools, oil, filters and other items to do the work. The turbines have a schedule that requires certain maintenance procedures to be performed at regular intervals. Some maintenance, like the work being done this week, is required every six months, while other maintenance is required once a year or every three years.
The nearly $10 million turbines were built by Willmar Municipal Utilities at a site located just north of Willmar Senior High School and are projected to produce almost 10 million kilowatt-hours of electricity per year, which equals about 3 percent of Willmar's annual needs.
Maintenance crew members are employees of DeWind, the company that built the power unit on top of each turbine. DeWind originated in Germany and has a plant in Round Rock, Texas, where Willmar's power units were built.
Crew members Alden Zeitz, manager; Kristjon Luetgers, operations technician; and Dwaine "Dewey'' Higgins, operations technician, strapped on tool belts and safety harnesses before ascending the interior of the 262-foot north tower Tuesday. Each tower has an elevator.
The crew includes Harry Hoffmann, supervisor of installation and maintenance, from Germany. Hompe said the experts on the inner workings of the power units are from Germany.
"If our local technicians run into something they don't quite understand, they generally will call Germany,'' Hompe said.
Willmar utility employees who have received training on the operation of the turbines would normally participate in the maintenance work, but are needed for the annual overhaul project at the downtown power plant, said Hompe.
"Since we know this happens every six months, the next six-month inspection they will be going up there,'' he said.
The turbines require a sustained wind speed of 8 mph or above to start turning. The turbines reach their maximum output at 26 mph and shut down about 55 mph.
The turbines were more than three years in the making from initial studies to construction. Officials say the turbines will help the utility comply with the state mandate of producing 25 percent of the state's power from renewable resources by 2025.