BAD AXE – As crews continue to probe why a 400-foot wind turbine fell on a farm field, county planners talked publicly for the first time Wednesday about the incident and aftermath.
County Building and Zoning Director Jeff Smith said he was out of town when the turbine fell, on Feb. 25, but went out to the site in Oliver Township on Feb. 29 with township officials.
Smith says developer Exelon Wind Generation hired third party investigators to join its own team and crews from Denmark-based Vestas, the turbine manufacturer. The Vestas V82 turbine that fell was one of 2,500 installed in the U.S. and 7,000 worldwide, he said.
“These are rare,” Smith said of turbines falling. “This is the second failure – ever, for this particular model.”
The first happened in Spain, he said, due to ineffective welds. Smith showed photos of the scene he saw on Monday to county planners Wednesday. He said one showed 140 exposed bolts, each 1 5/8-inch thick, which secured part of the 262-foot tower. Welds on the turbine were intact, he said.
Exelon says the same turbine model is designed to withstand Arctic weather conditions and has successfully withstood hurricanes. The structure in Oliver Township met building codes to withstand 90 mph winds, Smith said.
According to Smith, the farthest a piece of the turbine fell was 452 feet from the base of the tower. Investigators are analyzing data from a black box inside the turbine, similar to those in aircraft, he said. When Exelon lost communication with the turbine at 5:12 a.m. Feb. 25, it was shut off and in an idle, state according to Smith.
Exelon made a rare appearance at the county planning commission meeting Wednesday. Communications Manager Kristen Otterness said the company has 809 turbines in the U.S.
“We constantly monitor the operation of our turbines, we do regular maintenance and regular inspections on them to ensure that they operate safely and as they are designed to do,” Otterness said.
“Again, once we do know the cause … we will be applying lessons learned form this event across our fleet and with the industry as well.”
The 485,000-pound, $1.5 million turbine spilled 25 gallons of greases, oil and coolant onto the farm field where it fell, near Berne and Gagetown roads, according to the Department of Environmental Quality, which was on site this week and says the spill has been contained. There is “no imminent drinking water or environmental health threat,” a DEQ official told the Tribune. According to Exelon, the turbine held about 400 gallons of oil. (Full story here: http://bit.ly/1TVboJD.)