May 3, 2011
North Dakota

Two wind turbines suffer damage

By LEANN ECKROTH/ Bismarck Tribune, www.bismarcktribune.com 2 May 2011

Two wind turbines in central North Dakota sustained damage last week and remain idle until repair crews can reach them.

A turbine located about one mile south on 93rd Street, Wilton, owned by Nextera Energy of Florida was bent and needs to be replaced, said company spokesman Steve Stengel.

The damage occurred late Thursday night or early Friday morning, Stengel said.

“We’re investigating its cause,” he said of the damage. “We’ve got to get a crane up there. We’re in the process of finding a new blade to replace there.”

Stengel could not say when a replacement blade could be found, but said the remaining 32 towers on the wind farm in Burleigh County would keep operating. The damaged tower feeds Basin Electric customers, but Nextera owns, operates and is liable for them.

Each tower generates about 1.5 megawatts. Stengel said it was not company policy to release the cost of damaged equipment or how much profit it would lose when not running.

The damaged blade was about .2 a mile from the nearest county road and .7 mile away from the nearest home, and does not pose a fall risk to residents or motorists nearby, Stengel said. He said the company was not notified of any other damaged towers.

A separate tower’s blade about 15 miles south of Minot, owned by Basin Electric, also malfunctioned and bent over itself, said Basin Electric spokesman Daryl Hill. He said it happened Saturday afternoon during the blizzard and windstorm. Cause is still being determined.

He said the blades are designed to adjust to their angles according to wind speeds. Towers will stop rotating if wind speeds exceed 55 mph. “We don’t know why,” Hill said. “We’ll give it a new blade and determine the cause of the blade failure.”

He noted one blade measures 121 feet long and weighs 7 tons.

Hill said the damaged tower won’t impair the other 81 towers of the farm in Ward County. Each can generate 1.3 to 1.5 megawatts. “They’re all independent,” he said.

“The tower that failed was about one-quarter mile away from the road. It has an ample setback. No homes are near it,” Hill said. Hill said the wind towers well exceed setback requirements mandated by the state Public Service Commission.

He said the cost to replace one its blades is $150,000 plus labor and equipment expenses for replacing and installing the equipment. Monday afternoon, he did not know when the repairs could be finished.

URL to article:  https://www.wind-watch.org/news/2011/05/03/two-wind-turbines-suffer-damage/