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Wind towers near Minot need fixing

MINOT, N.D. Wind towers south of here are undergoing repairs. The wind generators on the east side of U.S. Highway 83, about 10 miles south of Minot, have not been spinning to produce electricity for the last couple of months. Crews have been working to replace gear boxes.

"I'm glad to see them being repaired," said Bruce Carlson, president of the Verendrye Electric company. "A lot of folks have been wondering what the problem is. They're not perfect. It's sad to see mechanical failures and we've had our fair share."

Problems with the three-year-old towers were discovered during regular inspections last November.

The 25,000-pound gear boxes, which churn when the blades are rotating, were showing signs of wear. Some of the gear teeth were stripping out, said Ron Rebenitsch, a Basin Electric engineer from Bismarck.

"With the gear teeth stripping out, the turbine could run wild and self-destruct," he said. "Those turbines are under a tremendous amount of stress, and there are many parameters for a turbine to operate safely. It's a complex mechanical device, subject to failure."

The crumbling gear boxes, which carry a price tag of $100,000 apiece, were found to have defects due to metallurgy. They were under warranty, but replacements had to be shipped from Europe via ocean freight.

The defective gear box on the north wind tower was removed and replaced last Friday and a similar procedure began on the south tower Monday. A huge crane carrying 250,000-pound... more [truncated due to possible copyright]  
"I'm glad to see them being repaired," said Bruce Carlson, president of the Verendrye Electric company. "A lot of folks have been wondering what the problem is. They're not perfect. It's sad to see mechanical failures and we've had our fair share."

Problems with the three-year-old towers were discovered during regular inspections last November.

The 25,000-pound gear boxes, which churn when the blades are rotating, were showing signs of wear. Some of the gear teeth were stripping out, said Ron Rebenitsch, a Basin Electric engineer from Bismarck.

"With the gear teeth stripping out, the turbine could run wild and self-destruct," he said. "Those turbines are under a tremendous amount of stress, and there are many parameters for a turbine to operate safely. It's a complex mechanical device, subject to failure."

The crumbling gear boxes, which carry a price tag of $100,000 apiece, were found to have defects due to metallurgy. They were under warranty, but replacements had to be shipped from Europe via ocean freight.

The defective gear box on the north wind tower was removed and replaced last Friday and a similar procedure began on the south tower Monday. A huge crane carrying 250,000-pound counterweights was being used in the transfer.

"Gear box problems are not uncommon," said Randy Bush, a resource coordinator for Basin Electric. "At Edgeley, where they have a lot more towers, they have the same issues to deal with that we have."

Wind turbines are fitted out with multiple sensors, any of which can shut down the turbines.

Despite the operating problems with the Minot towers, Rebenitsch is a supporter of wind power.

"It has a tremendous future but, like any form of generation, there's challenges we have to meet," said Rebenitsch. "It's a tremendous potential. Technology has advanced rapidly. What we need is additional transmission lines to tie into the overall system."

Carlson agreed that wind power has a future, but he said wind is not the final answer to the area's energy needs.

"The bottom line is, it proves the need for coal-fired based load generation," Carlson said. "It shows the advantage of a diversified system."

When the repairs are completed on the second wind tower, technicians will begin testing to make sure the new gear boxes are working. If no other problems develop, both generators could be producing electricity by the end of the week.

Source: http://www.in-forum.com/ap/...

FEB 8 2006
http://www.windaction.org/posts/1227-wind-towers-near-minot-need-fixing
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