Wednesday, February 11, 2009

Blade breaks off wind turbine

PERKINS TOWNSHIP ­— Three wind turbines have stopped spinning because the blades on one of them broke apart on Saturday afternoon outside Perkins High School.

No one was hurt when parts of the fiberglass blades came off the turbine as it spun, winging the blades up to 40 yards away from the silver monopole tower, near the high school at 3714 Campbell St.

The remaining two will not spin until they are inspected and officials figure out exactly what caused the blades to break.

"We're still waiting for a complete investigation to try to determine what went wrong," said Perkins school Superintendent Jim Gunner.

"First and foremost, we've got to figure out what happened," he said. "Once we know what happened and we can safely put the two other turbines back on line, we'll do that."

Based on initial reports and photos, it sounded as though a wind gust may have caused one of the three spinning blades to flex and hit the monopole, said Joseph Ianni, chief executive officer of turbine maker ReDriven Power Inc., based in Iroquois, Ontario.

Hitting the pole could cause the blade, which is made of fiberglass with a foam core, to break and in just a few rotations throw off the balance of the three spinning blades, causing them also to hit the monopole, Ianni said. He cautioned all speculation was preliminary and no ReDriven workers had seen the blades, which were being stored at Wilkes & Co.

"We haven't seen this particular problem occur in the past at all," Ianni said. ReDriven has about 30 of the 20-kilowatt turbines in the field and a sales network of about 100 dealers in the United States, Canada and Europe.

Based on a preliminary examination, it did not appear the monopole or its foundation were damaged, Gunner said. The turbines are geared to start generating power with wind speed of about 4 mph.

Yesterday, Gunner convened Perkins Building and Ground Maintenance Supervisor Greg Linkenbach, Honeywell consultant Chris Hess, Wilkes & Co. Vice President David L. Rengel and John Fellhauer, of Fellhauer Mechanical Systems Inc.. to begin examining the blades, turbine and tower.

Rengel and Linkenbach said they were out at the turbines on Saturday and everything appeared in working order. A ReDriven worker also was at the site last week as the turbines were hooked up to the schools' power network, Ianni said.

The three turbines were installed Jan. 23 as part of major renovations designed to save on energy bills in Perkins Local Schools.

The turbines' electrical connections were hooked up and ready on Wednesday to begin generating power for the school, its field house and maintenance shop, and nearby Briar Middle School.

However, Saturday — with winds gusting out of the south — was the first day truly windy enough to test the machines.

The turbines became an attraction, with curiosity seekers driving into the high school parking lot to see the three, whose rotating 20-foot blades sometimes appeared to be synchronized, the officials said.

"It was kind of like a community event, people coming through," Rengel said. "Everybody was impressed. They said, 'Geez, these things are quiet. They look neat.'"

One 4-foot section of a blade was found in the high school student parking lot, where it hit about 20 yards away from the pole, then skidded another 20 yards, Gunner said. Another was almost directly beneath the turbine, while the third piece sailed about 25 to 30 yards into the end zone of Perkins' football stadium.

The other two can be shut down by creating an electric load within the generator, essentially locking the blades into place. The turbines also then turn to be off the direction of the wind, Rengel said.

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