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GE continuing probe of recent wind turbine breaks in U.S.

OAKWOOD – General Electric said it is doing “thorough investigations” of three recent incidents involving GE wind turbines breaking in the U.S. – including one at the California Ridge Wind Farm in Vermilion County – and has identified “a suspect population of roughly 1.5 percent of our total blades in our wind turbine fleet.”

The two blades that broke on a turbine near Oakwood about 9 p.m. Nov. 20 marked the third GE turbine to break in a 17-month span at wind farms in East Central Illinois.

It was also the third GE turbine blade break in the U.S. since early November.

GE Power & Water spokesman Katelyn Buress confirmed that all of those broken blades were on 1.6-megawatt GE turbines – either GE’s 1.6-100 model or 1.6-82.5 model.

Buress said that at the end of the third quarter of 2013, there were 1,087 GE 1.6-100s installed, the majority in the U.S., with 134 of those at the California Ridge Wind Farm. Buress said all wind farm owners that use the model have been notified of the recent blade breaks, adding that GE is working with its “customers to perform thorough investigations of the recent breaks.”

“We have identified a suspect population of roughly 1.5 percent of our total blades in the our wind turbine fleet,” Buress said. “We have notified those customers with turbines within this population and are closely working with them to keep their turbines running reliably and safely.”

Buress said the break at California Ridge was determined to be caused by “extreme weather,” but “our teams are still undergoing the root cause analyses” for recent blade breaks at the Echo and Orangeville wind farms in Michigan and New York, respectively.

GE officials declined to say what “extreme weather” conditions caused the blade to break at California Ridge, which is owned and operated by Chicago-based Invenergy.

“It’s because the analysis is still ongoing,” said Lindsay Theile, GE Power & Water spokesman. “We’re continuing to work with Invenergy as we continue the analysis.”
Another turbine blade broke in the California Ridge Wind Farm near Potomac in November 2012, following a GE blade break in June 2012 at the Settlers Trail Wind Farm near Sheldon in Iroquois County, operated by Chicago-based E.On Climate & Renewables.

Last March, GE issued a statement saying that an “isolated manufacturing issue” caused the two wind turbines to break in 2012. GE said it had “reviewed the wind farm fleets at both sites to ensure their continued reliability and performance” and “have addressed the manufacturing issue to prevent this from happening in the future.”

GE’s 1.6-megawatt turbines are built to operate at wind speeds of 25 meters per second and shut down at wind speeds higher than that, Buress said. She said the turbines are “designed to withstand wind of much higher velocities, as well, but “extreme weather such as lightning strikes, although rare, do occur.”

Allan Curtis, assistant climatologist at the Midwestern Regional Climate Center in Champaign, was unable to provide any weather information specifically for the Oakwood area for the evening of Nov. 20, but he said hourly data from the nearest airport – in Danville – showed wind speeds did not reach greater than 10-15 mph on Nov. 20. The Danville airport did report “sporadic rain starting 5 p.m. on the 20th on through the rest of the night,” Curtis said.

Three days earlier, tornadoes were spotted in Vermilion County between Westville and Danville and near Hoopeston, as well as in Gifford in northeastern Champaign County, said Patrick Bak, a meteorologist for the National Weather Service at Lincoln. But there were no tornadoes reported in the Oakwood area, Bak said.

That same day, the Danville airport reported increasing wind gusts – of up to 45 mph – before the airport’s wind data “went offline” early that afternoon and through mid-afternoon on Nov. 19, Curtis said.

Buress said blade breaks in wind farms are rare.

“GE’s global fleet of more than 22,000 wind turbines have recorded more than 500 million safe operating hours and achieved an availability rating of more than 98 percent,” Buress said. “Our success in the industry is built on our high reliability and safety record. Right now, we’re focused on the root cause analyses of these three breaks.”

All turbines in California Ridge remain in operation, with exception of the turbine that broke last month, Theile said.

Invenergy said the blade broke off and fell to the ground near the base of the turbine, which is located near the intersection of 2150 North Road and 900 East Road near Oakwood.

“We believe that as this blade fell, it hit a second blade on the same turbine, causing that second blade also to break off and fall to the ground near the base,” the statement said. “As designed, the turbine automatically ceased operation. No one was injured.”

Invenergy’s 217-megawatt, 134-turbine California Ridge Wind Farm has been in operation since 2012. There are 30 turbines in Champaign County and 104 in Vermilion County.