Second Wind Tower Blade Suffers ‘Structural Failure’ At Prairie Breeze Wind Energy Farm

“It sounded like sheet metal falling down.”
That’s how rural resident Jerry Kallhoff described the structural failure of a wind turbine blade which broke off a Prairie Breeze Wind Energy tower Sunday afternoon at a location southwest of Elgin.
The turbine, the project’s 11th unit, remains non-operational at this time as we work with the turbine manufacturer, GE, to determine the cause of this incident.
Turbine #11 is located about a quarter-mile south of the intersection of 835th Road and 515th Avenue in Antelope County, approximately 8 miles west of the city of Elgin.
Kallhoff said he was out in his yard working when he heard a loud noise come from the south. When he looked up, he saw pieces of a wind turbine blade falling to the ground from a wind tower located just over a mile from his house.
It marks the second time in less than two weeks that there has been a structural failure on a wind turbine blade.
On April 21, a similar failure took place on the wind farm’s 51st unit located northwest of Petersburg in Boone County.
In both cases, immediately after the structural failure, the wind turbines ceased operation.
During the construction phase of the wind farm, it was determined that a number of GE wind turbine blades would have to be replaced due to abnormalities discovered after the blades were installed on  wind turbines.
At that time, December 2013, Invenergy announced that General Electric would be replacing a limited number of turbine blades. According to GE spokesperson Katelyn Buress, GE identified a number of blades that have been impacted by an anomaly in the manufacturing process.”
The Elgin Review has learned the Prairie Breeze wind turbines use the same model blade, a 48.7 meter blade, which have been found to have structural defects at other wind farms in the U.S.
In December, Joseph Bebon of North American Windpower (NAW) reported that the Invenergy-owned Orangeville Wind Farm in New York State used the same blades and had similar problems. Bebon reported that “following a thorough investigation, GE says a “spar cap manufacturing anomaly” was to blame for the recent blade breaks at the Orangeville Wind Farm in New York and Echo Wind Park in Michigan. Echo Wind Park is not owned by Invenergy.
Bebon reported that a spar cap is a “key structural element within the blade that carries the bending load of the blade.”
In November 2013, NAW reported four GE blade breaks had occurred this year, all of which involved 48.7-meter blades. Two of the affected wind farms were still undergoing construction or commissioning, and the other two were operational.