BAD AXE – The cause of two broken blades on separate Bloomfield Township wind turbines in October was revealed Wednesday night at the Huron County Planning Commission meeting.
Fifty blades in the Deerfield Wind Energy Project were discovered to have the same issue as the two that broke and dangled from their towers near the intersection of Redman and Iseler roads, said Dave Philpott, project manager for the park, which is owned by Algonquin Power of Ontario, Canada.
A total of 216 blades are in the 72-tower project.
Lack of adhesive was discovered to be the problem, and the defective blades are being repaired, said Jason Sterling, site construction manager of Vestas, the company that is constructing the turbines.
“They will not be replaced. They will be repaired in the air,” Philpott said.
Both broken blades experienced the same mechanical failure, which was determined to be a “very limited anomaly with our manufacturing process,” Sterling said.
“There was basically a lack of the adhesive that we use in the main structure of the internal blade,” he added.
One of the blades broke Oct. 21, and the other on Oct. 22 when the turbines were first tested before going online.
The blades stayed connected, and did not fall.
The blades were later taken down and dissected by Vesta’s design and engineering teams.
Measurements are being taken on remaining blades, which will then be sent to engineers to determine whether they could be used, Sterling said.
“We expect to have the rest of the investigation done by the end of this week, and are on target for full completion of the project – that means all 72 towers commissioned by the end of the year.” Philpott added.
The two blades that broke were the first two to be turned on in the startup phase of the project.
The first turbine broke and bent in half during the afternoon of Oct. 22 while in the process of the startup procedure.
The second blade broke at its midway point, and stayed attached, just as the first one had after about 24 hours of run time.
Wind speeds were 11 meters per second, or 18-22 miles per hour, which are not considered to be extreme, Algonquin officals have said.