The turbine, which ran out of control on May 6 in moderate winds before the tower folded after a blade hit its middle section, was a slightly modified version of the standard GE 1.5 MW, says the company's Ken Kaser, head of wind farm operations.
"We have not seen something like this before. It was something to do with the machine's operation," says Kaser. "We're still trying to find out the cause." The turbine's nacelle has been taken back to GE's wind turbine works in Tehachapi, California, for detailed examination. Kaser is particularly anxious to establish whether the machine behaved as expected in the given circumstances. "We need to find out what caused it and at the subsequent things that happened. Did things behave in the way we expected?"
The remaining 70 turbines at the 106.5 MW wind station, which started full operation in April, are all running as normal. "We would not be operating the machines if we felt there is any risk," says Gleitz.