Enercon E126 blade break in Germany prompts fleet-wide turbine monitoring

A blade snapped on an Enercon E126 7.5MW turbine at the Schneebergerhof wind farm in Rhineland-Palatinate, south-west Germany, in December, reported by Wind Power Monthly in May 2014 as having occurred the previous December. The broken blade was found approximately 40 metres from the turbine. Juwi, which operates the wind farm, said that following intensive investigations Enercon could not determine the cause because the remnant of the blade was too badly damaged. At the time of the break Enercon said it had checked all similar machines as a precaution and no irregularities had been detected. Enercon subsequently fitted a new sensor system to all 56 installed E126 turbines, described as detecting incipient damage and sending a notification to Enercon and, for Juwi-owned turbines, to the control centre in Woerrstadt, so operators can take evasive action. The repaired turbine was reported to be operating again and was to be re-inspected after a certain period.

The root cause of the blade break could not be established because the remnant of the blade was too badly damaged for analysis. The E126 uses segmented steel-composite hybrid blades.

1. Fit structural monitoring that can detect abnormal blade stresses or incipient damage and alert the control centre before a failure occurs.
2. After an unexplained component failure, inspect all turbines of the same model as a precaution even while the cause remains unknown.
3. Plan for prompt recovery and preservation of failed components, because badly damaged remnants can prevent root cause determination and leave a fleet-wide risk unresolved.

windpowermonthly.com/article/1296348/enercon-monitors-e126-turbines-following...