Nordex turbine collapses at Frontier II wind farm, Oklahoma

What happened

A wind turbine collapsed at the Frontier II wind farm in Oklahoma, United States, on a calm day without strong winds, according to a Notebookcheck report that relied on local media and a Nordex statement. The farm has 74 Nordex N149/4.XMW turbines, each rated at 4 MW, and has operated since March 2021. Nordex confirmed the collapse in a statement and said only material damage was reported. Nordex said a team from Nordex USA and Nordex Group had been formed to investigate root causes in close collaboration with the customer, Deriva Energy.

The operator said all employees were safe and accounted for, the site was secure and the plant remained safe and operational. The cause was unknown at the time of reporting. The date of the collapse is not reported. Local media reported that officials described the event as bizarre.

Contributing factors

Not reported. The cause was unknown at the time of reporting, and the collapse occurred on a calm day without strong winds.

Lessons learned

1. Investigate structural collapses that occur in low wind conditions by examining control, braking and yaw systems as well as tower and foundation condition, since wind loading alone may not explain the event.
2. Account for all personnel and confirm site safety immediately after any turbine failure, and keep records of where staff were at the time.
3. Share findings with the turbine manufacturer and other operators of the same model, because a failure mode in one fleet may apply to others.

More lessons on structural integrity and turbines, investigation and fleet-wide checks, from every incident on the register.

Source

notebookcheck.net