Wind turbine tower collapses at Steele Flats Wind Farm in Nebraska

A wind turbine at the Steele Flats Wind Farm south of Diller, Nebraska collapsed early in the morning, with the 426 foot structure including the blades coming down. The turbine went offline at around 5am. Weather did not appear to be a factor: the county emergency management director said top gusts the previous day were 35 mph and had diminished to under 20 mph by Tuesday morning, and that the towers had stood in much stronger wind. From photographs, the tower appeared to have crumpled into its own footprint, which is how such structures are designed to fail. The county required turbines to be sited more than 1,300 feet from an occupied structure. No injuries were reported. NextEra Energy, the operator and owner of the wind farm, said it would work with the property owner and the turbine manufacturer on a thorough investigation into the cause of the failure and would restore the turbine at the same location at the appropriate time. The wind farm cost around 138 million US dollars to build and started up in October 2013.

The cause of the collapse was not known at the time of reporting and was under investigation. Weather did not appear to be a factor, with recorded wind speeds well within normal operating conditions.

1. Structural failures of wind turbines can occur in the absence of extreme weather, so tower and foundation integrity should be checked by regular inspection throughout operational life.
2. Setback distances between turbines and occupied structures, as required by the local authority in this case, provide a safety buffer that limits harm when unexpected structural failures occur.
3. Early collaboration between owner and turbine manufacturer after a failure supports faster root cause identification and can inform fleet wide inspection programmes.

News report via Google News