Wind turbine tower collapses at Steele Flats Wind Farm in Nebraska

What happened

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.

Contributing factors

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.

Lessons learned

1. Wind turbine towers are designed to crumple into their own footprint, so local setback rules of more than 1,300 feet from occupied structures limit harm during unexpected collapses.
2. Tower failures can occur without extreme weather, so operators should inspect tower and foundation integrity at regular intervals throughout the turbine life.

More lessons on structural integrity and turbines, weather and external hazards, from every incident on the register.

Not yet known

• Turbine model and age
• Cost of the damage and restoration
• Length of downtime

This entry is updated when these are reported. Get an alert for the next one like it.

Source

ketv.com