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Wind (onshore)United StatesEIR-0807

Vestas investigates fourth blade failure at Iowa wind farm since 2019

Oct 2020Published 15 Sept 2026Responsible editor: Chief Editor

SignificantMechanical
Estimated damageEstimated by the register's adjusterHow? Know the real figure?
Figure hidden: shown to subscribersMedium confidence
turbine out of service for about •• daysShown in the record →Full estimate
From the recordRoot cause hiddenFailed part hiddenThe maker is named in 30 other entries (being named is not a finding of fault)
Where
Beaver Creek wind farm, Greene County, Iowa
Operator
MidAmerican Energy
What
Turbine blade broke away and fell
Injuries
None reported
Cause
Under investigation

Companies named in the reporting of this entry (being named is not a finding of fault): MidAmerican Energy, Vestas

What happened

MidAmerican Energy halted 46 turbines at its Beaver Creek wind farm in Greene County, Iowa, on 15 October 2020 after a turbine blade broke away and fell into a harvested field. This was the fourth blade failure the utility experienced since October 2019, all involving blades manufactured by Vestas. The utility said the broken blades had been exposed to a direct or nearby lightning strike. The idled turbines, mostly rated at 2 MW each, meant more than 90 MW of generation was taken offline temporarily.

Following inspection, most turbines were returned to service after confirming no blade damage, while some remained offline for blade repair or replacement. MidAmerican and Vestas said they were working together to determine the root cause and implement corrective measures. Injuries were not reported on in the source.

Contributing factors

MidAmerican stated the affected blades had been exposed to a direct or nearby lightning strike. Vestas said it was inspecting turbines within proximity to significant lightning events under its established lightning inspection protocol, noting that while lightning protection systems normally prevent damage, some risk cannot be fully eliminated in severe events. The root cause analysis was still ongoing at the time of reporting.

Lessons learned

  1. Wind turbine blades at onshore sites can fail after direct or nearby lightning, so operators should inspect all blades within range of storms before restart.
  2. Repeated blade failures at the same wind farm call for a joint root cause study with the blade maker to find and fix the weakness.
  3. A blade that detaches can land in fields, so site rules must limit access and trigger checks after lightning or high winds.

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

Not yet known

  • Turbine model and age
  • Exact duration of outages
  • Cost of repairs and lost generation

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

Source

Utility Dive (utilitydive.com)

Site page: Beaver Creek Wind (status, dates and other incidents)

Published 2026-09-15. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.

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Chart to reuse with this story: Wind (onshore) incidents in the United States, by year, free with a credit (PNG).

Wind (onshore) incidents in the United States: 102 entries, with a free alert for the next one.

Wind turbine fires: the counts, the latest entries and a free alert for the next one. Also: wind turbine blade failures and lightning strikes on energy assets.

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