Case Study – Failure of a 20kW wind turbine

Finch Consulting was appointed to investigate the viability of the repair or replacement of a wind turbine after it had sustained damage during maintenance carried out by the Insured.

The turbine was designed with a tow-up tower which allowed simpler installation and maintenance without the need for large cranes. The vertical tower was secured to the concrete plinth with a series of ground bolts and could be pivoted about a hinge to be lifted or lowered. It was during the process of lowering the tower using this system that the winch failed and the turbine fell about 5 m landing on the front of the spinner cone.


Wind turbine post accident

A Finch Consultant attended site and conducted a detailed inspection of the damaged turbine in-situ with some items inspected at the Insured’s premises.

Non-destructive testing was recommended to ensure the tower had no cracks on the structure as a result of the stresses and impact experienced during the incident.

Finch Consulting provided options and reasoning for, both, replacement and repair, taking into consideration the application of feed in tariffs (FIT) and planning requirements. Replacement of the turbine section would need to meet the guidelines of a new installation whereas a repair would not have required such scrutiny. It also became clear during investigations that new parts were not available because the turbine manufacturer had ceased trading. However, used parts were available from an identical turbine that was out of service elsewhere in the country.

Structural cracking on turbine shaft

Structural cracking on turbine shaft

The Insured’s documentation did not provide certification of the repair of the wind turbines in accordance with the relevant British Standards for the repair of wind turbines. Therefore it was Finch Consulting’s opinion that it would be pragmatic to place the generator overhaul with a specialist motor or generator rewinding company with the appropriate Certification for this activity.

Finch Consulting’s findings, opinions, and recommendations allowed the client to settle the claim close to the repair quotation prices and a replacement was not required. As a result of the Finch Consulting intervention, the cost of repair of the turbine was reduced to £15,000 compared to a replacement cost of £65,000.