Vestas has taken around 150 turbines out of operation globally after discovering a fault on certain V150 blades.
The Danish manufacturer said it has found “bonding failure” on “blade root inserts” due to “contamination of inserts…stemming from a manufacturing process step” at one supplier.
The fault was confirmed after the investigation into the collapse of a V150-4.2MW turbine in Sweden in November. The probe has revealed the incident was caused by a blade coming loose at the 72MW Aldermyrberget project, which destabilised the unit and caused the collapse.
“As an extraordinary precaution, Vestas has paused around 150 V150-4.0/4.2/4.3 MW (Mk3E) wind turbines with one or more blades with the same blade root insert configuration as the detached blade from the collapsed turbine,” said a spokesman.
“Vestas is taking this step out of an abundance of caution and are working to have a solution in place to get these V150 wind turbines safely up and running again.”
He added that all other Vestas turbines, including V150-4.0/4.2/4.3 MW (Mk3e) with different blade root insert configurations, are unaffected and “are considered fully safe to operate”.
Affected turbines will be up and running “as soon as possible” with both replacement and repair options being considered.
“At present, we are taking logistical measures to minimise interruption of turbine installations and operation. We are exploring multiple methods to replace the blade root inserts in question,” the company said.
There have been no other incidents involving operational components with these specific steel inserts but a blade fell last week in Finland during de-installation.
“The blade was being replaced because it had the same inserts as the blade on the turbine that collapsed at Aldermyrberget,” Vestas said.
“The incident did not occur during operation or idling and we therefore don’t perceive the incidents as directly related although it’s the same blade root insert configuration. This is the first time we’ve experienced a V150 blade fall to the ground during installation or de-installation, and we have initiated an investigation of what happened.”
The Aldermyrberget blade loss is not related to recent ones at the Valhalla project in Sweden, Dundonnell in Australia or Timber Road 4 in the US, added the company.
The V150 fault is also not connected to a high intensity lightning issue, which forced the supplier to make an extraordinary warranty provision of €175m in August for upgrades and repairs.
Vestas declined to provide a cost estimate for the repairs and replacement of the V150 blades.