Wind power Vestas – Blade incident on V112-3.0 MW prototype in Lem, Denmark

On Wednesday 8 September 2010, a blade piece detached from Vestas’ V112-3.0 MW prototype wind turbine located in Lem, Denmark. Vestas confirms that this manually produced prototype blade – one of the first three blades manufactured for the V112-3.0 MW prototype programme – according to general procedure has not been subjected to Vestas’ normal verification and reliability testing programme.

Based on this incident, in the future, Vestas will, however, ensure that prototype quality meets higher demands than those applied for this prototype production. Manually produced prototypes will, however, always involve a significant higher risk of failure than by automated production processes.

Vestas’ specialists and forensic experts have analysed the root cause and their preliminary and unambiguous conclusion is that this is a stand-alone manufacturing mistake caused by a human error during the manual production process of the blade. Among other things, this is clearly seen from the way the blade has broken.

To make sure there is no doubt about the root cause, the management of wind energy company Vestas Technology R&D has decided that Vestas’ internal investigation will be followed up by a third party, external, expert investigation. Furthermore, the result of this investigation will also be communicated to the stock exchange as soon as it is concluded.

It is important to emphasise that when the V112-3.0 MW wind turbine is put into serial production, this kind of failure will not be possible in Vestas’ automated manufacturing process. The V112-3.0 MW wind turbine, and consequently, the blade was released for sale in the middle of August 2010 following a comprehensive test programme validating the design inclusive of the blade design.

The design has thus been certified according to global wind turbines industry standards, and therefore Vestas’ conclusion is that the failure cannot originate from a design flaw.

On the basis of the conclusion of this investigation, Vestas will make no changes to the plans for the turbine’s release for sale, marketing and production.