Vestas is to improve quality standards in its manufacturing of prototype blades following an investigation into the detachment of a section of blade from a 3 MW wind turbine prototype installed in Lem, Denmark.

The Danish wind turbine manufacturer announced in early September that a 7-metre part of one blade broke away from the V112-3.0 MW prototype wind turbine during tests. No-one was hurt in the incident.

Vestas’ own forensic experts have concluded that human error during the manual manufacturing process of the blade was to blame for the blade detachment. The company says that it will in future ensure that “prototype quality meets higher demands”, but emphasised in a statement that “manually produced prototypes will … always involve a significant higher risk of failure than by automated production processes”.

The incident will not affect the company’s plans for the sale, marketing and production of the V112-3.0 turbine, which was released for sale in the middle of August 2010. Vestas says that the design of the turbine and blade has been certified according to global industry standards and that the failure of the prototype at Lem “cannot originate from a design flaw”.

The company has decided that its own investigation into the incident at Lem should be followed up by a third party external investigation.