Randers, Denmark — Danish wind turbine manufacturer Vestas says that human error in the manufacturing process was behind the 8 September detachment of a blade piece from one of its 3.0 MW V-112 model prototype turbines sited in Lem, Denmark.
“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,” said the company.
The blade was one of those built for the first three prototypes of the model to be manufactured and had not been subjected to Vestas’ normal verification and reliability testing programme but, said the company, had been through a comprehensive test programme which validated the design – including that of the blade.
“The [turbine and blade] design has thus been certified according to global industry standards, and therefore Vestas’ conclusion is that the failure cannot originate from a design flaw,” said Monday’s statement.
Following the incident the company said it would ensure the quality of its prototypes would in the future meet higher demands than for this particular model.
However, it went on to say manually produced prototypes would always involve a higher risk of failure than those created in an automatic production process.
“To make sure there is no doubt about the root cause [of the detachment], the management of Vestas Technology R&D has decided that Vestas’ internal investigation will be followed up by a third party, expert investigation,” continued the statement.
The result of the third party investigation will be communicated to the stock exchange as soon as it concluded, added the company.
Further the company said: “It is important to emphasise that when the V112 turbine is put into serial production, this kind of failure will not be possible in [the] Vestas’ automated manufacturing process.”
Concluding, it said that on the basis of its investigation it would make no change to the plans for the turbine’s release for sale, marketing and production.
The new turbine was released for sale in mid-August and at the beginning of August the company said it had won an order for 120 of the turbines to be supplied to Australia’s largest wind power project – the Macarthur Wind Farm in Victoria – which is being jointly developed by AGL Energy and Meridien Energy.