Periodic Quality Check, useful and necessary

Column by Maarten Timmerman, director of BLIX Consultancy BV

Lately reports of loose wind turbine components reached the media. In a short period, problems with the blades of turbines at Medemblik, Andijk and Tzummarum arose independently of each other. In response to these reports, TU Delft professor Van Bussel proposed to introduce a mandatory independent periodic quality check every two years for turbines that are older than twelve years. BLIX put a similar idea on the market a year ago as the Eyewind periodic quality check concept.

One should not image what can happen when someone is nearby at the time a blade gets loose. Luckily the turbines in Medemblik and Andijk were not near any buildings, but the loose blade in Tzummarum went through the roof of a shed and that could have had serious consequences. The legislation in the Netherlands is very strict and the permits for building a wind turbine now enforces that the probability of accidents caused by a loose blade is less than one in a million. The chance of being hit by a falling tree is considerably larger.

The lifetime of a wind turbine is twenty years. The turbines with the loosening blades were older. One would expect that these turbines would have been replaced or removed, but there is nothing wrong with operating them longer provided they are properly maintained. This is where it sometimes goes wrong. In my experience, there is often a gap in knowledge between the turbine owner and the party performing maintenance on the wind turbine. Because the interests of both parties do not always align, it can happen that wind turbines perform suboptimal without the owner being aware of it.

Especially given our experience, BLIX is a strong supporter of the idea of Van Bussel to introduce a periodic quality check for wind turbines. That is why BLIX started the Eyewind initiative in cooperation with Eyewings last year. Under the brand name Eyewind, we perform periodic quality checks with the purpose to assess damages that may adversely affect the safety and reliability. The big difference with the proposal of Van Bussel is that Eyewind starts these checks during the building of the wind turbine.

The independent inspections and assessments of Eyewind are focused on the optimization of the production by regularly inspecting and monitoring wind turbines. Thereby detecting damages at an early stage or even preventing damage. The safety of the wind turbine is automatically guaranteed with these inspections. Damage to the reputation of the turbine owner is prevented. The benefits of the periodic quality checks will eventually outweigh the costs of introducing them. The knife cuts both ways.

I therefore applaud the initiative of Van Bussel.