Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Robust Blades and Foundations by Tilman Weber


Published on

With Larger Rotor Blades, New Strains Come into Play

External wear and tear such as erosions on the leading edge of the rotor blade, tension cracks as well as large-scale UV damage are common fatigue phenomena.
But with rotor blades being extended by up to 15 metres, new strains come into play, as Tilman Weber explains in his article "Robust Blades and Foundations" published in Erneuerbare Energien in February 2014. Read the full article for free here:

  • Be the first to comment

  • Be the first to like this

Robust Blades and Foundations by Tilman Weber

  1. 1. Special maintenance services keep propellers, foundations and even towers in working order. Their service is more important than ever. Robust Blades and Foundations TITELTHEMA 40 ERNEUERBARE ENERGIEN | Februar 2014
  2. 2. Three years ago, the German Wind Energy Association (BWE) discovered the theme of specialist maintenance for themselves. "Our working circle already existed years ago," says Stefan Brassel, spokesperson for the Association's own circle of experts AK Rotorblatt. It has been firmly established at BWE since 2010. Here experts on rotor blade repair develop criteria for "what measure of tolerance the thickness of an adhesive layer or a bridge position on the belt should have." These internal structural components give the rotor blade the necessary stability, but can also be potential breakage points. The BWE working circle spokesperson is also in charge of rotor blade maintenance at Deutsche Windtechnik in Bremen and is already familiar with the problem: Until now rotor blade manufacturers saw little need for sharing data. The BWE working circle has put together a damage catalogue with threshold values since then. It indicates what treatment would be most suitable for the respective severity of damage. Weak blades reduce the income The necessity for this self-help in spite of wind power development having been producing power in the gigawatts for many years is due to an erroneous development. Independent service providers and turbine manufacturer maintenance services have long competed over the maintenance of connecting rods, electronics or control systems. But the manufacturers often left the rotor blades or foundations to specialist firms. This is because the knowledge and climbing skills along turbine blades have little to do with the traditional machine- building know-how of standard maintenance services. Rotor blades and foundations therefore require specific teams, whose members often had to undergo expensive training. Yet, the main reason for part maintenance is not so much to avoid major accidents. "Often the base coating suffers damage through erosion," emphasises Brassel from the BWE working circle. New rotor blades often used to lack plastic films or double coatings, which are nowadays a requirement for large rotors. Because even small rotor weaknesses can cause large losses of revenue using cutting-edge wind farm technology, plant manufacturers have started to recognise the value of good foundations, towers and particularly rotor blade maintenance. "Turbine manufacturers had already started putting together maintenance teams for rotor blades three years ago," says a wind farm developer, who does not want to be named. According to interviews with randomly selected German project developers, ERNEUERBARE ENERGIEN attributes a long tradition to Enercon in this area. But Vestas and Nordex also count as pioneers. In 2008, the Spanish service provider GES took over the rotor blade repair company WKA Service Fehmarn. Nowadays, it maintains around 700 power plants every year using 130 technicians. The contractors are turbine manufacturers that hire GES as a subcontractor as part of their manufacturer service. Elsewhere in Europe, the GES maintenance section with 40 additional maintenance technicians is also booked by energy companies, stresses the CEO of the GES subsidiary in Germany, Arkin Pariltan. He adds that improved resins for gluing loose blade structures or optimisations in the protective layers against UV radiation from the sun increase quality of his company's service. Other specialist maintenance companies particularly define themselves with their staff's abseiling techniques to provide a service on those long, Good maintenance, good efficiency Rotor blades at wind energy farms have until now largely been maintained by specialist maintenance companies. Yet turbine manufacturers are beginning to employ crews to remove surface erosion or damage to the leading edge on rotor blades for more effective operation. Foto:Seilpartner ERNEUERBARE ENERGIEN | Februar 2014 41