Due to increasing international competition, manufacturers of wind turbines are under pressure when it comes to costs. The certification process in particular can offer substantial savings potential. Detailed knowledge about certification processes and about their influence on each other can be used as a benefit.

For market access of wind turbines it is important that component certificates issued by diverse certification bodies are recognized by the body which carries out type certification.

"The component certificate can then be easily integrated into type certification. No additional detailed reviews of the components must be carried out, "said Benjamin Jendrosch, Product Manager Wind Energy at TUV Rheinland on the occasion of the 5th NRW Wind Energy Day in Dusseldorf.

Jendrosch added, "In practice, this leads to a significant reduction in cost for type certification."

Partners who apply the method described below enjoy many advantages: Manufacturers benefit from individual components having been inspected and certified by an independent and accredited body in the basic manufacturing criteria and specification features prior to the start of any wind energy project. As a result, the process of type certification becomes faster and cheaper.

Components manufacturers, in turn, benefit from significantly improved market opportunities. Furthermore, the confidential treatment of documents regarding new developments is guaranteed as such documents are made available exclusively to the certifier.

Before installation, wind turbines undergo various certification processes. Type and components certifications are the most important. In the type certification process, the design of the complete wind turbine and all included components such as towers, blades and gearboxes are inspected. Components certification examines the quality of individual principal components based on predefined load assumptions.

This includes the inspection of design calculations, manufacturing facilities and processes and prototype testing. The certifying body performing type certification verifies whether the evaluation of components is sufficient for recognition. "All documents necessary for components certification should be made available by the applicant," recommends Jendrosch. Mandated requirements to achieve the appropriate recognition of certificates of components must be met.

Certifying bodies issuing components certification should be accredited by a member of the multilateral agreement of the EA, IAF and ILAC. In Germany, for example, it is the German Accreditation Body (DAkkS GmbH) which fulfills these prerequisites. Furthermore, all components certification documentation must be fully submitted to the certifying body performing type certification.

Finally the specification of the interfaces between each component and the rest of the wind turbine must be clearly defined. If all of these requirements are fulfilled, awarded components certification can be simply integrated into the type certification, shortening the overall certification process.