WIND TURBINE TYPE CERTIFICATION

In today’s energy market, it is vital for wind turbine manufacturers like LEITWIND to be able to convince customers of the capabilities of their new designs. The customer needs as much assurance as possible that the design meets the required specifications.
But what is type certification? It is an evaluation by a third party — an accredited certification body — which certifies that the wind turbine manufacturer sells products that meet reference standards and regulations.

TÜV Süd, TÜV Nord, TÜV Rheinland and DNVGL are just a few of the organizations authorized to issue type certificates. The types are linked mainly to the sectoral standards IEC 61400 (currently being replaced by the IECRE), GL2010 (Germanischer Lloyd) and other national standards such as DlBt (towers and foundations certification in Germany).

Taking IEC 61400-22 type certification as an example, the purpose can be:
  • Prototype certification: evaluation of a new wind turbine design.
  • Type certification: evaluation of a wind turbine design and a serial production process. 

In general, IEC 61400-22 type certification has numerous advantages such as giving a new turbine model greater credibility and providing easier access to finance and new markets. A type certificate gives evidence about its manufacturability, installability and operability.

Consequently, the type certification process is usually one of the most important, though it is often based on prototype certification carried out in a previous phase.

There are several stages to type certification, some of them mandatory and some optional.

The mandatory stages are:
  • Design Basis Evaluation: this stage checks that standards, methodologies, assumptions, etc. comply with IEC 61400-22
  • Design Evaluation: in this stage the certification body checks in detail that the design complies with IEC 61400-22, for example the control of design loads, structural checks, manuals, etc.
  • Manufacturing Evaluation: this is a check of the component manufacturers’ quality systems; inspections of their production are carried out.
  • Type Testing: this is a set of performance tests carried out at specialist laboratories and on a prototype turbine, to check that they comply with the design. Prototypes of the blade and gearbox, and loads and energy performance, are also tested.
  • Final Evaluation: the evaluation results are provided in this stage. 

Type certification is valid for 5 years on average and can be renewed by the certification body once any design modifications and any problems with installed turbines and the remediation of these problems have been evaluated.