DNV Introduces New Special Level Wind Turbine Type Certification System (Denmark)


In order to enhance flexibility and speed with regards to type certification, DNV is introducing a new ‘Special Level’ Type Certificate for wind turbines. It differs with respect to the Type Certificate according to IEC 61400-22 in that blade fatigue testing will not be required.

The Special Level Type Certification will provide DNV’s clients with an additional approach to help increase competitiveness in the rapidly-developing wind energy market. DNV still strongly recommends the entire IEC 61400-22 Type Certification system is completed as part of a blade development process, as fatigue testing of blades reduces the wind turbine’s technical and commercial risks. However, the Special Level Type Certificate can provide a fast and flexible path to the market, with reduced time and expense, with the option to transition to a full IEC Type Certificate at a later time.

Introducing more flexibility in the scope of certificates allows for verification levels consistent with the demands of different market, financial, and regulatory requirements. The scope of the Special Level Type Certificate, which will not include blade fatigue testing, will be similar to products offered by other certification bodies. Blade fatigue testing, which is part of IEC 61400-22 will still be required for DNV’s other type certification products.

“This step is in reaction to requests from our clients,” says Claus Christensen, Head of Department for DNV’s wind certification center in Copenhagen, “We expect that most of our clients will still conduct blade fatigue testing but that some of our clients perhaps will do this on a different time scale than the certification process. It’s important that we be responsive to the demands of the market, while at the same time maintaining our commitment to quality, independence, and technical competence.”

DNV has been active in developing standards, specifications and guidelines for wind turbine structures and components since 1989. The standards integrate decades of experience from the offshore industry with DNV’s in-depth wind turbine knowledge gained from type certification of large megawatt turbines. In addition, DNV takes a leading role in developing and revising international standards through active involvement on a number of IEC committees and European and national standards bodies.


Source: DNV, May 25, 2011