Many countries are working towards reducing their CO2 emissions in a bid to become carbon neutral. Denmark is a world leader in wind energy. Last year it sourced almost half of its power from wind (47%) according to Energinet, the country’s grid operator. Offshore accounted for 18% and onshore 29%.
Complex wind turbine systems and components must be tested for different aspects including wind speed and direction, power performance, blade design and fatigue life, impact of diverse weather conditions and more.
IECRE, the IEC System for Certification to Standards Relating to Equipment for Use in Renewable Energy Applications, offers testing and certification which reassures investors, manufacturers and users of RE technologies that these are safe, secure, interoperable and function correctly wherever they are in the world. The system covers the wind, solar photovoltaic and marine energy sectors.
Rasmus Ladevig heads blade testing at the Danish facility, which has tested more than 50 blades. Ladevig led the process and explains how it went.
Why is it important to be an approved customer testing facility within the IECRE System?
The most important thing for us is to create trust with our customers. By having the IECRE approval our customers can be confident that we have carried out the tests according to IEC International Standards, whether we do the wind turbine blade testing at our own test centre or externally.
Our blades are sold with the IECRE approval. They are designed, manufactured and tested in compliance with internationally agreed content in the standards. Another important point is that IECRE third party certification includes not only an IECRE representative, but also another external testing laboratory representative to ensure objectivity throughout. Find out more in an interview with an IECRE Peer assessor for wind turbine blades. In addition to ensuring competent eyes on the theoretical part of testing, the peer review from other test centres provides an opportunity to strengthen the network between test centres. We have seen benefits through sharing of experience with e.g. health and safety aspects of blade testing.
How was the process to gain approval?
The process went very smoothly and professionally. The IECRE representative checked the structure of our quality management system and that we maintain our documents appropriately and the representative from the external testing laboratory from the Spanish National Renewable Energy Centre (CENER), did a deep dive to check that our more technical documentation was in place.
Can you describe the structural tests?
We test the structural integrity of the blade.
We do static tests, where we pull the blade once quite hard to simulate a wind gust hitting it. The test is performed outside using mobile cranes or inside using pulling stations. The blade is equipped with loading clamps and is tested in four directions by rotating the blade on the test foundation.
We do dynamic testing where we move the blade 2-4 million times up and down to see whether it fatigues. This is more to do with the operation of the turbine over its lifetime. It can take roughly nine to 12 months for the entire process from the time we receive the blade, to preparing it and running all the tests.