Keywords: Wooden blade; Recycling
Newly established German Voodin Blade Technology GmbH contacted WINDnovation with the idea to make rotor blades for the next generation wind turbines mainly from wood. While it sounded strange in the beginning, the engineers looked a little deeper and found charming aspects:
- Recycling, one of the biggest headaches of glass or carbon fiber reinforced rotor blades, will not be an issue anymore.
- The relative stiffness (E-modulus/density) of the selected wood is nearly identical to UD glass fiber.
- The structural damping properties are much better than for composites.
- The raw material is very available at a low price.
- The final surface will be prepared by positive milling, so no moulds will be needed anymore. This is of special interest for the production of replacement blades where in many times production moulds are simply not available anymore.
For demonstrating the technology, currently a 20m blade is under development, which will run through all production steps, which are expected to be suitable for manufacturing of very large blades in the Multi-MW class. According to the plans, a fully sensor equipped first set will be installed in summer 2021 in Germany and be operated and closely monitored for at least one year.
It shall be mentioned that not all questions with regard to rotor blades made from wood are solved:
- Selection and application of the surface coating to make the blades last 20 or 25 years will need some research.
- To protect the leading edges from erosion will need same research and potentially tests.
- According to the current estimate the blades will be some 20% heavier than their glass fiber equivalent, some of the load increase resulting from the mass might be compensated by the higher structural damping, this is subject to further investigations.
Voodin Blade Technology and WINDnovation will closely cooperate on finding good solutions to make the wooden blade technology mature. We will to publish updates every now and then talking about the latest achievements!