Sustainable wind energy through steel rotor blades
Sustainable energy supply is one of the most urgent challenges of our time. In its “Osterpaket”, the German government set a target of covering 80% of gross electricity demand from renewable energies by 2030. A key component in achieving this goal is wind energy, especially onshore. The “Wind-an-Land-Gesetz“ stipulates that onshore wind energy is to be expanded by 10 GW per year. However, the expansion has recently stalled, mainly due to a lack of acceptance by the local population and the lack of recycling facilities for disused wind turbines.
A promising solution to these problems is offered by the "SteelBlade" project. The aim of the project is to develop, design and validate an onshore rotor blade for wind turbines that is optimized for steel. The use of steel enables increased sustainability and environmental relief, as steel is up to 90% recyclable. In addition, steel construction opens up new perspectives not only in terms of recyclability.
Another obstacle with large rotor blades is transport, which presents difficulties due to their size and shape. Currently, onshore, limited by the transport of rotor blades by road, no significantly larger turbines can be installed, although this would make sense from an economic point of view. Segmentation of rotor blades can solve this problem. However, existing approaches to segmenting conventional rotor blades made of fiberglass and carbon fiber-reinforced plastic are reaching their limits. Steel is a very easy material to join, which makes it possible to develop and apply new segmentation concepts for rotor blades without compromising the stiffness of the blades.
In addition to solving the problem of transporting large turbines, segmented steel rotor blades offer other advantages. They can be transported more cheaply and easily, which facilitates the development of new locations for large wind turbines. In addition, the material steel increases the erosion resistance of the blade, which allows higher rotational speeds at the blade tips and thus lower torques with the same power output; this would relieve the drive train.
The SteelBlade project uses lightweight construction and optimization methods from the aerospace industry to ensure efficient use of steel as a rotor blade material. Particular emphasis is placed on the design of the inner structure and the aerodynamic outer blade envelope. The overall weight of the steel rotor blades is to be on a par with conventional rotor blades made of fiberglass composites.
The project will demonstrate the technical, economic and sustainable feasibility of the steel rotor blades.