Rotor blades are robust, which makes recycling difficult. So far, it has hardly been possible to do more than store them in landfills. A modern rotor blade measures 70 meters in length, up to 90 meters for offshore systems, and weighs about 25 tons. The size alone makes transporting a rotor blade difficult. Special transport is usually required for this. The following processing is difficult due to the composition of the leaf: The plastics reinforced with glass fibers are ultimately designed to withstand the most adverse weather from storms to lightning strikes.
Rotor blades in landfills are not a huge environmental risk
The delicate beginnings are so far not enough to master the mass of systems that will be scrapped in the coming years. However, the rotor blades are waste that is often left in the environment or even buried, but not a major environmental risk. They do not release large amounts of dangerous pollutants into the environment. They just lie there.
The blades are cut on the ground with a band saw or, a water jet lance to recover and recycle the balsa wood contained in the rotor blades. Up to 15 cubic meters of wood can be extracted from a rotor blade. To do so, the ten cut blade pieces are crushed in a shredding machine. These are mobile machines that can be set up at the desired location. Further separation takes place through an impact mill. can be reused for various purposes.
One way to recycle the fiberglass composite would be thermal recovery by incineration, where the plastic component burns and the glass fibers are leftover. To do so they are shredded so that they can be used as substitute fuel by the cement industry. Cement rotary kilns operate at temperatures of 1200 – 1250 °C. The ash that remains consists mainly of silicon and can be added to the cement with no problem as a raw sand substitute.
If the above-mentioned recycling process becomes established across industries, a zero-waste concept would be created. It is important to find such sustainable solutions, as a large number of existing and newly built wind power plants require an increasing number of rotor blades which, after their service life, either have to be disposed of on landfills or recycled.