In the Netherlands, these written-off blades are incinerated by waste companies or recycled into low-grade materials. “The blades are made of fiberglass composite, a combination of fiberglass, carbon fiber and resin,” explains Ten Brinck. “That resin hardens and makes recycling very difficult.” The material, which is also used in aviation, for example, does not start a second life as a fiberglass composite, but is reused in concrete, for example.