What can be recycled on a wind turbine and what can't?
If a wind turbine needs to be dismantled, there is above all a question: What happens to the old windmill? This issue is currently playing a major role, as more and more wind turbines will soon reach the end of their subsidised service life.
Most of this question is quite easy to answer: about 90 percentto be precise. This is the proportion of materials in a wind turbine that can be easily recycled and reused, whether for further wind power projects or in other industries. These 90 percent are primarily wind turbine towers: It consists primarily of a concrete base fitted with a steel cap. Both materials can be easily recycled, for example, the concrete is often used in split, i.e. crumbled form for road construction. And if the mild steel does not show any signs of wear or rust, it can also be used for further construction projects without problems.
It only becomes a real problem for the remaining around 10 percent of the entire wind turbine: the rotor blades. They consist of a complex material mix of balsa wood and plastics, which are reinforced with glass or carbon fibres. These materials ensure stability and weather resistance during operation, so that the blades can withstand all weather conditions even at speeds of up to 400 km/h.
The stability this material mix brings ultimately creates difficulties in the recycling process: For recycling the rotor blades, the glass and carbon fibres would have to be separated from the plastic again. So far, however, there are only a few and very elaborate and expensive methods for this. For many operators, such procedures are therefore often not the first choice.
This is why the recycling problem has often been ignored so far: Dismantled blades in some cases remained unused on fields for years. In many other cases, the glass fibre-reinforced rotor blades in particular are often used as replacement fuel or deposited abroad. Solutions with which Peter Kurth, President of the BDE Waste Management Association, is not at all satisfied. He considers these forms of recycling an annoying waste of resources: “The recyclables have to be returned to the cycle instead of simply burning them,” says Kurth.
An overview study by the German Federal Environment Agency forecasts a rotor blade waste volume of up to 50,000 tonnes per year for the 2030s. Accordingly, the rotor blades of wind turbines generate a large amount of waste, which should not actually be any.
Organisations such as the Waste Management Association or the German Wind Energy Association are therefore actively working to build wind turbines that can be better recycled and returned to the recyclable material cycle, not least against the backdrop of an ever-increasing awareness of sustainability. After all, sustainable wind energy production also contributes to this.
