rethink*rotor, the repurpose of rotor blades in the construction sector promotes the circular economy that works across industries, which not only enables significant CO2 reductions by keeping the giant blades in the anthroposphere, but also shows a way out of the recycling dilemma. Thanks to the aesthetic potential and material properties such as durability, corrosion resistance, lightness and stability, added value is gained for the construction industry.

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The European Union's goal, as set out in the "European Green Deal", to reduce net emissions of greenhouse gases to zero by 2050, or to offset all unavoidable emissions with suitable processes and thus become the first continent to become climate-neutral, requires the transformation of the economy to circular systems (Circular Economy). The European fiber composite industry is facing major challenges in this context. On the one hand, the demand for lightweight materials in energy-intensive value chains such as the wind energy industry will increase; on the other hand, fiber composites have been so far difficult to reuse or recycle because the available technologies such as high-temperature pyrolysis or shredding (for use as a filler) are either not environmentally friendly or economically unattractive. In addition, it is forecast that from 2025 onwards, around 80,000 tons of material will be produced annually from end-of-life composite components - in Germany alone, around 7,500 discarded rotor blades are removed from wind turbines every year. But what happens to the discarded, in some cases over 80 m long, custom-made epoxy resin-bonded fiber-reinforced plastics (FRP) after their approx. 20 years of use in the wind farm? Some are therefore shredded after dismantling and metal residues contained therein are separated. The remaining waste is thermally recycled as fuel and sand substitute in the cement industry or incinerated in small quantities in conventional waste incineration plants. This form of thermal recycling is not residue-free, neither CO₂-neutral, nor sustainable.

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Upcycling: the aesthetic potential of the blades, their durability, corrosion resistance, lightness and stability are an added value for the construction industry.

New life cycle: the reuse of rotor blades reduces the consumption of raw materials and energy and the amount of waste generated.

rethink*rotor provides high-quality yet simple solutions for the complex task of giving disused rotor blades a second life in the construction sector and integrating them into the architecture of buildings.

The complex geometry of the rotor blades and their material properties, such as durability, combined with low weight and high rigidity, offer the way out of the recycling dilemma. The shapeliness of the components and the efficiency of the composite material can be "profitably" exploited in new applications. The construction industry, with its large material consumption, is therefore particularly predestined for the use of end-of-life (EoL) components. The challenge, which results from the complexity and a long-lasting use of the parts once produced, whether these are rotor blades or parts of a building, illustrates the urgency of solving the individual critical aspects. Without this, the vision of the building turnaround and the sustainable built world is just an illusion.

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An important aspect when deciding where to use the discarded rotor blades is the proximity to the site of the wind farm that is to be dismantled. This guarantees short transport distances. For this reason, the applications are divided into onshore and offshore applications.

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Using EoL wind power rotor blades as an example, rethink*rotor demonstrates that it is possible to create a closed loop of materials and further use EoL rotor blades in construction and give the process prominent visibility. The whole chain from the condition assessment of the EoL rotor blades: the logistics and the reprocessing, the planning of the recycling, the statics and implementation, must and will be profitably considered taking advantage of their aesthetic potentials. The knowledge and gray energy bound in each wind rotor blade will definitely be lost if it is not reused. With its project ideas, rethink*rotor aims to link a cross-sector repurpose of the blades, creative energy, new technologies and sustainability goals.