Designed to last for decades and to withstand harsh weather conditions such as rain, hail, snow, hurricanes and tornadoes, wind turbine blades are mostly made of composite materials, known as thermosets. Strong and light at the same time, they are composed of fibres and epoxy resin, which is essential to hold the blade elements together and preserve its structural integrity. The only problem - and a big one - is that it is very difficult to break down these elements for reuse and recycling.
This is why, until now wind turbine blades either end up being buried in landfills or are sometimes crushed and burnt in cement plants. However, according to WindEurope, the voice of the wind industry that promotes wind energy across Europe, around 25,000 tonnes of blades will be dismantled and out of use by 2025. The issue of recycling is now of paramount importance.
Using end-of-life blades as raw material for new ones
Rather than embarking on a new approach to the design and manufacture of recyclable blades, Vestas has focused on their end-of-life.
Together with the University of Aarhus, the Danish Technological Institute (DTI) and Olin, partners in the Danish research project CETEC (Circular Economy for Thermosets Epoxy Composites), Vestas has developed a chemical process for breaking down epoxy resin and returning it to a virgin material with identical properties. This technology would allow old epoxy-based blades and those currently in use at wind farms to be used as a source of raw material and to produce new ones. This new, undisclosed solution would also make it possible to use all epoxy resin composite materials as feedstock for a wider circular economy, which could encompass other industries beyond the wind sector.
A circular solution to end the disposal of wind turbine blades.
After two pilot years, Vestas has now entered the development phase of its process. Supported by Stena Recycling, the Nordic recycling leader, and Olin, the global epoxy manufacturer, the company will now focus on scaling up the new chemical disassembly process into a commercial solution. Once mature, this solution will mark the beginning of a circular economy for all existing and future epoxy-based turbine blades.