WindEurope estimates 14,000 turbine blades could be decommissioned in Europe by 2023, increasing the need for a broader range of recycling options.
Established recycling practices exist for most wind turbine components, such as the foundation, tower, and parts of the nacelle. Between 85% and 90% of a wind turbine’s total mass can be recycled today.
But recycling blades is difficult because they are made from complex composite materials — to allow for a lighter, more durable design — and require special processes for recycling.
The research was carried out by industry bodies WindEurope, the European Chemical Industry Council (Cefic), and the European Composites Industry Associates (EUCIA).
To date, the number of turbines being recycled has been quite low. This means that the market for recycling wind turbine blades is niche and operators are not economically incentivised to cater to the wind-power industry, WindEurope explained.
However, it expects the market to pick up beyond 2021 as more projects reach the end of their operational life.
In Germany, where the bulk of decommissioning will take place in the early 2020s, recycling companies processing turbine blades are confident they can handle the increased throughput and are planning to expand facilities and run them in shifts, a WindEurope spokesman told Windpower Monthly.
The main technology available for blade recycling is cement co-processing, whereby glass fibres and mineral components are reused in cement. This process is fueled by the burning of plastic blade elements in energy-from-waste plants.
Cement co-processing is currently commercially available for processing large volumes of waste, the three industry bodies found — but not in all European countries. It should, therefore, be deployed more widely to deal with growing waste, they concluded.
The process is highly efficient, fast and scalable. However, blade composite fibres lose their original physical shape during cement co-processing, so the end-product cannot be used in other composites applications, they noted.
The authors also suggested that more research and innovation funding is needed for other recycling technologies — including mechanical recycling, solvolysis (recycling based on chemical reactions) and pyrolysis (decomposition caused by high temperatures).
These technologies currently require high running costs, and have other individual weaknesses.
Mechanical grinding is only available at a small-scale, solvolysis is energy-intensive, and fibres subjected to pyrolysis lose their strength due to the high temperature needed.
WindEurope, Cefic, and EUCIA concluded a better understanding of the environmental impacts associated with the choice of blade materials during design and with different waste treatments at the end-of-life is needed.
They argued that composite recycling is a cross-sector challenge, which requires active engagement from all composite-using sectors and authorities to find cost-effective solutions and strong European value chains.