Recycling Challenge Rotor Blades

Rotor blades are challenging to recycle due to the composite materials used in their production. Today 2.5 million tonnes of composite material are in use in the wind energy sector globally.  Recycling old blades is a top priority for the wind industry, especially as a significant proportion of the installed EU wind fleet will come to the end of its lifetime between 2020 and 2030.

Up to 52,000 tonnes of composite waste from rotor blades can be expected until 2030 every year, Marylise Schmid, analyst for environment and planning at WindEurope, pointed out: high time to find solutions for a closed product loop. Foremost among these is a call for a European landfill ban on decommissioned blades by 2025. This means the wind industry commits to re-using, recycling or recovering 100% of decommissioned blades by 2025 and establishing a Europe-wide cross-sectorial platform to share good practices.

Real-time walk through a plant recycling GRP

While various technologies exist to recycle blades, and an increasing number of companies offer composite recycling services, most solutions are not yet widely available or cost-competitive. The main technology and economically viable way for recycling composite waste today is through cement co-processing, allowing processing of large volumes. Cement co-processing allows 100 percent recovery for material recycling (glass acts as a substitute for sand) and thermal recovery (resins act as a substitute for coal), as Mika Lange, Head of waste management at neowa gmbH, explained. A “real-time walk through the plant recycling GRP” gave insight into the mechanical treatment and homogenization of GRP waste to create a substitute for the cement industry.   

Closing the loop

Tanja Freiburg, managing director at Geocycle GmbH, explained how to close the loop from dismantling wind towers and rotor blades to cement delivery for foundations and towers. The method of co-processing enables the simultaneous recovery of energy and raw material from composite material. It is an applied example for the circular economy in a nutshell: from dismantling and pre-shredding via further processing steps to energy and material recovery in cement kilns. The produced cement is then used for new towers and foundations.

Developing viable, large-scale solutions that accelerate the transition to a circular economy is a composites sector challenge with sustainable materials at its core, Katelyn Huber, product life cycle leader at LM Windpower, pointed out. Developing new materials requires long-term investment in R&I and close collaboration with suppliers. Cross-sector partnerships are needed to commercialize mature composite recycling technologies. The Zebra (Zero wastE Blade Research) project for a circular economy linking the whole value chain is a step in this direction.

In the final overview Steffen Czichon, head of the rotor blades department at Fraunhofer Institute for wind energy systems, explained the pros and cons of the different technologies for recycling rotor blades. In the short and medium term co-processing is a proven recycling path. However, pyrolysis is also considered a viable option. The success of recycling technologies will ultimately not be determined by technological progress alone but also by economic and legal boundaries. When considering the future, we will have to answer the question of how to build blades that are easier to recycle.