As the wind energy industry struggles with the sticky issue of dealing with used turbine components, companies and researchers are coming up with ways to recycle those materials for a new life.
Turbine parts are replaced at various times during their operation, for regular upgrades and when blades are replaced at the end of their roughly 20-year lifespan. These replaced parts are creating a substantial waste issue for the industry, since they’re generally discarded. Now, new developments could offer opportunities to recycle both the blades and the rare earth minerals in turbine magnets.
Making Turbine Blades Recyclable
The wind industry has gone through some growing pains in recent years, but it is still expanding and new turbines continue to be installed. Blade size is increasing in size to improve efficiency, but turbines still have a lifespan of about 20 years, with the composite waste from retired blades expected to grow 20-fold over the next two decades. In 2044, the total volume is expected to peak at about 782,000 tonnes, says Bloomberg.
The wind energy industry is still on track to produce less composite waste than sectors like construction and electronics, and wind power is still by far a more environmentally friendly option than fossil fuels—despite the waste issue.
The tower and other components that make up about 90% of a turbine are made of steel and can be recycled, but not the turbine blades—aside from a small proportion that have been repurposed to make bridges or park benches.
What tends to happen is that used blades get chopped up and end up in landfills because the carbon fibre composite they are made from contains thermoset resin, a polymer that undergoes an irreversible curing process while hardening. The material allows companies to maintain blade strength and light weight while building them longer, but it also means the blades can’t be recycled later.
“People criticized wind as ‘trash energy’ because of the unrecyclable blades,” said Robert Tsai, whose company, Swancor Holding, is trying to develop recyclable products that can replace the non-recyclable materials blades currently use.
“I wasn’t convinced and invested in our R&D efforts, and after several years, we were able to make it,” he added. “We changed the material.”
Swancor aims to improve blade recyclability with a new resin it calls EzCiclo, which Tsai says has the same physical properties as the resins used today except that the fibres can be reused after being dissolved in a heated vat of a specialized liquid the company calls CleaVER. Tsai anticipates that developers will opt for the 10% to 15% higher cost compared to traditional resin to meet their sustainability goals. But some experts have their doubts.
“As a developer, you can’t afford to have blades failing at a rate beyond which you would normally model within your predictive maintenance schedules, so there may be reluctance to adopt this equipment until there are a good few sites operational and clear evidence of their long-term durability,” said Paul Jensen, a lecturer in business, environment, and development at the University of Leeds.
Jensen told Bloomberg that other questions about the quality of the recycled materials and who will provide the recycling services leave “lots of if, buts, and maybes” about whether the new blades will take off.
Rare Earth Minerals in Turbine Magnets
To improve performance during their lifespan, wind turbines undergo continuous “repowering”, where various parts are swapped out or upgraded. Among those parts are magnets that contain rare earth elements like neodymium and dysprosium. Even though they’re in high demand for use in smart phones, laptops, and electric car motors, the elements from turbine magnets are simply disposed of and lost.
“Right now, to our understanding, essentially no rare earth elements from wind are recycled,” Tyler Christoffel, technology manager in the United States Department of Energy’s (DOE) Wind Energy Technologies Office, told Grist.
Failing to recycle the magnets raises environmental concerns, especially as it means increased mining for rare earth elements to meet demand powered by the energy transition.
Concerned about future access to rare earth element supply chains, DOE is offering funding prizes for “[developing] a cost-effective and sustainable recycling industry for key wind turbine materials not currently recycled commercially.” The department recently announced US$5.1 million distributed to 20 winners of its Wind Turbine Materials Recycling Prize.
The quest to recycle rare earths from turbine magnets has also been attracting market interest, including from Kingston, Ontario-based advanced metals recycler Cyclic Materials. The company recently expanded its operations to include feedstock from wind turbine generators containing permanent magnets, as well as from magnetic resonance imaging (MRI) machines.
“Manufacturers, developers, and stakeholders across metals supply chains must recognize the importance of creating a circular supply chain—not only to reduce dependence on offshore sources and increase resilience, but to slash the environmental impact of the industry,” said, CEO and co-founder Ahmad Ghahreman.
It appears as though the blades could be used as wind sails for ships, with slight modifications of course. Just a thought.