In permanent rotation: recycling wind turbines
The first generation of wind turbines is reaching the end of its lifespan, prompting the renewables energy industry to consider recycling. Huw Morris reports on circular economy potential in this area
Once it was on the horizon. Then it became a growing problem that threatened to cause a crisis. Now, finally, Chris Hill thinks the UK is on the cusp of a major breakthrough. At stake is not only a significant step in the transition to net zero, but also a spin-off circular economy, packed with business opportunities and thousands of jobs.
Hill, operational performance director at ORE Catapult, has been grappling with one of the thorniest problems facing wind energy. Wind turbines have an average lifespan of 25 years – and many of the first generation are now coming to the end of their lives. While up to 90% of a turbine is recyclable, their blades, which are made from composites of resins and fibres, remain a huge obstacle.
Now the Energy Transition Alliance (ETA), a partnership between ORE Catapult and the Net Zero Technology Centre, with input from the National Composites Centre and the University of Leeds, has investigated alternatives to landfill and incineration. It believes up to 14 mechanical, thermal, chemical and reprocessing technologies show promise for recycling (see Recycling technologies under investigation, right). However, these will need further development, particularly around their environmental impact, energy use and cost efficiency.
Hill acknowledges the technologies need “intensified investment” across many sectors before they can be deployed at scale. Earlier efforts to recycle blades have been hampered by a failure to match recovered materials to the needs of the supply chain and end-products, he admits. “Engagement with the UK supply chain is the first step for us: recycling is only of benefit when the recovered materials have saleable end-products that prevent deployment of virgin materials.
“Wind industry manufacturers and operators are beginning to set ambitious targets for achieving zero-waste turbines within the next 20 years. There is also a hotbed of research into lifetime extension of turbines, pushing towards 40-years, as well as exploring alternative materials. Recycling these first-generation blades is the first step in achieving zero waste.”
Opportunities to be had
The ETA estimates the global offshore wind industry will need to decommission 85GW of capacity, including 325,000 blades, by mid-century. Recycling all major components could generate 5,000 UK offshore wind sector jobs. However, a more advanced circular model, involving remanufacture and refurbishment of turbines and components, would extend this to 20,000 extra jobs – this would amount to an increase of a third on the UK government’s current 2030 target.
Recycling turbines is also an opportunity for onshore wind, according to Zero Waste Scotland. Around 5,500 wind turbines will need to be decommissioned in Scotland by 2050, potentially generating 1.25m–1.4m tonnes of materials.
Ferrous metals such as steel and iron make up the biggest cohort of waste and are currently exported for recycling. More than 60,000 tonnes of fibreglass and 90,000 tonnes of resin and balsa materials will also be produced, all of which are landfilled. Zero Waste Scotland chief executive Iain Guillard sees a “fantastic opportunity” to embed circular solutions into the resource management of these materials.
“Decommissioning and refurbishment of wind turbines will release valuable metals like steel and iron, and component parts like gear mechanisms, into circulation, thereby unlocking the potential for economic gain. However, as these materials are currently exported for recycling, the Scottish economy is losing the value of these resources.
“Onshore wind decommissioning is fast becoming a practical problem for many European countries. To date, across Europe, 34,000 turbines are known to be 15 years or older. There will be a big market for decommissioning onshore wind farms over the next decade and, if we act now, Scotland is in a prime position to provide a circular solution and establish competitive advantage.”
Recycling technologies under investigation
Mechanical
- Grinding
- Cement kiln co-processing
Thermal
- Pyrolysis – decomposing materials at
- high temperatures in an inert atmosphere
- Fluidised bed pyrolysis
- Microwave assisted pyrolysis
- Steam pyrolysis
Chemical
- Solvolysis – using solvents to recover chemical products and high-grade
- carbon fibre
- High temperature and pressure solvolysis
- Low temperature and pressure solvolysis
- Electrochemical
Reprocessing
- Milled fibre (post-grinding)
- Chopped fibre (post-pyrolysis solvolysis)
- Pellets
- Non-woven mat
- Component re-use.
Huw Morris is a freelance journalist.