As much as wind turbines are great for producing clean energy, disposing of them when the time comes can be challenging. Researchers in China have hit upon a clever way to use discarded blades to build long-lasting roads – a method that could come in handy as we erect and decommission more turbines over time.
While most parts from old wind turbines can be recycled or reused, including the shell, nacelle, and metallic internal components, the long blades are typically made from fiberglass. That's especially true of blades that are reaching the end of their lifespan now, after having been in use for the last couple of decades.
In 2023, the National Renewable Energy Laboratory (NREL) in Denver, Colorado, estimated that between 3,000 and 9,000 turbine blades will be retired each year for the next 5 years in the US alone; that figure would then increase to between 10,000 and 20,000 until 2040.
Now consider how big the problem could be across Europe and China, which have the world's largest wind turbines. The largest turbine we know of, a 26-MW-generating behemoth set to be completed in China by Dongfang, has a blade diameter of 1,107 ft (310 m).
As turbines and wind farms with multiple turbines get bigger and bigger, both onshore and offshore, it'll be increasingly important to figure out what to do with all those blades. The properties that make these blades light, strong, and weather-resistant also make them hard to recycle.
A team from the Lanzhou Institute of Chemical Physics at the Chinese Academy of Sciences, has devised a process of crushing and chemically treating old blades so they can be combined into asphalt mixtures and cement concrete for constructing roads.
The researchers actually figured this out in 2024, and trialed it with a construction company last September. Five months after creating the asphalt mixture and laying a section of the Qingfu Highway in the northwest Chinese city of Lanzhou, the road has reportedly not developed any cracks or rutting.
This breakthrough joins a short list of applications – compiled by Chemical & Engineering News – where recycled blades can be useful:
- Global Fiberglass Solutions, headquartered in Kirkland, Washington, turns the blades into reinforced plastic pellets for manufacturing durable products like maintenance hole covers.
- Waste management giant Veolia shreds blades into small pieces that go in kilns to replace the coal, sand and clay required to make cement.
- Knoxville, Tennessee's Carbon Rivers recovers strong fibers from blades using a high-temperature process called pyrolysis; these can be used as-is or in the form of thermoplastic fabrics or pellets to make heavy-duty automotive parts.
There are also a number of efforts to make blades easier to repurpose or discard – from a quick-dissolving resin to manufacture them, to GE's recyclable thermoplastic, to a relatively inexpensive way to break down epoxy-based blades.
But while those are being tested and deployed worldwide over the next few decades, we'll still have this mounting issue of disposed blades to solve. The Lanzhou research team, meanwhile, will take on more projects to demonstrate its recycling technique, and establish it as a scalable way to repurpose old blades.
Source: Xinhua News
