Laura Paddison
Sun May 28, 2023
Synopsis
Wind turbine blades, made of fiberglass and epoxy resin, pose a recycling challenge due to their durability. Danish wind company Vestas claims to have found a solution using a chemical process to break down the blades into reusable materials. This breakthrough could address the growing issue of blade waste, which is projected to reach millions of tons globally by 2050. Other companies are also exploring recycling methods, including grinding blades for use in cement production and using pyrolysis to produce glass fibers. Researchers are working on developing blades with recyclable materials. Vestas' discovery shows promise in recovering materials from current blades without harmful chemicals and high energy consumption. Scaling up the process remains a challenge, but it marks a positive step in addressing the issue.
Wind turbines are built to last. Their tall bodies are topped with long fiberglass blades, some more than half a football field in length, made to withstand the harshest, windiest conditions.
But this sturdiness brings a big problem: What to do with these blades when they reach the end of their lives.
While about 90% of turbines are easily recyclable, their blades are not. They are made from fiberglass bound together with epoxy resin, a material so strong it is incredibly difficult and expensive to break down. Most blades end their lives in landfill or are incinerated.
It’s a problem that’s vexed the wind energy industry and provided fodder for those who seek to discredit wind power.
But in February, Danish wind company Vestas said it had cracked the problem.
It announced a “breakthrough solution” that would allow wind turbine blades to be recycled without needing to change their design or materials.
The company said the “newly discovered chemical technology” breaks down old blades in a liquid to produce high quality materials, which can eventually be used to make new blades, as well as components in other industries.
Claire Barlow, a sustainability and materials engineer at Cambridge University, told CNN that if this kind of technology can be scaled up, it “could be a game changer.”
In 2019, an image from Casper Regional Landfill in Wyoming showing piles of long, white blades waiting to be buried went viral, prompting criticism of the environmental credentials of wind power.
Wind energy has been growing at a fast pace. It is the world’s leading renewable energy technology behind hydropower, and plays a vital role in helping countries move away from fossil fuel energy, which pumps out planet-heating pollution.
But as the first generation of wind turbines start to reach the end of their service lives, while others are replaced early to make way for newer technology – including longer turbine blades that can sweep more wind and generate more energy – the question of what to do with their huge blades becomes more pressing.
Blade waste is projected to reach 2.2 million tons in the US by 2050. Globally, the figure could be around 43 million tons by 2050.
There are few easy ways to deal with it.
Current options are not only wasteful but have environmental drawbacks. Incineration brings pollution and, while wind companies say there is no toxicity issue with landfilling blades, Barlow said that’s not yet totally clear.
“That’s not as benign as you might think,” she said.
Turbine blade materials make recycling hard and costly. The epoxy resins used to make turbine blades are called “thermosets.”
“If you heat them up, they don’t change their properties until they just burn,” Barlow said. “You can’t just scrunch them up and recycle the material into something easily reusable.”
That’s why Vestas hopes its new technology could hold real promise.
“This has been the key sustainability challenge in the industry. And so we’re of course very excited to have found a solution,” Lisa Ekstrand, the head of sustainability at Vestas, told CNN.
The process, which the company has been working on in partnership with Aarhus University, the Danish Technological Institute and US-based epoxy company Olin, uses a liquid chemical solution to break down the blade into epoxy fragments and fibers. The epoxy resin is then sent to Olin which can process it into “virgin-grade” epoxy, Ekstrand said.
The process uses inexpensive, non-toxic chemicals that are readily available in large quantities, she added. “We expect this to be a low energy consuming, low CO2-emitting technology.”
The company remains tight-lipped on further details, including the chemicals involved and how many times the process can be repeated.
Ekstrand said they are filing patents and the plan is eventually to license it to other companies.
So far, Vestas has tested the technology in a lab but is now building a pilot facility to test it on a bigger scale for two years, after which it hopes to commercialize it.
Vestas is far from the first to try to tackle this knotty problem. Companies and scientists have been working on different approaches for years, although many potential solutions are nascent or remain small scale.
One approach is to grind blades up and use the material in other industries. The downsides are that the enormous blades are tricky to transport and crush. “Because the material isn’t worth very much, it’s not really worthwhile doing it,” Barlow said.
But some companies say they’re making it work.
Veolia, a resource management company headquartered in France, turns old blades into an ingredient for cement production.
It shreds, sorts and blends blade materials before sending them to cement kilns. Using this blend reduces the planet-heating pollution produced in cement manufacturing by 27%, according to Veolia. The program has processed 2,600 blades so far.
Carbon Rivers, a Tennessee-based company, has worked with the US Department of Energy to help scale up its “pyrolysis” technology – a form of chemical recycling that uses very high heat in an oxygen-free environment.
The company’s process produces glass fibers, which can then be used in new wind turbine blades, as well as in the automotive and shipping industries, it says. It also produces oil that can be used in energy production, David Morgan, chief strategy officer at Carbon Rivers, told CNN.
The technology allows them “to fully and completely upcycle wind turbine blades” in a process that is “net positive energy,” Morgan added.
Carbon Rivers has so far upcycled 41 blades weighing 268 tons and is building recycling facilities and with the aim of scaling up to more than 5,800 blades a day.
Other efforts focus on changing the materials used to make turbines, to create a new generation of blades that are easier to recycle.
In 2022, researchers at the University of Michigan announced they had made a new resin for blades by combining glass fibers with a plant derived polymer and a synthetic one, which could be recycled into ingredients for products, including new turbine blades, laptop covers, power tools – and even gummy bear candies.
“We recovered food-grade potassium lactate and used it to make gummy bear candies, which I ate,” John Dorgan, a professor of chemical engineering at Michigan State University, said in a statement.
For those concerned about eating an old turbine, Dorgan said: “A carbon atom derived from a plant, like corn or grass, is no different from a carbon atom that came from a fossil fuel. It’s all part of the global carbon cycle, and we’ve shown that we can go from biomass in the field to durable plastic materials and back to foodstuffs.”
Of course, this won’t help with the blades being decommissioned now.
The reason Vestas’ discovery could be so compelling, said Barlow, is that it’s promising a process to recover reusable materials from current turbine blades, without using noxious chemicals and huge amounts of energy. “That’s a real winner,” she said.
Now the company has to scale up.
“There will be all sorts of problems which they haven’t conceived of. So it may be slow, but this is a good starter for ten,” Barlow said.
Source: https://edition.cnn.com
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