One of the world’s biggest wind turbine manufacturers says it has a potentially groundbreaking solution for the industry’s enormous plastic waste problem. Last week, Vestas announced that it found a novel way to break the plastic in turbine blades down into virgin-grade material. That way, instead of cluttering landfills, it can be recycled to make new turbines.
Here’s why that’s a tall order — like, literally colossal. Modern turbines with blades longer than the height of the Statue of Liberty are quickly taking over land and sea. They’re super sturdy, built to withstand the elements for decades. But once they’re decommissioned, they typically become waste. Globally by 2050, turbine blades are expected to become 43.4 million tons of trash.
“It could be really big.”
Vestas has divulged very little information so far on how its new technology recovers the plastic used to make turbine blades. But if the company can pull it off, it would be a game-changer for the wind industry, particularly since there are major challenges to overcome.
“It could be really big. But as they sometimes say, the devil is in the details,” says Steven Nutt, professor and chair in composite materials at the University of Southern California Viterbi School of Engineering.
To start, the turbine blades are not made from ordinary plastic. Vestas says it has found a way to recycle epoxy, which is like plastic on steroids. It’s been chemically engineered to be nearly indestructible. That makes it tough enough to make parts for planes, spacecraft, and wind turbines, of course.
To understand how tough this stuff really is, we have to get into a little chemistry. Most other plastic we encounter in our day-to-day lives can be melted and remolded. Epoxy is different. It’s what’s called a “thermoset plastic.” During the curing process, its chain molecules form nearly unbreakable bonds called crosslinks. As a result, epoxy will keep its shape and chemical structure even under high temperatures and extreme conditions. You can think of it like cooked egg whites, Nutt explains: once you’ve heated it up once, cooked egg whites won’t go back to being runny.
“Plastic on steroids”
“[The material in turbine blades] has for decades been optimized to last for as long as possible in even really extreme weather conditions ... that focus has also led us to believe that it was impossible to recycle them,” Mie Elholm Birkbak, a specialist in innovation concepts at Vestas, tells The Verge. “But now we have found a technical key to unlock this potential.”
That key is a chemical process Vestas discovered while working alongside Aarhus University, Danish Technological Institute, and epoxy manufacturer Olin. The first step is to submerge the blade in a liquid that separates the epoxy from other materials, which is usually glass or carbon fibers. In the second step of the process, the epoxy is treated again to break it down into its chemical components. The result, according to Vestas, is a virgin-grade epoxy that can be used again to make a new turbine blade.
So far, the company has only had success demonstrating this process on a small scale using “pieces of turbine blades.” After a couple more years, Birkbak says, “we expect to have an understanding of how this will look on an industrial scale.” Vestas is working with Olin and recycling company Stena Recycling to scale up this pilot project.
There are a lot of big questions left to answer. To start, Vestas says its process can recover a “majority” of the epoxy in old blades, but the company doesn’t have a concrete number to share at this point. And Vestas won’t say how many times the epoxy can be reused through the new chemical process it devised. So it’s unclear whether this merely prolongs the life of the material rather than rendering it infinitely reusable.
There are a lot of big questions left to answer
A typical turbine has a lifetime of about 20 years. If its blades can be reused one time, that might keep it out of the landfill for a couple more decades. But unless the chemical recycling process can be repeated on the same material time and again, you’re only kicking the can a little bit down the road before sending it to a landfill.
That plastic can be rehashed again and again is a common misconception with recycling. Even pliable plastic is difficult to reuse. Only 9 percent of it, in the history of plastic, has ever been recycled. Most of the time, plastic is “down-cycled” — turned into a lower-value product — because of how the quality degrades each time the material is rehashed. And devices made using recycled plastic often have to be reinforced with a lot of new plastic, a caveat that can ultimately just lead to more waste.
Vestas also isn’t sharing what chemicals it plans to use in this process other than describing them as commodities that are “readily available and relatively cheap,” according to Birkbak. Scaling up, Vestas will need to ensure that those chemicals aren’t causing their own environmental problems.
The company also has to figure out what to do with other leftovers aside from epoxy. Turbine blades are made with a blend of epoxy and glass or carbon fibers. Those fibers typically make up half or more of the material. So to recycle the whole blade, the company has to reclaim it all. Moreover, all those reclaimed materials would have to be cost-competitive with virgin stock.
Nevertheless, the growing wind industry will have to figure out what to do with all those old turbines. In Europe, turbine blades have been used to build bridges. Blade material can also be used to make cement. But those solutions, while promising, still resort to down-cycling.
Vestas, on the other hand, hopes it has found a truly circular solution to wind energy’s waste challenge. If it’s successful, the new technology could even be used to breathe new life into turbines that have already been discarded. And it could potentially rescue epoxy used in aerospace and other industries, too.
“I’m kind of excited by this. Just because, you know, Vestas has sort of stuck their neck out here,” Nutt says. Vestas is, after all, a giant in the wind industry.
“That’s a great development for the industry that some of the major manufacturers are trying to be more sustainable,” says Aubryn Cooperman, a wind energy researcher at the National Renewable Energy Laboratory.