How a wind industry giant plans to solve its plastic waste problem

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One of the world’s largest wind turbine manufacturers says it has a potentially game-changing solution to the industry’s massive plastic waste problem. Last week, Vestas announced that it has found a new way to break down the plastic in turbine blades into new material. That way, instead of polluting landfills, it can be recycled to make new turbines.

Here’s why that’s a tall order – literally colossal. Modern turbines with blades longer than the height of the Statue of Liberty are rapidly taking over land and sea. They’re super tough, built to withstand the elements for decades. But once they are decommissioned, they usually become garbage. Globally, turbine blades are expected to be 43.4 million tons of waste by 2050.

“It can get really big.”

Vestas has so far released very little information about how its new technology recovers the plastic used to make turbine blades. But if the company manages to pull it off, it would be a game-changer for the wind industry, especially as there are major challenges to overcome.

“It can get really big. But as they say, the devil is in the details,” said Steven Nutt, professor and chair of composite materials at the University of Southern California Viterbi School of Engineering.

For starters, the turbine blades are not made of ordinary plastic. Vestas says it has found a way to recycle epoxy, which is like plastic on steroids. It is chemically designed to be nearly indestructible. Of course, that makes it strong enough to make parts for airplanes, spacecraft and wind turbines.

To understand how hard this stuff really is, we need to get a little chemistry. Most of the other plastics we encounter in our daily lives can be melted down and reformed. Epoxy is different. It is what is called a “thermoset plastic”. During the curing process, the chain molecules form nearly unbreakable bonds called crosslinks. As a result, epoxy retains its shape and chemical structure even under high temperatures and extreme conditions. You can think of it like cooked egg whites, explains Nutt: once you’ve warmed it up, cooked egg whites won’t runny again.

“Plastic on Steroids”

“[The material in turbine blades] has been optimized for decades to last as long as possible, even in really extreme weather conditions… that focus also led us to believe that it was impossible to recycle them,” Mie Elholm Birkbak, an innovation concept specialist at Vestas, tells The edge. “But now we’ve found a technical key to unlocking this potential.”

That key is a chemical process that Vestas discovered during his collaboration with Aarhus University, the Danish Institute of Technology and epoxy manufacturer Olin. The first step is to dip the blade in a liquid that separates the epoxy from other materials, 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 new quality epoxy that can be reused to make a new turbine blade.

So far, the company has only had success by demonstrating this process on a small scale using ‘pieces of turbine blades’. In a few more years, says Birkbak, “we expect to have an understanding of what this will look like on an industrial scale.” Vestas is working with Olin and recycling company Stena Recycling to scale up this pilot project.

There are still many big questions to answer. For starters, 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 time. And Vestas won’t say how many times the epoxy can be reused through the new chemical process it has devised. It is therefore unclear whether this only extends the life of the material rather than making it infinitely reusable.

There are still many big questions to answer

A typical turbine has a lifespan of about 20 years. If the blades can be reused once, it could be kept out of the landfill for a few more decades. But unless the chemical recycling process can be repeated over and over again on the same material, just kick the can down the road a little bit before sending it to a landfill.

That plastic can be reused over and over is a common misconception in recycling. Even flexible plastic is difficult to reuse. Only 9 percent of it, in the history of plastic, has ever been recycled. Usually, plastic is “downcycled” – turned into a lower value product – because of the way the quality degrades each time the material is reused. And appliances made from recycled plastic often need to be reinforced with lots of virgin plastic, a caveat that can only ultimately lead to more waste.

Vestas also doesn’t share what chemicals it plans to use in this process, other than describing them as commodities that are “readily available and relatively inexpensive,” Birkbak said. When scaling up, Vestas will have to make sure those chemicals don’t cause their own environmental problems.

The company also needs to figure out what to do with leftovers other than epoxy. Turbine blades are made with a mixture of epoxy and glass or carbon fibers. Those fibers usually make up half or more of the material. So to recycle the entire blade, the company has to reclaim everything. Plus, all of that reclaimed materials should be cost competitive with new inventory.

Still, 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. Leaf material can also be used to make cement. But those solutions, while promising, still resort to downcycling.

Vestas, on the other hand, hopes that it has found a truly circular solution to the wind energy waste problem. If successful, the new technology could even be used to breathe new life into turbines that have already been scrapped. And it could also potentially save epoxy used in aerospace and other industries.

“I’m a little excited about this. Just because, you know, Vestas has kind of stuck his neck out here,” says Nutt. After all, Vestas is a giant in the wind industry.

“It’s a great development for the industry that some of the big manufacturers are trying to become more sustainable,” said Aubryn Cooperman, a wind energy researcher at the National Renewable Energy Laboratory.

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