As the world aims to rapidly build out its wind energy capacity, the difficulty in delivering fully recyclable wind turbines is leading to a looming waste problem that could threaten the industry’s green credentials.
Onshore wind turbines deployed nearly 30 years ago are beginning to pile up in landfill or be sent to incinerators because of the difficulties posed in recycling them.
Designed to withstand extreme pressures and conditions, turbine blades are difficult to recycle as a result.
While there are various initiatives to repurpose, reuse and ‘downcycle’ old wind turbine components, and some breakthroughs, a truly recyclable option has remained elusive.
With thousands of turbines needed in the coming decades, the industry’s recycling problem looks set to continue growing.
But a former sailing champion based on the Isle of Man believes he has found a solution to the elusive problem of a fully recyclable wind turbine.
A truly recyclable wind turbine?
Born in the Netherlands, Jeroen Wats became active in sailing at a young age and quickly progressed to competitive offshore and ocean racing.
In his very first transatlantic race, sailing from Cape Town to Rio de Janeiro, Mr Wats emerged victorious, though he admits his victory was “more luck than wisdom, to be honest”.
Not satisfied with his win, Mr Wats decided to develop his own racing yacht to go even further in the sport.
© Supplied by ExoTechnologiesIn 2006, Mr Wats sailed the transatlantic race again and set a record time which still stands to this day.
He would go on to build close to 650 high performance vessels, but over time he became troubled by the environmental impact of boat building.
“The moment you start to work with all these composite materials, carbon fibre and epoxies and so on, and you start to read more about what happens to these vessels at the end of their life? Well, people dump them away,” he said.
“My passion for sailing is big, but my passion for the planet is bigger.”
Recyclable composite material
In 2019, Mr Wats sold his company and embarked on a journey to develop a recyclable composite material which could be used to build power boats.
Like wind turbines, power boats are made of durable composite materials and made to withstand incredible forces.
While there are ways to break down materials like glass fibre and reuse them, Mr Wats described this as “downcycling” due to the loss of mechanical properties.
© Supplied by ContinuumWith his new company ExoTechnologies, his goal as chief innovation officer was to create a composite material which could be repeatedly recycled without any loss of performance.
“To make it circular, that’s kind of challenging,” he said.
“To make that affordable is even more challenging, and you need to make it simple as well, where every producer can switch overnight.”
DANU recyclable composite material
His answer is the DANU composite material, a patented process using natural fibres and styrene-free resins which are already widely available.
“We have a patent on the recipe, not on the ingredients,” he said.
“The trick is about separation. The fibre we have doesn’t absorb, and therefore it’s very easy to produce because you just know exactly how much resin you need.”
© BloombergThe process forms an “extremely strong bond”, and at the end-of-life the fibres and resins can be easily separated for recycling.
As a result, Mr Wats said it is possible to reuse “85% of the resins again and theoretically 100% of the fibres”.
Even if the material finds its way to landfill, Mr Wats said it will eventually “return to nature”.
“It’s not ideal (to throw them away), but you just don’t pollute the planet anymore,” he said.
DANU up to five times stronger
After developing the DANU material, he sent it for independent testing to prove it was just as durable as the materials he was trying to replace.
“You need to have something which is affordable and superior in mechanical properties because the problem with sustainability is that when it is ‘green’ people think, it’s weak or it’s inferior,” he said.
After receiving the test results from Lloyd’s Register, Mr Wats immediately phoned his business partner and ExoTechnologies co-founder Shane Mugan.
© Supplied by ContinuumMr Wats’ results showed it was up to five times stronger than glass fibre in some aspects, but with considerably fewer materials required for construction.
As a result, the overall price to build a boat using the DANU composite is about the same as with existing methods.
“But with DANU, I can recycle it and I can make something new out of it and it’s just as strong,” Mr Wats said.
In addition, the manufacturing process for the DANU composite is nearly identical to those already used in boat building and wind turbine fabrication.
Mr Wats said companies can swap their production processes “overnight”.
Fully recyclable power boat
Working with Glasgow-based boat builder Ultimate Boats, he set out to put his DANU composite to the test.
Initially, he said staff at the factory were hesitant to try his new method and more than a little sceptical. But as the first layer of fibres was laid, Mr Wats said they became immediately enthusiastic.
“The resins have no styrenes, no cobalt salt and there’s no boric acids in the fibres,” he said.
“There’s no itch, you don’t have to wear all your super protective clothing, and the end result is an exceptionally strong bond.”
ExoTechnologies and Ultimate Boats would go on to deliver a vessel for Police Scotland made from the DANU composite.
© Supplied by ExoTechnologiesAlongside being fully recyclable, the lighter weight of the material also means the boat uses 50% less fuel, Mr Wats said.
Mr Wats has also found inspiration for another use for the durable and lightweight material thanks to the Isle of Man’s famous motorcycle race.
ExoTechnologies is now working with a “leading motorcycle helmet manufacturer” on developing a prototype helmet made from DANU.
Recyclable wind turbines?
The material has also garnered interest from a security door manufacturer in Sweden, while the Dutch government is reviewing its potential for replacing steel rebar in bridge construction.
And Mr Wats believes he could achieve similar results in the wind sector.
“Our application is not the answer to everything to be fair, but for wind? Absolutely yes,” he said.
“It’s the answer for wind, no question.”
© Supplied by Forth PortsAlong with his business partner, Mr Wats has invested close to £10 million in Exo Technologies.
The company has also received seed funding from private investors, but Mr Wats said their ambition isn’t to compete with major firms like Vestas.
“The idea is a little like Gore-Tex, we have a technology, and you can get that technology for a licence,” he said.
ExoTechnologies is already in discussions with several UK wind and tidal energy companies, but Mr Wats said it is “not an easy sector to break into”.
Supersized turbines pose recycling challenge
And compared to a boat or a motorcycle helmet, the sheer scale of a wind turbine blade means the eventual recycling process would be very expensive.
“It is a challenge to make [recycling] affordable at this stage,” he said.
“The circular economy only works when your recycled materials are just as good as your virgin materials, but cheaper.”
© Supplied by Forth PortsExoTechnologies is currently working with a recycling facility in Switzerland to scale up the process, but Mr Wats said with turbine blades having a design life of 20 years there will be plenty of time to figure out the recycling part of the puzzle.
“Initially, the PET bottle was fully recyclable, but nobody knew how to recycle it. Now we have companies that can,” he said.
In the meantime, the company plans to focus on convincing wind manufacturers to consider the DANU composite for smaller components like nacelles.
Isle of Man
But ultimately, Mr Wats hopes DANU will provide a circular and sustainable renewable energy solution for the Isle of Man, a UNESCO biosphere.
The island’s government is planning to install up to five wind turbines, and Mr Wats said he is willing to provide the DANU technology free of charge.
“It would be an amazing opportunity for the Isle of Man to be leading in green technology,” he said.
“To have a fully circular wind park, nobody has it. Not the United States, not Denmark or Sweden.
“But to have one here on this windy rock in the Irish Sea would be fantastic.”
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