In recent years, wind energy has become a bigger and bigger part of Texas’ power portfolio. And as it’s become more common, so have questions about what happens to those big turbine blades that catch the wind and spin to produce power.
The blades are good for about 20 years, but after that, most of them get piled up in turbine graveyards with no clear re-use. They’re not biodegradable.
A team at the National Renewable Energy Laboratory in Colorado may have a solution, however: a turbine blade that can be recycled. Nicholas Rorrer, senior researcher at the laboratory, spoke to the Texas Standard about how it works.
This transcript has been edited lightly for clarity:
Texas Standard: You and your team developed a wind turbine blade that, under the right circumstances, will break down. Explain what it’s made of and how that works.
Nicholas Rorrer: So in a lot of our work, our approach was to look at kind of how wind turbines are made today and enable kind of a material that could undergo all the same manufacturing conditions but come from possibly bio derived resources and really be recyclable at the end of life through kind of known chemical linkages.
And so in our work, that’s effectively what we did, is we started with the application. We said, Hey, we want to make wind turbine blades. How are those made? They’re made through this process called vacuum assisted resin transfer molding, where you effectively pull kind of a thick viscous resin like honey through a bunch of fibers, and then you heat it up and you cure it and it makes a hard part.
And so what we did is we looked through our kind of entire chemistry textbook and our resources that we knew of what we could get bio derived. And we found specific materials that we could get from bio derived resources that were non food competitive that could undergo all the same manufacturing conditions, yet have these recycling linkages that we knew how to break down at the end of life.
How much more expensive might this be to make than a conventional turbine blade?
I mean, it’s a really hard question to answer. But when we look at our resins themselves, they’re near cost competitive to what’s made kind of today from epoxy amine materials. So today’s wind blades are made out of these epoxy amine resins. And for our stuff, we use kind of a bio derivable epoxy and hydride resin. And the costs are, you know, maybe plus or minus 10%.
But, you know, when you look at a wind turbine blade, you also have to consider that right now today’s manufacturers of wind turbine blades consider end-of-life disposal also in their cost. So if we actually have something that enables us to get around end-of-life disposal, you might end up saving costs.
So I would really say like maybe the initial blade could be up to 10% more expensive. But when you actually consider all the factors across the life of these materials, it might be very cost competitive, if not cheaper.
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Are there any questions about the long-term durability of these blades?
That’s one of my favorite kind of questions about the work that we did that was recently published in Science. Right now, kind of in the academic literature or even kind of a cultural perception, we sometimes think that something made out of recycled material or something that can be recyclable is like less efficient than something that’s durable.
But really, we did the analysis and we kind of made a nine meter wind turbine blade and we showed that actually our materials themselves creep less. So they kind of deform less over time than today’s standard materials. So for all intents and purposes, these materials from like a mechanical performance should last just as long, if not longer.
And when we did advanced weathering studies – so kind of exposing these things to harsh UV light or other conditions – we saw no detriment in performance compared to today’s incumbent materials. So everything really points to the fact that these should perform at least as long as today’s materials, if not better.
Very interesting. How would manufacturers have to change their current processes to accommodate this new technology?
I think that the big thing is when we set forth in our approaches, we made sure that today’s wind manufacturers could actually still use their current technology for doing so. We made sure we developed something that actually met all the requirements.
To some extent, that’s kind of a unique approach to our science that people don’t always do. But we were making sure from day one that we were meeting those manufacturing requirements in doing so. And so honestly, nothing. I think the hardest part they would have to do is find suppliers for these materials.
What’s the next step in your research?
I think composite structures themselves, we often think about them in wind, but they’re materials that can also be used in vehicles and beyond that. So I think our work itself is going to understand like where else can we apply these fundamentals to enable kind of circularity in more applications beyond wind – or even when we think of wind energy, we often sometimes also think of water power because water power has a lot of similar requirements but different.
So we’ll probably look at things saying, Hey, can we make a water power turbine – that, you know, we might not see when driving across the country, but certainly exist – recyclable by design itself. So I think it’s broadened into our application scope. And then science itself is always an iterative process. So really making sure that these materials are performing best as we go into longer and bigger scales.
