BEYOND THE LANDFILL: NEW LIFE FOR
GREEN ENERGY DEVICES
Efforts to find new ways to recycle and repurpose end-of-life renewable energy generation components face multiple technical and economic hurdles to achieve critical mass.
Written by Nancy Kristof • Illustrations by Gwen Keraval
“People don't understand that sometimes recycling an item is more difficult than making the original material.”
—Corby Anderson, director, Kroll Institute for Extractive Metallurgy, Colorado School of Mines
A RECYCLING RECKONING MAY be on the horizon. At some of the United States’ oldest wind and solar farms, major components—which have a current typical lifespan of about 20 to 30 years—are working past their prime, as it’s been more than 50 years since the oil and energy crisis of the 1970s first drove significant investment in such renewable energy solutions.
At the same time, recent investments in wind and solar are showing exponential growth. Annual renewable capacity additions globally increased nearly 50 percent in 2023 to hit the fastest growth rate of the past two decades, according to the International Energy Agency.
China is leading the way in solar and wind farm construction, having built more than double the capacity the rest of the world combined, according to a July 2024 report from Global Energy Monitor, with the U.S. ranking second. Meanwhile, India is setting new records in utility-scale photovoltaic installations, outpacing its 2023 investments by nearly 161 percent.
Combined with older installations quickly aging out, this explosive growth in wind energy will result in an estimated 43 million tons of used wind turbine blades by 2050, according to a study from the University of Cambridge.
So, what happens to the decommissioned components and materials from wind or solar farms once they’ve reached the end of their useful lives? The unfortunate truth is that most decommissioned parts are destined for the landfill, carrying along with them valuable materials and elements used to manufacture wind turbines and panels, such as carbon fiber, silicon, aluminum, and more.
That’s often been the cheapest option for disposal, as these components must be manufactured to not only harness nature but must also withstand it, requiring the use of epoxies, resins, and plastics—and those are difficult (and expensive) to break down.
This same concern must also be addressed with the rise of newer technologies, such as the recent use of permanent magnets comprised of either neodymium-iron-boron (NdFeB) or samarium-cobalt (SmCo), which are being used to create a magnetic field to improve reliability in some wind turbine designs. It has thus become quite the guessing game to anticipate future recycling and disposal needs.
A PATH FORWARD
While there doesn’t seem to be one agency or organization focused on uniting efforts in global renewables recycling, experts in academia, government, and private industry are taking their own steps.
In the United States, “solar panel recycling as well as full-scale rare earth magnet recycling is still in its infancy,” said Corby Anderson, director of the Kroll Institute for Extractive Metallurgy at the Colorado School of Mines in Golden. The Institute is one of the founding members of the Center for Resource Recovery and Recycling, which has a goal “to advance recovery and recycling science, engineering, and education.” The Institute has been involved with recycling PV materials and the rare earth magnets used in wind power.
“Some of it is [that] there isn't a supply out there yet,” he said. “What people don't get is you have to go gather the material [and] incentivize people.” That means approaches and progress vary.
“It’s kind of a mixed bag, globally,” Anderson continued. “Japan leads everybody because they need to recycle, because they don't have a lot of natural resources.”
In fact, the Japanese government recently announced mandates requiring solar panel recycling. The European Union is next in line, according to Anderson. Mandates such as the EU’s Waste from Electrical and Electronic Equipment (WEEE) directive place the responsibility for solar module waste disposal and recycling on manufacturers rather than consumers.
Meanwhile, the U.S. lags far behind, Anderson said.
“In order for people to do it, there has to be an incentive. People don't understand that sometimes recycling an item is more difficult than making the original material,” he explained. “The support system in the in the United States is way different than Europe, which is way different than Japan. It's as much an economic thing as it is a cultural thing.”
Part of the problem is that designers and manufacturers are dealing with unknown future uses. Another is that some manufacturers are simply looking to get the product out the door for the lowest first cost without thinking about recyclability.
“If you’re going to design for sale versus design for sale and recycle, that’s a bit of a more onerous design, because first you have to know, where is it going to be recycled, and how,” Anderson said.
DECONSTRUCTING ENGINEERED COMPOSITES
“There are a couple principal problems with recycling composites,” said Don Radford, a professor of mechanical engineering at Colorado State University in Fort Collins and the director of its Composite Materials, Manufacture, and Structures Laboratory. He has worked on a program with the Department of Energy that aims to improve recyclability in manufacturing. Those challenges fall into two groups when it comes to wind turbine recycling: technical and financial. Also factoring into the equations is high versus low value recycling.
“The goal, if we're not just grinding [the turbine] up and using as a filler for downcycling, is we're trying to extract the fiber, separate it from the matrix, and keep the fiber in a relatively viable form, which means long—not milled down into fractions of a millimeter,” Radford said.
Among the challenges to that approach is that the plastic used in a traditional turbine matrix is a thermoset. “The conventional logic is you cannot break that down except by fire or extreme solvents,” Radford said. That only adds to the environmental footprint, not to mention financial costs.
One approach could be to re-engineer the thermoset so it can be broken down chemically, reconstituted, and reused. Radford referenced successes by MIT designing thermosets that are easier to break down.
“The material result usually looks more like what they call a vitrimer than a traditional thermoset, but they can chemically reconstitute the thermoset,” he said. “Nobody does that in prime time yet.”
Another engineered solution may be to switch to using thermoplastics or more environmentally-friendly resins in wind turbine manufacturing.
“A thermoplastic, we can reheat and reform to get it to flow again. In concept, once we got them into a low viscosity form, we would be able to separate them from the continuous fiber,” Radford said.
Though there are no thermoplastic wind turbine blades in production to his knowledge, he pointed other work by the National Renewable Energy Laboratory’s to create a thermoplastic matrix wind turbine blade using a resin developed by Arkema, a private industry partner. Called Elium, the resin is a two-part liquid reactive thermoplastic that provides similar stiffness to an epoxied blade. The team’s findings also suggest that thermoplastic blades may expand the life span of the entire turbine. Other efforts NREL’s involved within include the development of PECAN, a new biomass-derivable resin. Its nickname is derived from an acronym of its chemical structure, PolyEster Covalently Adaptable Network.
“There are a couple principal problems with recycling composites. The goal, if we're not just grinding [the turbine] up and using as a filler for downcycling, is we're trying to extract the fiber, separate it from the matrix, and keep the fiber in a relatively viable form.”
—Don Radford, mechanical engineering professor and director of the Composite Materials, Manufacture, and Structures Laboratory, Colorado State University
TECHNICALLY POSSIBLE, BUT ECONOMICALLY VIABLE?
While developments to date point to a wide range of technical possibilities in renewables recycling, as Anderson and Radford point out, widespread adoption of renewables recycling requires it to pencil out financially.
“I don’t have enough information in the last six months to tell you what’s economically viable in reconstituting a thermoset, but what I can tell you is glass fibers, which make up the major tonnage of wind turbine blades, those glass fibers new cost somewhere on the order of 50 cents to $1 a pound,” Radford said.
For perspective, a 60-meter Vestas blade is comprised of about 13.5 tons of glass fiber reinforced composite.
“Currently, not too many folks believe it’s viable, from a price perspective, economic perspective, to separate them out and take a chance on the degradation that’s occurred and reuse those in high-performance applications,” Radford added.
Economics become more favorable when it comes to recovering carbon fiber due to the high costs of new carbon fiber. Retired turbine blades are also typically broken down using mechanical methods and recycled as lower-value fillers and structural materials. A 2018 study, “Economic and environmental assessment of recovery and disposal pathways for CFRP waste management,” estimated the economic value of recycled glass fiber for fiber manufacturing at Aud$390 (US$245) per ton, and that of reprocessed glass fiber composites for concrete at Aud$476.25 (US$300) per ton.
On the industry side, Veolia, a global energy company, launched a wind turbine blade recycling program through a partnership with GE Renewable Energy, which was looking for an alternative to disposing decommissioned blades in landfills.
"When we were approached five years ago by GE Renewable Energy asking us to find a way to make wind blade disposal more sustainable, we went to work analyzing the components of the blades," said Denise Kopko, senior vice president for environmental solutions and services at Veolia North America.
The solution came in the form of cutting decommissioned blades into 40-foot segments for transport to Missouri, where they’re downsized into core components at its processing facility outside of St. Louis. This blend feedstock, which includes materials such as fiberglass, resins, silica, alumina, calcium, assorted metals, foam, and wood composites, can then be used to support a cement production process that reduces carbon dioxide emissions by an estimated 27 percent.
Vestas, another major player in renewable energy, is also recycling turbines, in addition to addressing manufacturing, transportation and construction waste, said Grady Howell, program manager with Vestas American Wind Technology.
“I basically am the garbage man, if you will, for all things Vestas here in North America,” Howell said. “We take the legacy turbine blades and through various partnerships, we turn them into something new.”
The company will collect all composite materials, from blades to cell covers, hub covers, and more.
“We developed a process of mechanically downsizing the turbine blades so that the material can be used in other applications,” Howell said.
Most of Vestas’s customers want a two-cubic-inch or smaller product, and much of that is going toward applications such as cement processing or road aggregate. The material collected currently goes to a central processing facility in Iowa. Vestas expects to open another processing facility in Texas in the second quarter of 2025.
“We've gotten our recyclability up to 40 percent,” Howell added.
Other examples from private industry show interest in expanding the kinds of materials and components that can be recycled. French startup ROSI has launched with a focus on extracting the valuable silver and silicon from solar panels, and recently announced a new partnership with AGC Glass Europe to use its recycled glass in new flat glass production.
Offshore wind developer Vattenhall recently promised as part of its “commitment to circular economy practices” to expand its landfill ban to include not only wind turbine blades, but also permanent magnets, nacelle canopies, and nose cones from its wind farms, with a goal of 100 percent recycling by 2030.
The circular economy is a theme echoed by Solarcycle, a Mesa, Ariz.-based company founded in 2022 that collects and recycles used solar panels.
“Our company is a circular economy company, first and foremost, not a recycling company, which is different,” said Pablo Dias, chief technology officer and one of the company’s three founders. “If there's no marketing for that supply chain, if there's no one willing to take that material and use big, high value use, we go ahead and we create that market. We create that manufacturing facility.”
Indeed, Solarcycle is currently building two new facilities in Cedartown, Ga., to support its recycling efforts, and for which it received more than $64 million in energy credits from the Inflation Reduction Act (IRA) passed in 2022. The buildout of these manufacturing facilities follow the recent opening of the company’s headquarters and research lab in Mesa.
The solar glass manufacturing plant is expected to open in 2026 and will have the capacity to manufacture 5-6 GW of solar glass every year. A 255,000-square-foot 5 GW solar recycling plant is also under construction on an adjacent lot. The recycling plant will have the capacity to recycle and recover materials from 10 million solar panels per year, according to a company news release. Solarcycle plans to initially recycle two million solar panels per year, supplying recycled glass to its manufacturing plant and others, and will scale as market demand grows, with plans to have the capacity to process 25 to 30 percent of the United States’s retired solar panels by 2030.
“Glass today is an amazing piece of engineering material really, its specific chemistry around it,” Dias said. Though the glass can be reused in many different applications such as window or bottle glass, or asphalt, those are lower value applications.
“The best possible use for the glass is to make new solar glass. And there’s no solar glass in the country today. So that’s where the whole thing fits in,” Dias continued.
Because of the challenges in breaking apart the many layers that go into a solar panel, the firm engineered its own tools to improve the process and worked with partners to develop them, Dias said. Solarcycle’s proprietary technology allows it to extract 95 percent of the value of a solar panel’s materials and basically a reverse manufacturing line.
“We have machines that remove the glass in different ways, depending on the type of panel and the state of the panel. They have different ways to remove that glass. Then we have a process to liberate the metals, and then finally, we have a metal separation recovery process at the end,” Dias explained. “Think of this as a reverse manufacturing line that’s completely different from just chucking everything in a shredder.”
FUTURE INCENTIVES
The world’s continued thirst for energy likely means that investments in renewable energy are here to stay, though the future of U.S. government support remains unknown. Changes to the IRA’s tax credits and funding for clean energy projects or the possibility of its outright elimination have been in the headlines as the industry and pundits speculate about the direction the new administration will take with renewable energy initiatives and climate change policy. One factor in favor of continuing IRA funding may be that many projects supported by it are being developed in conservative-leaning states.
“The IRA is important, but not crucial,” Dias said. “What the IRA does is it creates all the incentives for the manufacturing of solar in the country.” He said Solarcycle’s investments to date will allow it to scale up, giving it an edge on its competition, though that’s not the reason why he and his partners started the company.
“Obviously, we need to be able to make ends meet, to get the financials in place, but the reason why we’re doing this is because we want to solve this problem,” Dias said. “There are ways to design for recycling, and that’s where we need to go eventually, as an industry, as a whole, not just the recycling industry or the solar industry—everybody.”
Nancy Kristof is a technology writer in Denver.
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