By the end of 2024, the world will be almost 2000 Gigawatts solar power generation capacity in service. Each panel is made from an assortment of silicon, glass, various polymers, aluminum, copper, and other metals that capture solar energy. This is a rule that, barring damage, the panel will last up to 30 years before it needs to be replaced. But what happens to all these raw materials when the current crop of solar panels becomes obsolete? We certainly aren’t a waste all of them, we?
What kills a solar panel?
Received wisdom suggests that solar panels last about 30 years, but that’s not the whole story here. “30 years are ours best guessGarvin Heath of the National Renewable Energy Laboratory (NREL) explained. NREL found that there is a higher failure rate early in a panel’s life, often due to manufacturing or installation errors. Only a few panels fail in middle age. Then the statistics begin to climb northward as you approach the three-decade mark, but even so, the number of broken panels is “less than one percent” of the total number in operation at that time.
Matt Burnell is the founder ReSolar, A British start-up is looking into the reuse, energy supply and recycling of solar panels. As part of his work, Burnell visited a 40,000-panel solar farm where 200 panels broke during installation. “I took about 50 from that site, tested them to see their value for reuse [and] manufacturing capacity,” he said, most of which were within the “manufacturer’s tolerance range.” Except for the odd crack in the glass or a bump in the frame — which could cause problems down the line — the panels otherwise worked perfectly.
If a panel survives birth and installation, the biggest killer of solar panels is weather. Heath said a common cause is extreme weather events that damage the panel, or even normal, aggressive weather conditions that cause performance degradation. Unfortunately, once the panel is broken, it is not worth spending a lot of time to repair it.
Thus, panels considered “broken” during manufacture or installation may still be capable of harvesting energy from the sun. But there are also many panels that are retired after 25 or 30 years, even if they don’t break in any meaningful way. There’s a fairly simple reason why solar farms don’t allow these panels to absorb the rays until they stop working.
It’s the economy, stupid.
The main issue is the loss of efficiency, meaning the panels can’t produce as much power as they did when they were first installed. Most solar panels are made of laminated adhesive layers that sit between the glass and solar cells to hold them together and help with durability. Sun exposure can cause these laminated layers to discolor and reduce the amount of light that can reach the cells. This reduces power generation capacity, which is a problem for large commercial farms.
“The manufacturer’s warranty is theirs [solar] performance of the modules over a 30-year period,” explained Garvin Heath. For example, a manufacturer will promise that its panels will be at least 80 percent efficient for the bulk of their expected three-decade lifespan. These warranties give large utility-scale customers confidence in what they’re buying, and when they expire, it’s often more cost-effective to just trash them and replace them.
Power grids have a limited number of interconnects, mainly on-ramps that allow them to deliver power to the grid. Each link has a hard upper limit on the power it can send, so solar farms must always produce the maximum allowed amount of electricity. “[Even when] They work within warranty, the opportunity cost of producing a module [more] The power in your interactions is incredibly valuable,” Heath said.
Matt Burnell of ReSolar used the example of a 10 Megawatt solar farm in the UK with a 15 Megawatt interconnection. “Ten years ago, they could only fit 10 megawatts in the space they had […] but it is now financially viable for them to dismantle and rebuild the asset with newer and more efficient modules.” “You’ve got these big pension funds, you’re looking at it on a spreadsheet,” and you’re looking for ways to better leverage their investments. The result is that all these thin panels are damaged. “When you think about the internal carbon of the haul [the panels] it’s over [from China]” said Burnell, “and they go into the waste stream […] looks crazy.”
Even if the panels can be repaired with full efficiency, it is unlikely that solar panel repair shops will open en masse. “There’s a serious question about the labor costs of testing and repairing compared to just buying a new panel,” Burnell said. He added in another example of panels that had to be removed to meet fire safety legislation, there was a similar risk of being thrown away because the effort to replace them was too great. To reduce waste, ReSolar has actually stopped collecting and shipping sending those panels to Ukraine for hospital use.
In the trash
Another basic rule that is, only one out of every 10 solar panels is recycled, and the remaining nine are sent to landfills. There is no standard way to track the panel’s final destination, and it is unclear how such a system would be implemented. But there is a risk that the landfills will be filled with the volume of panels that will come down from the roofs. Los Angeles Timesfor example, has reported the convergence of panels in California since 2006, after the state pushed for more solar installations.
The legal situation is hardly patchwork, Grist Describing what’s happening in 2020 as the “wild west” because only Washington has any binding laws. Decommissioned solar panels depending on the materials used in its construction, it is covered by federal solid and hazardous waste regulations. If the panel contains heavy metals such as lead and cadmium, they should not be sent to a general landfill to prevent their poisons from leaching into the soil. But this often means diverting those panels to landfills designed to handle special waste.
EPA is currently reviewing development of rules will standardize the recycling process for solar panels and lithium batteries. But with no federal mandate or even strict state-level laws for recycling, the situation is far from ideal. A small fraction of the panels are actually sent to recycling centers, while the rest are left to an uncertain fate. As Heath points out, the risk is that while recycling is uneconomical and unaffordable, we’ll see giant gardens of solar panels that stack up and work when things change.
In the UK and Europe, solar panels are covered by the Waste Electrical and Electronic Equipment Directive or WEEE. The rules oblige the supplying companies to collect and recycle the discarded panels, or to have another entity pay for it. This means that, hopefully, we won’t see tons more panels being thrown into landfills, and it also means that it will often be more cost-effective to recycle working panels instead of reusing them.
Recycling
If you want to unload the raw material hidden inside the solar panel, then there are two approaches. There’s a mechanical way you can break apart components, which is both simpler and more wasteful: it can recover glass and metal, but little else. Or there are thermal and chemical approaches that attempt to separate the components, allowing more of the rarer metals to be recovered.
“Existing recyclers have traditional markets that their economics are built around, so glass recyclers look at a module and say, ‘Wow, 80 percent of the weight of a module is glass, I know what to do with that,'” Heath said. there are more precious metals of value,” he said, “but they are mixed with plastic polymer layers. […] it is difficult to separate economically. Consequently, the silicon, silver, and copper incorporated into the cells are often ground up en masse and discarded.
The IEA 2024 report looked at how these mechanical methods of panel recycling are not good for material qualities. “The results of machining are usually not very clean and produce better products than high quality materials […] Silicon and silver should be targeted in particular.” He added that often these recycling processes are not optimized to run solar panels, and so “there is often a slight reduction in the quality of the recovered material,” which is hardly a great step on the road to circularity.
It’s also hard to know what goes into a solar panel. “Variety of materials [found in solar panels] does wild”, said Matt Burnell of ReSolar. A litany of manufacturers don’t yet have to share their raw material data, though the new rules will change soon. Until then, it’s hard for recyclers to know what to get out of the panels they want to recycle.
In addition to the fact that recyclers do not know the composition of the panels, there is a risk that harmful chemicals are added to speed up some processes. Antoine Chalaux is the general manager ROSI SunSolar panel recycling specialist in France. He spoke of the presence of chemicals such as Teflon and antimony, both of which are toxic and cannot be released into the atmosphere. “We have developed our recycling processes to capture [them]”, he explained, “but we push on [manufacturers] to use less [in future].”
Burnell believes the industry is really in the “very dawn” of solar recycling, but is confident that with investment today, solutions will be found in the very near future. “We have this huge lead time,” he said, “so we know what’s coming into the market today and we know what’s coming into the system 25 to 30 years from now.” The real ticking clock is for the large number of panels installed in the early 2010s that will begin entering the waste stream over the next decade.
Currently, ROSI’s processes are not as cheap as other recyclers, and Chalaux knows this can be a problem. “There is no economic reason for companies at the moment [recycle with us]but there is an image issue,” he said. “Manufacturers and owners of all PV projects want a good end-of-life story for their panels.” Another benefit of this process is the production of high-purity recycled materials that can be used by local manufacturers.
The future
One step toward a more recyclable solar panel could be to eliminate the use of those adhesive polymers in its construction. If a panel could simply use sheets of glass with solar cells glued inside, it would be very easy to disassemble. Not to mention you’ll get longer and better performance from them, because there would be no discolored polymer layers.
Thankfully, a team from the United States National Renewable Energy Laboratory (NREL) demonstrated that such a product could exist. Instead of gluing the layers together, femtosecond lasers weld the front and back panels of the glass together. The solar cells are trapped inside, held in place by bonding the glass to its brother, nothing else. And finally, when the panel reaches the end of its life, which can be more than 30 years, it can be recycled by breaking the glass.
The project, led by Dr. David Young, says that if proposals are accepted, we could see a commercial version of the panel within two to three years. He added that the rigidity offered by welding would be as strong and waterproof as panels using polymer layers. Unfortunately, by this point we’ll have decades of panels using the old system and still have to deal with it. And until we have a cost-effective, scalable way to recycle them, ‘What happens to solar panels when they die?’ ‘nothing good will happen.’
