Millions of solar panels have been installed in the last two decades, and since they typically last 25-30 years, many will soon be ready for recycling of solar panels and likely headed for the landfill. But new efforts to recycle these panels could reduce both the amount of waste and the new material that needs to be extracted.
Only about 10% of panels in the US are recycled; federal regulations don’t require it, and recycling devices are currently much more expensive than simply disposing of them. But the solar panel materials that go offline each year could be worth an estimated $2 billion by 2050. New efforts, including an approach by a French startup called ROSI, are trying to recover these valuable materials, especially silver. And silicon, to make recycling the best.
Expanding solar energy production is key to reducing emissions around the world, but the recycling of solar panels is an inevitable part of the process which needs to be done right. Globally, solar panels produced 720 terawatt-hours of power in 2019, accounting for about 3% of global electricity generation. And that took around 46 million metric tons of solar modules to get that done.
Are old solar panels recyclable?
About 8 million metric tons of obsolete solar panels can accumulate throughout the world by 2030. By 2050, that number can get to 80 million. No one knows what percentage of solar panels are recyclable at that point.
The recycling process of solar panels could provide a new source of materials that would otherwise have to be extracted (potentially in unsafe working or exploitative conditions), making solar energy a more sustainable piece of the clean energy puzzle.
What’s in a solar panel?
Solar panels like the JA solar panels are arranged as a sandwich with cells in the center. To know more about these panels check out the JA solar panels data sheet. Around 90% of commercial solar panels use silicon as a semiconductor, which converts light into electricity. Thin strips of metal, usually silver, crisscross the surface of the silicon crystals in each cell and move electricity to the panel’s copper wiring. Every solar panel has its lifespan and when the inner components like the solar DC cable are worn out, it’s time for the recycling of solar panels.
Solar cells are encased in a protective barrier, usually a clear plastic called EVA. Another layer of glass goes on top and another type of plastic, like PET, covers the back. Everything is surrounded by an aluminum frame, and the whole panel is mounted on the solar structure to buy, which is an example of the challenges of recycling solar panels.
This layered construction protects the cells from the elements while allowing sunlight to pass through, but can be difficult to disassemble when the panels have reached the end of their useful life.
How is the recycling of solar panels done?
Some companies try to restore and reuse panels that have lost efficiency or at least salvage some of their components, like the hybrid inverters solar systems use. Reuse is the easiest and cheapest way to “recycle” panels: it requires the least processing and has the highest price.
A panel can cost around $55, while a used panel can be resold for around $22. Or the used panel components could sell for as much as $18 total, according to Meng Tao, an engineering professor at Arizona State University and founder of a solar panel recycling startup called TG Companies.
Used panels that cannot be resold go to the landfill or some form of recycling of solar panels. As there were no federal mandates, Washington recently passed recycling requirements for manufacturers, and the rest of the states are now thinking about doing the same. Meanwhile, the EU requires manufacturers to collect and recycle used solar panels and fund research into end-of-life solutions for the technology they produce.
In 2018, waste management company Veolia, based near Paris, opened what it says is the first recycling line dedicated specifically to the recycling of solar panels. Located in Rousset, France, the plant also uses a mechanical recycling process, although since it is designed for solar panels, more components are recycled separately than at facilities that use general e-waste recycling equipment. But some corporations are planning on using other methods, such as chemical and thermal processes because they’re even more efficient.
Giving old solar panels a second life
ROSI Solar, a French startup founded in 2017, recently announced plans to build a new plant in Grenoble, France for the recycling of solar panels. Yun Luo, CEO of ROSI, says the company has developed a process to extract silver, silicon, and other high-value materials from used panels. The recycling plant should start operating before the end of 2022 as they have a contract from Soren, a French trade association.
Soren is also working with a French logistics company called Envie 2E Aquitaine, which will try to find other uses for the decommissioned solar panels. If the panels are not operational, the company will remove the aluminum frame and glass before turning them over to ROSI for recycling, says Luo.
ROSI focuses on recovering high-purity silver and silicon, as these two materials account for more than 60% of the cost of a panel. The corporation uses a chemical method on the rest of the layers, focusing on removing the small silver threads that transmit energy through a functioning solar panel, like the Canadian Solar Panels.
Luo declined to go into details on how to recycle used solar panels but says the company can recover almost all of the silver in solid form, which makes it easier to separate from the rest of the metals, such as tin and lead. Luo says the company also recovers the silicon in a form pure enough to process and reuse in new EV panels or batteries.
To be profitable, ROSI will need to recycle at least 2,000 to 3,000 tons of panels per year, says Luo. Soren expects to collect about 7,000 tons of panels in 2021, and that number will likely double by 2025.
However, prices for recycled materials can be quite volatile. When Tao published a review article on the recycling of solar panels in June 2020, he estimated that the value of raw materials that could be extracted from a used panel would be around $10 considering the cost of recycling solar panels. Recycling solar panels can be quite profitable, if done right and if you consider the solar panel price.