Solar panels are a pain to recycle. These companies are trying to fix that.


Expanding solar energy production is key to reducing emissions around the world. Globally, solar panels have been produced 720 TWh of energy in 2019, accounting for about 3% of the world’s electricity generation. It took 46 million metric tons of solar panels to do so.

About 8 million metric tons of decommissioned solar panels could accumulate globally by 2030. By 2050, that number could reach 80 million. Recycling these slabs can provide a new source of materials that may need to be mined (potentially unsafe or exploitative working conditions), making solar a more sustainable piece of the clean energy puzzle.

What is in solar panels?

The solar panels are placed like a sandwich with the cells in the middle. About 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 silicon crystals in each cell and conduct electricity to the plate’s copper wires.

The solar cells are encased in a protective barrier, usually a clear plastic called EVA. There is another layer of glass on top, and the back is covered with a different type of plastic, such as PET. Everything is enclosed in an aluminum frame.

This layered construction protects the cells from the elements while allowing sunlight to pass through, but it can be difficult to break them down when the panels reach the end of their life.

second life

Some companies are trying to refurbish and reuse boards that have lost their efficiency, or at least salvage some of their components. Reusing is the simplest and cheapest way to “recycle” panels – it requires the least processing and the highest price.

A board may cost around $55, while a used board may resell for around $22. Or used board components may sell for a total of $18, according to Meng Tao, who is a professor of engineering at Arizona State University and founder of a solar panel recycling startup called TG Enterprises.

Although some sellers offer used boards for sale to resident customers, they do not offer much price savings. Panels, at most, make up about half the cost of a residential solar array, with other equipment and permits making up the rest. Since used panels do not generate much electricity, the money saved by purchasing them may not be worth it.

Used plates that cannot be resold are intended for landfill or some form of recycling. In the absence of federal states, Washington It recently passed the recycling requirements for manufacturers, and other countries are now considering doing the same. Meanwhile, the European Union requires manufacturers to collect and recycle used solar panels and funds research on end-of-life solutions for the technology they produce.

About 8 million metric tons of decommissioned solar panels could accumulate by 2030.

Some waste facilities can recycle solar panels using mechanical methods. Most of them blow out of the aluminum frame and grind all the glass, silicon, and other metals into a mixture called vitreous, which can be sold for building materials or other industrial applications.

But a glass caper doesn’t cost much – about $3 for a plate of batter. It is not clear whether there will be buyers for all the glass crusher that will result from recycling more solar panels, Tao says. The ability to extract pure and valuable materials may help make recycling more profitable.

In 2018, waste management company Veolia, based near Paris, opened what it says is the first recycling line developed specifically for recycling solar panels. The plant is located in Rousset, France, and also uses a mechanical recycling process, although because it is designed for solar panels, more components are recycled separately than facilities that use general e-waste recycling equipment. But some companies are betting that other methods, such as thermal and chemical processes, will be more efficient.

old plate mining

ROSI Solar, a French startup founded in 2017, has announced plans to build a new recycling plant in Grenoble, France. Yun Luo, ROSI’s CEO, says the company has developed a process to extract silver, silicon and other high-value materials from used panels. The plant is supposed to open before the end of 2022 under a contract from the French trade union Surin.

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 aren’t ready to go, the company will remove the aluminum frame and glass before passing it on to ROSI for recycling, Low says.

ROSI focuses on recovering solar-grade silver and silicon, because these two materials make up more than 60% of the panel’s cost. The company uses a proprietary chemical process on the remaining layers, with a focus on removing the tiny silver strands that transmit electricity through a working solar panel.

Luo declined to go into details but said the company can recover nearly all of the silver in solid form, so it’s easy to separate from other metals, such as lead and tin. Lu says the company is also recovering the silicon in a form pure enough to be reused in new panels or EV batteries.

To be profitable, ROSI will need to recycle at least 2,000 to 3,000 tons of panels annually, says Low. Soren expects to collect about 7,000 tons of panels in 2021, and that number is likely to more than double by 2025.



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