Grist recently asked the pertinent question: What happens to solar panels when they’re no longer useable?
By 2050, the International Renewable Energy Agency projects that up to 78 million metric tons of solar panels will have reached the end of their life, and that the world will be generating about 6 million metric tons of new solar e-waste annually.
So clearly we need to develop a global plan now for recycling, seeing how the life span of a panel is around 25 years. Plus, the panels have lead in them, so we don’t want that sitting in landfills. Grist explains how it’s mostly done at present:
Even when recycling happens, there’s a lot of room for improvement. A solar panel is essentially an electronic sandwich. The filling is a thin layer of crystalline silicon cells, which are insulated and protected from the elements on both sides by sheets of polymers and glass. It’s all held together in an aluminum frame. On the back of the panel, a junction box contains copper wiring that channels electricity away as it’s being generated.
At a typical e-waste facility, this high-tech sandwich will be treated crudely. Recyclers often take off the panel’s frame and its junction box to recover the aluminum and copper, then shred the rest of the module, including the glass, polymers, and silicon cells, which get coated in a silver electrode and soldered using tin and lead.
Here’s the current situation globally: In the EU, producers are required to ensure their solar panels are recycled properly. In Japan, India, and Australia, they’re coming up with a recycling plan. And in the US, with the exception of a state law in Washington that requires manufacturers to recycle the panels, there is no plan.
(At least Senator Angus King (I-ME) introduced the Battery and Critical Mineral Recycling Act of 2020 in March. The bill aims, as it simply states, “to support the reuse and recycling of batteries and critical minerals, and for other purposes.”)
There’s a cost problem in the US because it’s way more expensive to recycle than it is to dump. It costs less than $1 to dump a panel in a landfill and between $12-25 to recycle it, but only $3 is paid out for recovered aluminum, copper, and glass.
In order to recover the silver and silicon, the most valuable components, which would improve the cost-to-revenue ratio, a bespoke solution is needed.
According to [Sam] Vanderhoof, Recycle PV Solar, [one of the only U.S. companies dedicated to PV recycling], initially used a “heat process and a ball mill process” that could recapture more than 90% of the materials present in a panel, including low-purity silver and silicon. But the company recently received some new equipment from its European partners that can do “95 plus percent recapture,” he said, while separating the recaptured materials much better.
So how is this problem solved? Grist writes:
For the solar recycling industry to grow sustainably, it will ultimately need supportive policies and regulations. The EU model of having producers finance the takeback and recycling of solar panels might be a good one for the US to emulate. But before that’s going to happen, US lawmakers need to recognize that the problem exists and is only getting bigger.
Like the climate crisis, this is a future problem that must be addressed now. Renewables are absolutely the way forward when it comes to producing clean energy. But we don’t want a gigantic pile of old solar panels creating even more landfill. So the industry needs to figure out a way to reuse panels’ components and keep a whole lot of waste from piling up. Because the onus shouldn’t be on the consumer.
Thanks to Grist for exploring this vital question.
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