It’s hard work soaking up sunlight to generate clean electricity. After about 25 to 30 years, solar panels wear out. Over the years, heating and cooling cycles stress the materials. Small cracks develop, precipitation corrodes the frame and layers of materials can start to peel apart.
In 2023, about 90% of old or faulty solar panels in the U.S. ended up in landfills. Millions of panels have been installed worldwide over the past few decades – and by about 2030, so many will be ready to retire that they could cover about 3,000 football fields.
As an electrical engineer who has studied many aspects of renewable energy, recycling solar panels seems like a smart idea, but it’s complicated. Built to withstand years of wind and weather, solar panels are designed for strength and are not easy to break down.
The cost conundrum
Sending a solar panel to a landfill costs between US$1 and $5 in the U.S. But recycling it can cost three to four times as much, around $18. And the valuable materials inside solar panels, such as silver and copper, are in small amounts, so they’re worth about $10 to $12 – which makes recycling a money-losing prospect. Improvements in the recycling process may change the economics.
But for now, it’s even hard to reclaim the glass in solar panels. Many layers are glued together and need to be separated before they can be melted down for reuse. And if the separation is not precise enough, the glass that is recovered won’t be of high enough quality to use in making other solar panels or windows. It will be suitable only for lower-quality uses such as fill material in construction projects.
Other panels, usually older ones, may contain small amounts of toxic metals such as lead or cadmium. It can be difficult to tell whether toxic materials are present, though. Even experts have trouble, in part because current tests, such as the toxicity characteristic leaching procedure, can give inaccurate results. Therefore, many companies that own large numbers of solar panels just assume their panels are hazardous waste, which increases costs for both disposal and recycling. Clearer labels would help people know what a solar panel contains and how to handle it.
If someone wants to recycle a solar panel, and is willing to bear the cost, there aren’t many places in the U.S. that are willing to do it and are equipped to be safe about it.
Designing for a new life
Despite the Trump administration’s cuts to subsidies for solar projects, millions of solar panels are already in use in the U.S., and millions more are expected to be installed worldwide in the coming years. As a result, the solar industry is working on ways to minimize waste and repeatedly reuse materials.
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