For now, however, solar energy recyclers face significant economic, technological and regulatory challenges. Part of the problem, says NREL’s Curtis, is a lack of data on panel recycling rates, which could hamper potential policy responses that could give solar-farm operators more incentives to recycle end-of-life panels instead of discarding them.
Another problem is that the toxicity characteristic leaching process — the EPA-approved method used to determine whether a product or material contains hazardous substances that may enter the environment — is known to be flawed. As a result, some solar farm owners begin to “over-manage” their panels without making a formal hazardous-waste decision, Curtis said. You will pay an additional fee to dispose of hazardous waste in approved landfills for handling or recycling.
The International Energy Agency has assessed whether solar panels containing lead, cadmium and selenium could affect human health if disposed of in hazardous waste or municipal landfills, and determined that the risk is low. Still, the agency said in its 2020 report that the findings did not prove land saturation: recycling would “further” reduce environmental risks.
NREL is currently studying an alternative process for determining whether or not the panels are hazardous. “We need to be aware of that because it affects the liability and cost of making recycling more competitive,” Curtis said.
Despite these uncertainties, four states have recently enacted laws governing PV module recycling. California, which has a lot of solar input, allows the panels to be thrown in landfills, but only after it has been verified by a designated laboratory as non-hazardous, which costs more than $1,500. As of July 2022, California had only one recycling plant accepting solar panels.
In Washington state, legislation designed to provide an environmentally friendly way to recycle PV panels will go into effect in July 2025. New Jersey officials expect to release a report this spring on regulating PV waste, and North Carolina has directed state environmental officials to study the phase-out of utility-scale solar projects. (North Carolina currently requires that solar panels be disposed of as hazardous waste if they contain heavy metals such as silver, or if they contain hexavalent chromium, lead, cadmium, and arsenic, such as old panels.)
In the EU, end-of-life photovoltaic panels are known as electronic waste WEEE under the EU Waste Electrical and Electronic Equipment Directive since 2012. The directive requires all member states to meet minimum requirements, but actual e-waste recycling varies from country to country, said Marius Modal Bakke, senior analyst for solar supplier research at Rystad Energy, a research firm headquartered in Oslo, Norway. . Despite this law, the EU’s PV recycling rate is no better than the U.S. rate — about 10 percent — largely because it’s difficult to extract valuable materials from the panels, Bakke said.
But he predicts that as the number of end-of-life panels increases, recycling will become more widespread and become a business opportunity. Governments can help speed up that transition by banning PV panels from being dumped in landfills and offering incentives such as tax breaks for anyone using solar panels, he said.
“At some point in the future, you’re going to see enough panels come loose that you can recycle them,” Bakke said. Regardless of commodity price, it will be profitable by itself.