In 2016, the International Renewable Energy Agency estimated that as much as 78 million tons of solar-panel waste will be generated by 2050. That’s almost certainly an undercount. Over the past decade, falling prices and improved efficiency in newer models have offered a strong incentive to replace solar panels earlier than their intended lifespan. By one estimate, those upgrades could lead to 50 times more waste than the agency has predicted within five years.
In developed countries, recycling — not reuse and resale — tends to be the kneejerk response to managing such waste. But there are two problems with recycling unwanted solar panels. First, doing so is far costlier than simply landfilling them. Second, waste panels often aren’t waste; they’re just degraded by time in the sun or less efficient than newer models. They may not be good enough for San Francisco homeowners and cutting-edge utilities, but they work perfectly well for anyone in a sunny climate in need of stable, off-grid power who doesn’t want to pay full price.
That’s potentially a huge market. Between 2010 and 2019, the number of people living without electricity declined from 1.2 billion to 759 million worldwide. Some of that gap was closed by new power lines and other transmission facilities. But most of it was achieved by installing small solar systems designed to power a village, farm or even a single home. As of last year, 420 million people got their electricity from off-grid solar systems. By 2030, according to the World Bank, that number could nearly double.
Nobody knows how much of this market has been met by secondhand panels and systems. But the volumes already being sold are tantalizingly large. Laid Sahraoui, founder and managing director of Hong Kong-based R3 Tech, a major broker, “pessimistically” guessed that there are 10 million used solar panels on the global market. Melissa Schmid, of EnergyBin, a Minnesota-based exchange for buyers and sellers of used and overstocked solar equipment, told me that the company markets 1.5 million pieces of photovoltaic equipment on its site. “At points, we have five million.”