SEATTLE (Waste Advantage): Solar power is booming. Global photovoltaic capacity grew from 1.4 GW in 2000 to 760 GW in 2020, and solar power now generates almost 4% of the world’s electricity, according to the International Energy Agency. But experts say this astonishing growth in low-carbon power is also a ticking time bomb. More than 90% of photovoltaic (PV) panels rely on crystalline silicon and have a life span of about 30 years. Forecasts suggest that 8 million metric tons of these panels will have reached the end of their working lives by 2030, a tally that is projected to reach 80 million t by 2050. But today’s technologies for recycling these units are inefficient and rarely deployed.
That is an enormous problem. PV panels contain toxic materials, like lead, that can cause environmental pollution, yet many are dumped in landfills when they die. They also contain valuable materials that could be reused to make new solar cells, but today these resources are mostly wasted. In the US, there are no federal regulations to mandate PV recycling, and according to the US National Renewable Energy Laboratory (NREL), less than 10% of the country’s decommissioned panels are recycled. Even in the European Union, where legislation requires PV recycling, many waste facilities merely harvest bulk materials like aluminum frames and glass covers, which make up over 80% of a silicon panel’s mass. The remaining mass is often incinerated, even though it contains elements like silver, copper, and silicon, which together account for two-thirds of the monetary value of a silicon panel’s materials.
Companies and researchers are now racing to prepare for the looming tsunami of PV waste. They are developing technologies that promise to recover far more of the useful materials from cells while reducing the costs and environmental impacts of recycling. NREL says that it costs about $15–$45 to recycle a silicon PV module in the US but only $1–$5 to dump it in a landfill. So cheaper processes that extract more economic value from PV waste─alongside more restrictions on landfilling─could help tip the balance in favor of recycling.