New research has proposed a cost-effective way to recycle solar panels to help handle an increasing volume of retired photovoltaic (PV) cells expected by the end of the decade.
In a paper published by a team from the University of New South Wales last week, researchers outlined a process to collect and extract valuable materials from solar arrays to see if it was technically, economically and environmentally feasible.
The process involves collecting solar arrays, stripping them of their aluminium frame, shredding the cells and using an electrostatic separation to collect valuable materials including silver and copper, reducing the panels to 2%-3% of their original weight.
The reclaimed material would then be shipped directly to a refinery for purification and processing.
Dr Pablo Dias, lead author on the study, said it showed it was possible to run a low-volume facility capable of managing 1,000 tonnes of solar panels a year. This is roughly equivalent to 50,000 panels a year, or about 4,100 panels a month.
“This is something someone can pick up elsewhere, it doesn’t use any chemicals, it doesn’t emit any pollution or hazardous pollution. It produces dust from crushing the panels, but you have dust collectors there,” Dias said.
Currently Australia has very little capacity to process and recycle solar panels when they reach the end of their life span. This is considered an increasingly pressing problem as the high uptake of rooftop solar and proposals for large-scale solar farms means a growing number of panels will reach the end of their lifespan.
A 2016 report by the International Renewable Energy Agency (Irena) found large-scale and early adopters of PV solar could expect the largest volumes of waste from old systems.
Australia was projected to generate 145,000 tonnes a year of PV solar waste by 2030, with the US expecting 1m tonnes a year and China 1.5m tonnes.
Dias said smaller-scale facilities were important as they could process material closer to their source before sending it on, reducing emissions from transport.
“You could do this in a suburb in South Australia, concentrate the valuable material and then send it directly to the refiners who do extracting and purifying the metals,” he said.
He has also since moved to put the research into practice via a start-up company, Solarcycle, which is building a facility in Texas in the US. It is expected to be operational by November.
Prof Peter Majewski, from the Future Industries Institute at the University of South Australia, who was not involved in the research, said it made “absolute sense” but cautioned against a one-size-fits-all approach.
“It’s necessary to develop a robust recycling technology and industry in that space because we’re just going to face a huge amount of solar panels coming in,” Majewski said.
“It is worthwhile to look at all different scenarios at the moment – we need to develop various ways of recycling.”
Majewski said that though there was a need to think about how to process end-of-life solar panels, it was a “solvable problem” that could be fixed with a stewardship scheme that made clear who was responsible and rules for disposing of them.
“With solar panels and wind, waste is often highlighted as this problem in a way it’s not with other discussions,” Majewski said. “Many technologies are producing waste. We can manage it. It’s a question of legislation and technology.”
