Sustainable Recycling Technique Recovers Silver from Expired Solar Panels

The approach ensures a 99% separation efficiency of PV cell particles


Engineers at the University of New South Wales (UNSW) in Sydney have introduced a novel method to recycle solar panels and efficiently recover valuable materials, particularly silver.

The patented process has been designed to streamline the sorting of component materials, a crucial step in achieving efficient photovoltaic panel (PV) recycling.

UNSW’s research team calculates that their process could potentially recycle 5-50 million kilograms of silver from cumulative waste by 2050. Tests have indicated the recovery of approximately 0.64 kilograms of silver per ton of PV waste.

Recycling involves integrating conventional methods with a highly abrasive separation system incorporating sieving aids.

The process includes removing large components like the aluminum frame and glass sheets, followed by crushing the panel and separating materials inside the solar cell.

Sieving helps crush solar cells into smaller particles, facilitating the separation of components, including silver.

The entire crushing and sieving process takes roughly 5-15 minutes within a vibrating container which is known to separate 99% of PV materials.

The team found that using stainless steel balls as sieving aids provided optimal results.

After separation, the team employed traditional chemical leaching and precipitation methods to extract pure silica and silver.

Recycling solar panels comprehensively has presented challenges due to their intricate integration of parts like glass, silicon, metals, wiring, and plastic, making separation difficult.

Successfully reusing solar panel components necessitates meticulous separation to prevent contamination with other materials. Manufacturers prioritize high-purity materials for reuse, a goal that has been elusive to achieve.

As a result, a significant portion of solar panels has been at risk of ending up in landfills instead of being repurposed for environmental benefits.

The research team has claimed to unveil a novel approach that ensures an impressive 99% separation efficiency of PV cell particles.

The environmental concerns associated with disposing of solar panels in landfills are significant due to the presence of harmful metals that can pollute soil and water.

According to estimates by the International Renewable Energy Agency (IRENA), global PV waste volume could reach up to eight million tons by 2030 and potentially soar to 78 million tons by 2050 as earlier generations of solar panels reach their end-of-life.

In April, Nanyang Technological University NTU Singapore partnered with Se-cure Waste Management (SWM), a Singapore-based battery recycling and processing firm, to recycle spent lithium-ion batteries using biomass.

Recently, researchers from Helmholtz Institute Ulm (HIU) and Karlsruhe Institute of Technology (KIT) devised a low-cost and eco-friendly lithium recycling technique to recover up to 70% of lithium from battery waste without the use of harsh chemicals, high temperatures, or pre-sorting of materials.