Researchers recover almost 100% of the silver from solar panels

In used solar panels, a University of Newcastle team has just recovered almost every last gram of a discreet but valuable metal. Almost 100% of the silver present was recovered in a test conducted on 468 kg of end-of-life solar panels. Processing the material from the cells took 90 minutes.

The process avoids acid-based techniques. The panels are first dismantled and then crushed to isolate the material from the photovoltaic cells. This material is immersed in water, after which air and specific reagents are injected: the silver clings to the bubbles and rises to the surface in a foam that the researchers can then collect.

The test produced 22 kg of solar cells. In this material, silver accounted for 1.25% of the total mass of the materials processed. The final product was 80 times more concentrated in silver than the photovoltaic cells. For the team, these results show that flotation separation is reliable, fast and scalable.

So what does this mean in practice? Recovering silver could improve the economics of photovoltaic recycling. In Australia, the researchers say that recycling panels still costs more than sending them to landfill. The value of the metal could therefore help fund an industry that avoids both landfill and the extraction of new resources.

The issue goes beyond recycling alone. Silver acts as a conductor in solar panels, and the global photovoltaic industry accounted for 30% of annual silver consumption in 2024. Recovering the silver already present in end-of-life equipment could strengthen the resource sovereignty of countries such as France. These figures nevertheless come from a test conducted by the research team: no independent validation under industrial conditions is mentioned.