Energy
New method recovers high purity silver from solar waste
French researchers have developed a recycling technique that extracts silver from spent photovoltaic modules without using nitric acid.
Key points
- The leaching process strips base metals while leaving silver behind in under 10 minutes.
- Laboratory tests show a recovery rate exceeding 98% with low silver losses.
- The technique avoids harmful nitrogen oxide emissions generated by standard acid methods.
What happened
Scientists at the Alternative Energies and Atomic Energy Commission in France have created a novel hydrometallurgical technique to process end-of-life solar panels, pv magazine reported. The approach uses hydrochloric acid and hydrogen peroxide to dissolve aluminum, copper, lead and zinc from the waste materials.
Unlike traditional procedures that rely on nitric acid, this method leaves the precious metal intact. It forms an insoluble silver chloride shell that protects the core from degradation during the leaching phase. A density-based separation step then isolates the material from silicon.
Why it matters
Although silver accounts for a minimal fraction of a solar module by weight, it represents the majority of its economic value, according to the researchers. Efficient recovery methods are becoming crucial as the renewable energy sector scales up operations and anticipates larger volumes of decommissioned infrastructure.
Standard hydrometallurgical treatments often create nitrate-rich effluents and nitrogen oxides. By avoiding nitric acid and allowing the reuse of leachate across multiple cycles, the French team's approach offers a potentially cleaner alternative for industrial recyclers.
What comes next
The laboratory-scale process has been tested in a 20-litre pilot reactor, funded by the European Union Horizon Europe EVERPV initiative. Further downstream procedures, such as electrowinning or chemical reduction, remain necessary to transform the recovered composite into commercial metallic silver.
Original reporting
This article draws on the following reports. Read them in full on the publishers’ sites.
Context from CEII
CEII follows developments across the world’s energy system and connects them to the data behind them.
Countries in this story
Written by the CEII Desk, the Centre’s automated newsroom, from the reporting credited above and CEII’s own data. Facts are attributed to their sources; the publishers have not reviewed this article. Spotted an error? Tell our editors.
