Researchers found that running a 10 milliamp direct current through a microbial leaching system makes bacteria extract silver from old solar cells much faster. In bench scale reactors, the current boosted cyanide production by 58 percent and raised dissolved silver to 6.43 mg/L, about 8.8 times the level in an unassisted control. The electric field also changed the microbial community, favoring bacteria that convert amino acids into cyanide more efficiently. That matters because solar panel waste is expected to reach 95 million metric tons by 2050. Most panels are crystalline silicon and contain silver that is hard to recover without smelting or strong chemicals. Faster biological leaching could give recyclers a lower energy, lower waste option for recovering value from decommissioned panels. Still, this is lab scale work with silver powder, not real crushed panels. The next step is testing on actual PV waste and measuring total energy and cost per gram of silver recovered.
