The migrating sodium ions can penetrate through the glass and accumulate at the interface of the glass and the silicon, ultimately affecting the cell's performance by creating shunts or recombination centers. Several factors influence the rate and extent of sodium ion. PID is a phenomenon that can significantly reduce the performance of solar panels, primarily driven by voltage-induced ion migration within the glass and encapsulating materials. The edge-to-center progression clearly proves electric field concentration toward the grounded aluminum frame. Physics behind the failure: Under. on soda-lime glass then immediately baked in-situ at approxi-mately 400°C for 3 minutes.