Comment by nine_k

Solar panels are usually connected to inverters or other power circuits that make the variable voltage they provide usable as a stable source downstream.

During operation a string of solar cells is under a pretty high voltage. It makes sodium ions from the covering glass infiltrate slowly into the silicon, potentially ruining the p-n junction ("potential-induced degradation", PID). Usually an industry-grade panel controller applies a reverse voltage during night time, to drive the sodium ions back from the silicon. A rogue controller might instead apply the same voltage, accelerating PID instead of reverting it (and kill it in several months). A really insidious producer might add a strip of extra sodium-rich material near the normal electric conductors, which would be triggered by voltage higher than normal operation to flood the silicon with sodium (and kill it in several days).