The older they get…
Drone thermography image from 20 meters of flight altitude (left) and drone electroluminescence image at five amperes of current (right). PID was discovered in a 58 kilowatt rooftop system from 2014. The modules have been regenerating with offset boxes since November 2017. This string has improved very little however. In the IR image, it cannot be seen where the string begins. But in the EL scan the individual string is clearly visible and it is possible to see the weakness caused by the PID effect from the negative to the positive pole. The first two modules at the negative pole are marked.
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