I’ve since had them partially cleaned and they seem fine. Not sure what it was? Some sort of algae maybe. I asked about shorts and was told the inverter checks before starting up. What cleaners can I use? Any links.

heres a pic.

Also what happened to the Navitron forum it seemed to have more people? is there a good Facebook group that deal with solar PV?

This is ridiculous, had one company try and clean them from the ground, wouldn’t come off. Another company said if they have to clean from the ridge they need to charge more. im tempted to go up there and clean them myself. on a side note one cleaner said if he could use biocide on the panels it would come off easy. Anyone know if it would damage the panels?