[londons_explore]

They're super easy to clean if you can get to them. Just 30 seconds with a regular household mop and they're shining again.

I'd recommend doing it at night, because I got a nasty zap off mine when presumably some of the mopping water got into the electrics and came up the metal mop pole .. (the electrics are all supposedly fully waterproof, but I guess on my 10+ year old panels stuff has degraded)

[darkwater]

They are on the roof, it's a two stores house, I think I will never be able or willing to do it personally :/