The wet surface seems better at absorbing sunlight than the 'anti reflective' glass surface, and the evaporating water is a great cooler.
Since it uses so little water, I don't know why industrial installations don't do it.
Additionally power stations use steam turbines which require a lot of water. Some cooling water for misters would probably be a rounding error.
Seriously: Maybe residue wouldn't be an issue if it was never allowed to dry, but the corrosion-proof construction, drainage system, and pumping costs would be considerable. Then there's the 100 problems we're not aware of yet...
I think this will not be a problem, as the salt would be continuously washed away with new water. But the corrosion would be a problem indeed.
Maybe some plastic/epoxy/glass casing would help, but it might also hinder recyclability.
https://www.newindianexpress.com/states/kerala/2021/dec/13/c...
The plants under the panels also reduces the heat under the panels and thus increases the efficiency of power generation.
This can be a nice way of getting additional income from the land and also tackles the problem of plants growing under the panels.
https://www.newindianexpress.com/states/kerala/2021/dec/13/c...
Sounds like a job for center-pivot irrigation! Just choose a model that can rotate at 2 revolutions per hour.
I never really appreciated how brilliant these are until watching this video:
For large deployments of Earth-mounted PV you'll need a grid of drainage ponds to buffer runoff water, so you might draw from those. A control system would monitor temperature, PV output, and water turbidity.
The latter is important, since there's no sense dumping dirty water on the panels! Give the suspended solids time to settle out, or even add flocculants via a dispenser.
But obviously doing this repeatedly might not be good for it - naturally hail on a super hot day is rare.