Self cleaning glass may be effective if installed vertically on buildings but possibly less effective when installed at, say, 30 degrees to the horizontal. The self cleaning aspect also needs a water flow (rain) to wash off airborne dust but bird shit isn't dust, it's an etching glue that sets hard on hot days!
Just consider how difficult it is to wash bird shit from a car if left to dry for a couple of days.
I've seen how much pigeon shit can be deposited in a loft during a two week period when they have gained access through a missing slate - believe me its a lot. If the person with the panels has a colony of pigeons his roof under the panels is likely to be white.