At least for intermittent dust cleaning, one would assume most places that have solar panels would have a few dry days here and there.
I wonder if it would work for dry snow too. Ie when the flakes are falling that it could be repelled.
I was wondering too, if maybe under the right conditions, humidity sensors could trigger polarization of the glass surface followed by opposite polarization could potentially rid the surface of at least some of the dust. Some ionizing devices even produce a 'wind' of sorts.