How much can dirt reduce solar panel output?
Estimates of global airborne particle deposition (Seinfeld and Pandis: "Atmospheric Chemistry and Physics") show average rates of over 26 kg/m²/yr.
We have found over 50 studies from around the world on the effects of dust on solar panel efficiency.
At right is a map that depicts the locations and results of some of these studies.
The studies also showed that to keep losses below 3%, weekly cleaning was essential.