GoKawiilResearch shows solar panel soiling losses vary widely, often modest in cost
Studies cited include IEA figures attributing 4-7% of global PV losses to soiling, an NREL study showing pollen cut output up to 15% at North Carolina sites, and UC San Diego research finding a 7.4% efficiency drop after 145 rain-free days. A YouTube test of three panels showed cleaning gains ranging from about 2.4% to 13.4%, while a UC San Diego calculation found cleaning a 5kW home system mid-drought would add only about $20 worth of electricity.