A study conducted at the University of Turku, Finland, investigated how household cleaning products affect the ability of solar panel glass to transmit light. The results of the study were presented at the 41st European Photovoltaic Solar Energy Conference and Exhibition and in the conference proceedings.
Small chance of tap water, high pressure hose because I am not climbing on the roof, that’s rather high and Im not interested in being high enough to leave an impact hole when I fall.