Cleaned solar panels with deionized water and a waterfed Pole. I manually scrubbed all 25 solar panels several times then rinsed with deionized water. Even thourth it rained heavily multiple times 48 hours prior to me cleaning The solar panels were still dirty. Once I was done the customer's productivity was higher and there productivity was higher even on this cloudy day and the panels were squeaky clean. Completed promptly by our solar panel cleaning pros.