Guys FFS when it comes to cleaning solar panels its so FE, to do it right you must have proper access equipment, deep clean the panels manually and when they are dry apply some liquid glass technology which will keep the panels clean for 12 to 24 months also note the extra output in electricty generated will justify the extra charges applied and the next time you go to clean them the soils will just fall off with ease, google liquid glass technology and go with a company who will share everything you need to know about the cleaning and protection of solar panels, you then just need to explain to your custys your methods and all the features and benefits of the technology you are using to maintain their solar panels, companies promoting liquid glass technology will share some very interesting information with you that won't be shared on this forum and you will find it easy to explain to your custys the extra charges involved in having to hire access equipment to carry out this work properly, it is also going to be a huge market to get involved with for the future, just to finish again google liquid glass technology and talk to a few of the different manufacturers until you come across one that you feel comfortable working with.