Can you explain why it needs ac to shock you ?
Dc current is actually more dangerous than ac when it comes to getting a shock .
This was explained to me in detail by an installer we do cleaning for, but only over the phone, so I didn't absorb it fully. I know that it is to do with needing a positive and a negative to get a shock. By removing the AC, you are removing one of those two elements. That's why you won't get a shock. There was more to it than that, but that is it in a nutshell. He is the electrician, solar panel installer and a designer and patent holder of solar panel add-ons, not me. Therefore, I don't lean upon my own understanding.

I know there are many who do not agree on this forum, but solar panel cleaning is a different kettle of fish to window cleaning. You MUST know what the risks are so that you can minimise them. If you do not know the risks, you should not be cleaning solar panels. An electrician or gas fitter must know their risks in order to minimise them. The risks associated with solar panel cleaning are just as real and are just as high. It pays to be informed and insured.