Don't know what your solar panel is like but my panels came with 2" or so wide aluminum straps from one side to the other. I drilled these to fit two of the white plastic clamps (with screws to tighten/loosen) used to hold BBQs and the like. I can store the panel folded down or rotated 90* when I want to use it. When it is up I support it with a piece of 1 x 4 cedar with appropriate notches at top and bottom. I also have a light line that goes from the panel to the lower rail although I am not sure it does much.
At first I thought that I would fold the panels down a lot but they are up pretty much all the time unless we are coming into a dock.
Finished the circumnavigation in early February in Grenada. Have to work on a book project for the next several months so the boat will be waiting for next year.