If I have a choice I will park my trailer or van under the tree. Having solar panels permanently attached to the roof makes them less effective. Parks and mountains have trees and camping in wooded area is common unless you are in the desert. I decided that my van could use both, couple panels on the roof for convenience and couple portable panels to position where I want it. For this purpose I decided to build my own portable “suitcase”. Unlike commercially available systems I didn’t attach a charge controller to the panels. My plan is to have a higher end solar charge controller in the van handling both permanent roof panels and my portable system.