I've installed more Solar panel arrays than I can count. Both at work on mountain top repeater sites and on MANY RVs. I purchased truck loads of used panels when they closed the HUGHE Carrizo Plains Solar generating facility in So Cal. I then resold them as an installed package on house boats and RVs. Got them dirt cheap and sold the arrays cheap. In my opinion, it is simply no issue as to whether to mount them FLAT on the roof, or use them in a portable way. It is true that you can get the most out of a Solar panel if you mount it so that it can always face the sun. In the early days of my RV installations, I went to great measures to do just that. I mounted the panels on a motor drive platform and installed a servo system to track the sun. It worked great... but what experience taught me was to just add one more panel, (or get the next larger size) and mount them the easy way.... FLAT. The power that you loose by not going to the trouble and pain of mounting them so that they can always face the sun, can EASILY be made up by just installing a larger panel or an extra panel.
Just put them up there, use sealant and screw them down to the roof as close to the place you will drop down as possible. I usually use a vent pipe or the refrigerator vent.... which ever is closest to the fuse panel, (or in some cases, the batteries). Use the largest wire that you can work with, to decrease the voltage drop. I've use #10 stranded in most RV installations. By mounting your panels this way, you never have to worry about or mess with them again... other than occasionally cleaning them off. Out of sight, out of mind, and if you make the right selections, your won't have any more dead batteries.
Snakebite
