We had a portable Renogy 100 watt solar suitcase on our 2013 Casita SD
Worked well with the Casita single 27 F
battery
Cost was about $350 for the
solar panel and wiring
We have dual factory 170 watt roof top solar panels on our 21 ft trailer with dual 6 volt batteries. Cost was around $2000
If we were to do it again , I would skip the roof top solar panels and just go with the plug and play portable solar
In the summer if you camp with utilities you don’t need solar and if you boondock camp you will want to camp in the shade and the rooftop solar units don’t work well in the shade
The rooftop solar on our 21 has too many roof penetrations for my liking , requires you to climb up on a ladder to constantly clean the panels and having wires strung all over the roof look like hell and make it difficult to clean / wax the trailer roof
The roof top solar may charge your trailer
battery while driving but so does your tow vehicle so I don’t see the big advantage
We plan on adding a Zamp port on our 21 ft trailer so we can utilize our Renogy portable solar panel