I'm with ya Chowan.
Solar has it's place, and I think it might pay off for folks that mainly travel the southwest, where it's more often than not, sunny. Here in Michigan, it's rarely sunny ALL DAY LONG, and if the sun is out, it's low in the sky, so rooftop solar would need a good tilt, and then lay flat again in a few days when it comes to move to a new campsite. Maybe if I treated my RV more like a trailer park model, and left it somewhere for weeks/months on end, my thought would be different?
I use solar while I rv; in the form of ancient phytoplankton that's been crushed for millions of years and transformed into crude oil, refined into gasoline and used for internal combustion on my generators.