An RV'r needs power. Yes, you can go for maybe two days with your standard two battery bank, but after that, you need an infusion of juice. It's one of three ways. Plug-in, generator or solar. Those that go for solar are usually boondocking types. Meaning we/they don't use campgrounds (or cg's without hook-ups) and prefer solar over generators.
There is no cheap ride on this stuff. Solar will cost you, as will a generator or you are limited to your camping spots. The more installation/wiring work you can do yourself the more you don't spend.
Gary Haupt