This guy wrote a GREAT book, and has this web site with all kinds of helpful info:
click.How much solar depends on (as others have noted) how much power you need/use. It also very much depends on how much you have in the way of batteries, for if you have more solar panels than you have batteries, you will find you can't use the power those panels produce, and if you have too few panels, you won't be able to keep the battery fully charged.
Spring for that guy's book. It is very well written, and easy to understand.
When my little 1800 watt inverter generator died last year, I went solar. I never expected to be able to run the AC, couldn't do that with that generator anyway. I've only one 80 Amp hour 12 volt battery on my TT, and it turns out that a single 100 watt solar panel is probably all that's needed to keep that battery charged, on average. But I plan to upgrade soon to a single 100 amp hour lithium battery, and that calls for two 100 watt panels. I find that those 2-100 watt panels turned into a dandy folding package that is easily portable. But that's as much as I'd want to have to schlep around.