Reality: 2900W/120V = 24A AC, with losses that about 264A DC. You'll need lots of batteries and controllers or off grid controller setup. That's one hugh solar system for an RV.
It doesn't end there. There are controller and wiring losses and you only get the rated panel output at high noon, clear sky, panels aimed directly at the sun. Let's assume you get 70%: So 264/70% = 377A*14.4V charging = 5430W. So with 300W panels you'll need 18 very large 60 cell panels.
So just run your gen.
Why do you want to drill into the side and not the roof. There are already hundreds of holes in the roof in mfg. What's a few more? :h
Are we all having fun? :B :B :B