Gentlemen, gentlemen. Let's all agree to disagree. Solar is good for some, not for others. I personally will not have it on my bus (the way I see it now at least.) I have some experience with solar and I'm not overly impressed just for the fact that you have to have large battery bank to do much of anything besides turn a light on. As we all know batteries are heavy, and when you add all that weight up, a gas/diesel generator would be lighter. Not to mention the room they take up, plus the real estate of the panels, charge controller, inverter, and wiring.
Something else to ponder... on a hot summer day, where would you park the bus where it would get the best charge? In direct sunlight. Where would be the worst place to park an all metal vehicle with lots of windows? In direct sunlight.
It's not for everyone but every situation/bus is different. Solar just may be the answer you're looking for. Or it may be you're kryptonite. Research, research, research. And if you chose solar, consult a professional electrician (or a few) to size your system accordingly. Do it once, do it right.