Hi , and am I being realistic?

[davidbrady]

Hi John,

The efficacy of rooftop solar power depends on how much you need to run your air conditioners. If you're comfortable outside, then you'll be comfortable inside w/o AC's assuming you can park in the shade with the windows open, interior ceiling fans running, and with the bus oriented to take advantage of outside breezes. This is a tall order but there are areas in the country where it works; i.e., the Bay Area, Ca for instance. In all other cases you'll need your air conditioners and you'll need at least two of them. They typically require around 2kW each. If you can completely line your roof top with the latest solar panels you may be able to fit fourteen 300W panels for a power output of around 4kW which sounds like it should handle two AC's but solar panels only produce power during daylight hours, only when not clouded over, and most efficiently when pointed directly at the sun. So on average your 4kW system is probably producing a long term daily power output of around 1kW (assuming 12 hrs of sunlight and factoring in clouds and the aperture angle of the panel), and all this is at the cost of $3K just for the panels. Usually running ACs means either connected to shore power or running the generator. Also, fourteen 300W panels weighs 850lbs not including mounts. From a vehicle driveability standpoint, you'll definitely feel 1000 lbs added to your rooftop - think upside down pendulum! I've seen bus owners lay their panels out on the ground, but in a campground environment space is restricted. All of this means solar panels in a bus application can only really provide a trickle current and function as a fair weather adjunct to genny power while boondocking, but cannot be counted on to power multiple air conditioners.