I LIKE your idea of potentially replacing the generator with a bank of batteries: assuming that you could make them plenty large for storage, yet light enough to keep the rig from tipping over...
You'd need a whole lot of solar panels. Musk has got a factory in New York State, that is supposed to produce "solar shingles" for the housing industry.
There is probably a lot of useful technology available there!
Question: Are you planning to keep the traditional chassis powerplant for over the road usage?