A motorhome drawing electrical power from a battery bank, solar chargers, and a big engine-driven alternator would be my preference, avoiding the weight and maintenance issues of a separate genset, and hopefully, eliminating the LPG fueled systems. I know gas engines handle the task fairly well, they've been dealing with similar light loads for years, running air conditioning in urban traffic. Diesel has recently gotten more complicated with emissions control add-ons.
Limitations are really just cost, how much more will the consumer pay? There is a weight issue for the batteries, but that can be overcome with lithium technologies, which brings us right back to cost. Big alternators aren't that much more expensive, but batteries, clean inverters, and solar charging are, and a sub 3KW genset powered by a small, primitive air-cooled engine is relatively cheap, and compared to lead-acid batteries, lightweight.
The premium on the E-trek is what, about $10K? Which model do we compare it with?
