Somethign you folk from North America will be familiar with.
There is a 12V light, fridge and occasional inverter to mains-voltage system with 12V "leisure" lead-acid battery and photovoltaic (PV) charger and charge-regulator.
For winter when our days are short and sun not bright - would it be an efficient solution to have a small gasoline engine running a 12V generator eg. from a car? Would be efficient to have a small engine which runs full-power for a shortish time - something like an hour? - then stops. Smallest Honda "GX" engine is 100cc. Small engine+12V-generator & battery is much more fuel-efficient than running a generator supplying power on-demand? Tempting thought is - that would happen when it is dark and *cold* - therefore if you coudl recover the waste heat of the generator engine it would be welcomed.
I have no knowledge of this - anyone want to get this going?
Regards, Rich Smith