We run entirely on solar (about 350 watts of panels on our roof) and alternator power. For our usage (fridge, computer, lights, radio, etc) we have boundless power in the summer. Winter we end up needing to drive or idle for an hour or two every couple weeks if it has been cloudy (or frequent snow on the panels). 425ah of battery storage in the house bank.
We decided to forgo a generator because we could use the engine alternator if necessary, a generator would take more space, potentially a different source of fuel (hard to find small diesel generators), noise, exhaust, etc.
The largest improvement we made to our power system was installing a battery monitor and tracking down where all the power went (lead to extra fridge insulation, switches on the electronics that drew power even when off, etc). With these cheap changes we more than halfed our daily consumption with no impact on our lifestyle.
-e