[cnvogel]

Given the total effort spent, I think adding a canister of fuel every two days is absolutely reasonable.

The additional complexity of solar or a few turbines would have caused that project to probably consume much more resources than (just guessing) one large car tank filling over the whole runtime.

Also: the generator probably is way overpowered to just charge the battery, must small ones have 1-2kW or so. Its consumption likely is dominated by whatever it needs during idling. So, a way to probably cut consumption in half would have been to just use two times the number of batteries and charge half as often.

Update: Based on http://powerequipment.honda.com/generators/models/eu2000i (first random find, and, yes, it's a 120V model for the US, but I'm only interested in the petrol consumption) it's probably even less fuel: tank is 1 galon (3.8l), enough for 3.4 hours @ 1.6kW or 8.1h @ 400W. Naively splitting between idle and delivered-power consumption, we get 0.25l/h idle and additional 0.54 l/kWh. So taking the numbers from the article (400W full power load which would deplete the batteries in 2W), it can't be more than maybe three/four litres every two days.

[chrlilje]

That is a very good guess for the fuel consumption! We use a Honda Eu10i generator that have a fuel tank size of 2.1 liter.

We (I) fill the generator and start it, and let it charge the batteries until it runs out of gas. We start the generator every day now to avoid running the batteries too low.

Batteries are 6 x 6 V AGM arranged in 6+6||6+6||6+6.

We did consider windpower, but it would have been quite a bit more complicated for our tiny budget. And we would have to have a plan for both days with no wind and days with storm.

My dream solution would be a bigger battery bank, and a generator that can start automatically when the battery voltage drops under a certain level. Add a huge fuel tank and it would have been able to run unvisited for weeks.