Given the total effort spent, I think adding a canister of fuel every two days is absolutely reasonable.<p>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.<p>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.<p>Update: Based on <a href="http:&#x2F;&#x2F;powerequipment.honda.com&#x2F;generators&#x2F;models&#x2F;eu2000i" rel="nofollow">http:&#x2F;&#x2F;powerequipment.honda.com&#x2F;generators&#x2F;models&#x2F;eu2000i</a> (first random find, and, yes, it&#x27;s a 120V model for the US, but I&#x27;m only interested in the petrol consumption) it&#x27;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&#x2F;h idle and additional 0.54 l&#x2F;kWh. So taking the numbers from the article (400W full power load which would deplete the batteries in 2W), it can&#x27;t be more than maybe three&#x2F;four litres every two days.