I almost wrote that it depends on the use but I didn't want to make my comment too long. I can certainly see the need for a gas engine if you're traveling a long ways and away from civilization for days. I suppose portable solar panels and battery storage would work if you're traveling to a single campsite and are staying there for a while, but I'm not such a purist that I think that would be practical in most cases.
But for local work use around a property/ranch/farm, electric is ideal.