Generators are a huge pet peeve of mine. We have a large motorhome with a generator which we never use at festivals. The camper has 2 deep draw marine batteries that never seem to run down - lasts us for several days and we charge it again when we get home. Our stove and refrigerator run on propane. We don't go to festivals to watch TV or cook in the microwave (sometimes we forget to eat!) and we don't use the lights much. We use a propane lantern outside, the occasional light inside. The water systems use a pump that runs off the battery and that's about it.
I don't understand how some people can be so inconsiderate as to run their generators at all, much less into someone's yard spewing fumes and noise. It completely ruins jams.
When an obnoxious generator has been running for a long time and then shuts down, we do a LOUD round of applause and cheer wildly, so the perpetrator hopefully gets the idea. We've also tried speaking to the people nicely. Then speaking to the people running the event to get them to speak to the people. One time we just moved away. Most festivals we go to have certain hours when generators are allowed, but you know how some people are with following the rules. I totally agree with the idea of a separate area for people who want/need to run them.
Did use our generator on a cross-country trip when we stopped at a rest area in death valley. Had to!
Oh wait, we did use our generator at a festival once. It was a miserable, hot, humid scorcher and then a thunderstorm broke out. We took the opportunity of everyone being inside their campers to jump into ours, run the generator and run the A/C to cool off. And then we turned it off 1/2 hour later.