system
Given the following post, respond as if you're commenting on Reddit:
human
In zombie movies, the survivors are often left without any electricity (aside from generators), why is this? Do power companies require constant attention to continue functioning? Why don't they continue powering the city?

I can never stop noticing this in zombie movies/shows. Maybe it's just because there's no way for you to pay your power bill.
gpt
I work for a utility.  Coal plants have a stockpile of coal on hand and receive constant new supplies.  If no one is manning them though, they'll stop running pretty quick.  If trains stop coming they'll stop running in a matter of days.

Same with Natural Gas.

Nuclear could **possibly** run without human intervention for longer, but no where near as long as it runs now.  Maintenance is being done on nuclear plants all day every day.  that doesn't mean they are on the verge of blowing up of course, but they require attention and people to run them.

Hydro plants might actually be the best source for a while at least, ours are huge and are manned by only a handful of people that don't do very much.  It also can't supply a city at all though and if everything else went down it wouldn't be all that helpful either.

Making power is a gigantic operation.