I'm not a big believer in post-apocalyptic planning or scenarios, and haven't seen the show, but wanted to point out one thing about generators: in the Pacific Northwest, nearly every gas station houses a pretty nice generator, used to pump gas after wind storms have knocked out electric power to run their pumps. You can actually track this by the very nice EPA (state or federal, I forget) website that lists locations they need a permit to host the generator on a commercial site for some reason I can't remember. No need really to map them though, so many gas vendors lost so much money after a storm a couple years ago that nearly every station has been upgraded since. For those more confident that we won't all descend to the post-apocalyptic scenario of hunter scavengers, generators connected to pumps preserve the availability of gas and diesel for the several days until new supplies can begin to roll into an area. It's a good example of a fairly inexpensive response to an irregular but real problem that typically comes from a natural disaster.

So why venture into a hospital, those generators are generally enormous and bolted down pretty good. A perfectly serviceable generator is probably down the street at your local gas station, and if you are a scavenger-thief in the after-world, you have even odds of being able to detach it, remove and take it somewhere else. And not that I advocate theft in any scenario, but post-apocalypse most of these generators are sitting on commercial properties that will have long been abandoned by any corporate presence - you would not be stealing a generator from some poor neighbor's backyard, used to keep his kids warm. Cuts down on the hero factor.

Your area of the country may vary.