No, I will not elaborate.
Okay, I will elaborate a little. I hate disney movies, they're all slop, but I loved the last PotA trilogy (Rise, Dawn, War), in fact War is one of my favourite movies of all time. I was extremely concerned with the big mouse bought Fox that they would disneyfy PotA but Kingdom had similar vibes to the last trilogy and had some really lovely moments, e.g. the observatory scenes and any scene with Raka. Soundtrack was also nice. I liked it.
I mean they wanted to power the entire human civilization in SF; they were living inside an enormous skyscraper. Suspend your disbelief, it's an amazing trilogy.
You really don't need that much power. Especially for post apocalyptic society. They are so few people and surrounded by tons of infrastructure that was capable of supplying power for 500 times their population.
I didn't even mention solar power. There was a scene where they even had a small solar panel at their tent. Don't tell me they can't go collect solar panels from the rich folks homes in SF and the hills of the East Bay..