God-Emperor
Deity
What's the best energy plant?
Hydro, if you can wait that long and the city is on a river. No pollution (but still the 2 unhealthiness from having power) and no chance of a meltdown.
Frequently coal will be the answer simply because it comes significantly earlier.
Nuclear is almost never the answer due to the meltdown issue.
The Three Gorges Dam is obviously the best, in some sense, as it gives you power everywhere on the continent. But it is late and expensive. It will suddenly remove the extra 2 unhealthiness from every city with a coal plant, remove the meltdown chance if you built any nuclear plants, provide power in all those cities that never built a power plant of any sort, and it will also provide power in newly conquered cities that lost their power plant when being acquired. However, if you spent the same amount of production on military units instead then you might be able to win the game using them.