Jabarto
Emperor
Why not? They give you a good production bonus and they are the first power plant available.
I can sorta relate to this. They cause catastrophic amounts of pollution if you have coal and oil; In my last game with the Persians, I had all three Granary resources (Rice, Wheat, Corn), Fish, Clams, and every Market resource that raises health, in addition to the health bonus that the Persian Markets get. Furthermore I had environmentalism, public transportation, fresh water and 4 patches of forest in my capital, and the unhealthiness ratio was at something like 36:33. My factory + Coal plant was putting out nearly 10 pollution points on top of my 20ish population.