I can see that if you want to beeline to Hoover, you can bypass coals, with careful planning, maybe except for the city that will build the hoover. Upping the pollution 2-4 isn't that bad, IMHO.
Killer is right, you might be throwing shields "out the window". You will have to do careful planning for this scenario, not that it's really difficult, but the hoover is an 800 shield wonder, whereas coal plants are 160 shields (I'd add to Alc0p0pz's summary that coal plants are the cheapest, at 160 shields).
He's also assuming that he wins the Hoover race. I guess that's fair against this generation of AI, though I would not assume that in communist governments or multiplayer, but we can save that argument for another thread.
Originally posted by BridgeBoy
Even land-locked cities on different continent from Hoover...I wait for solar plants.
Solar plants arrive a full age after coal is found and they cost twice as many shields to produce. I'd suggest, even if you will build solars to reduce pollution, go for the coal first to make up for the lost time and to make building the solar plants faster:
If you had a 20-shield city & took 8 turns to build a coal plant, you'd have a 30-shield city (50% increase?). You could build a worker in 1 turn (if you don't have enough already to clean up pollution). How many turns would you be away from solar power? Well, depends on your tech rate, difficulty, what you already have, but I think you will probably be at least 10-12 techs away mimimum.
Let's say that represents 40 turns, for example. I have no idea how good an estimate that is, but you get 10 bonus shields per turn for 400 shields.
Your coal plant city will take 11 turns to build the solar plant (320 shields) while without, you will take 16 turns. The 8 turns it took you to build the coal are almost paid for here. Furthermore, you're gaining no extra production, just a reduction by 2 in pollution.
I think coal before solar makes good sense. The argument against a 240-shield hydro for cities with rivers would not be as convincing, I think, but might work out.