How is power :lightening bolt: applied between coal, hydro, and nuclear plants? IOW, does a hydro plant replace a coacl plant with a nuclear plant replacing the hydro plant? Or, are the effects cumulative?

Also, how does the Three Gorges Dam wonder effect them? I never seem to notice a significant production boost from the TGD, even though it effects cities on a signle landmass.

They are definitely NOT cumulative.

I'm pretty sure the order is that the power comes from....

TGD (if you have it),
Hydro Plant,
Nuclear Plant,
Coal Plant.

You only get the health negative from Coal if you don't have any of the other plants.

Of that list, the one I'm most likely to be wrong about is the Nuclear Plant. It might take precedence to everything else. I've only built a couple of them, during one of my first games, and have never built one since.

From a game standpoint. If I think I can get TGD (meaning I have a Great Engineer or two standing around to build it), I'll just use that.

Otherwise, I build Coal Plants as soon as I can in all the non-river cities. The river cities build Hydro Plants when they become available.

But, if you've built a coal plant in a river city and then a hydro plant when it becomes available, is the coal plant "shut down?" You said there not cumulative, but what happens to the coal plant? Is it just there in the event you were to lose the hydro plant (how is another matter)?

But, if you've built a coal plant in a river city and then a hydro plant when it becomes available, is the coal plant "shut down?" You said there not cumulative, but what happens to the coal plant? Is it just there in the event you were to lose the hydro plant (how is another matter)?
This is correct - the coal plant remains dormant for the time you have hydro power, i.e. you do not get its :yuck: effect while you have hydro power. This is basically a backup for when you lose power from another source (now of course you won't necessarily lose the hydro plant, but it is well possible to lose the TGD (if someone captures it).
Power is not cumulative you either have it or not.