Has this been discussed already? Either way...
There's a reason that we're not using coal (or in the amount that you suggest). Although it is plentiful, it isn't as clean as solar, hydroelectric, or wind power. Not to mention that it won't last forever (that isn't to say that all resources will
last forever. Some just last longer than others).
So, in my opinion, using hydroelectric and solar power would be a very good choice. The sun is going to be around for a lot longer (around four billion years, if I'm correct), and the Earth's supply of water isn't going anywhere fast. If you put a solar panel on the top of every building, we'd be in a very good situation.
As for nuclear power, that should, in my opinion, take a back seat to sustainable, cleaner sources of power, such as solar, hydroelectric or wind.
I'm still waiting for the solar-powered/battery-charged car.