Think of the children
Nuclear is not the way to go. There is already more than enough energy to meet our planet's needs coming from another source. It'll just take a little elbow grease.
No matter which form of power generation is chosen, ultimately it's all about electricity.
Given enough scale, both wind and sea-based forms would probably be detrimental. Who knows what all those ugly turbines would eventually do to global wind patterns. Who knows what all those undersea inertia-transferring gadgets will eventually do to our tides.
Solar - as we know it today - is also not the way to go. Panels everywhere. Too inefficient. Too much atmospheric dissipation.
Since we're going to spend the money on *some* technology, rather than billions upon billions more to "perfect" nuclear energy, let's get two things working:
1) Space Elevators.
2) Wireless transmission of electricity.
Artsutanov came up with the idea for #1 in 1960, and besides other still fictional tales, it was used to great effect twenty years later in Clarke's "Fountains of Paradise".
Tesla never did quite get #2 working, but had it not been for his spat with George Westinghouse, many things may have turned out differently for him, and us.
The solar collectors would live tethered to the space end of the elevator, adding mass to help hold it up, and out of the way of that pesky atmosphere. Need it to be a few miles across? No problem! Plenty of room up there. Put one atop every elevator; in aggregate, more than enough to power the planet's needs.
The resulting electricity would augment the energy needs of the elevator cars (offsetting the extra energy needed for mass going up, if there's not a corresponding amount coming down), but its primary task would be to travel part-way down the shaft, then beamed 'round the world, as Tesla envisioned.
Neither technology is quite within our grasp today, but if we don't start working on it, we'll never get to enjoy it down the road.