Nuclear Energy is the answer. Check this out: http://www.physorg.com/news145561984.html (PhysOrg.com) -- Underground nuclear power plants no bigger than a hot tub may soon provide electricity for communities around the world. Measuring about 1.5 meters across, the mini reactors can each power about 20,000 homes.
Longer term, I probably favor windpower stations scaled up to 20-50 MW per rotor and space based power, as developed privately. Short term, natural gas is the cleanest fossil fuel, *new* large scale PWR/BWR nuclear plants in the US are probably not cost competitive, e.g. $10,000-$15,000/kW installed. CO2 is not the problem to be dealt with, primarily the ash, sulfur and heavy metals are. I don't especially like coal power, especially old plants, but in a financially devastated US, that is the fossil fuel we in the US are going to depend on most to generate electricity for a few decades. Also I think the astrophysicists, climatologists and geologists who have pointed to earth's history, the "quieter sun" and solar interactions, who now predict *global cooling* starting now and bottoming in the next few decades, should be paid very close attention. Wringing 10%-15% more efficency out of a coal plant's emissions, say with a vortex generator, rather than 10%-15% *less* efficiency with CO2 capture, should be our goal. Update: The Hyperion design, using hydrogen gas as moderator and working fluid sounds interesting, but is still very early stage development. My previous interests have been in the pebble bed reactors using helium as the working fluid.
Clean coal could be a possibility. By sizing it properly, the sulphur is centrifuged out. Adding acohol (a renewable) gives a slurry that can be piped 4 times faster than water. You never need to separate the slurry but you do need to leave the ionized rods of the alcohol partially attached. The two products of the separation make the firing of the coal convert 5 times the energy in the steam production. Adding 4 times the current turbine capacity is just a matter of steel and copper. The stack CO 2 is merged with methane to produce a protein called urea. this means the alcohol loop of the renewables is back in the food web. The second product is a material that can be reformed into gasoline. And additional alcohol cen be added to it as well. This does produce some CO 2. The utilization of this fulfills a need of trees and crops. Strangely, there would not be enough produced to replace what was orginally captured by the raw materials used to make the original alcohol. There are some living organisms used in alcohol production: enzymes and yeast, for example. These little guys happen to love CO 2 as well. Drawing the flow sheets would take a minute of two but there is nothing new in any of the subprocesses. Also all the scientific data is readily available. The patents on the slurry piping turns happens to have expered at this point. If you look at some of the pipelines currently going in, you will see that often they just follow railroad right-of-ways. A lot of the flaring done for safety reason on coal fields is methane. acohol can be mixed with LNG as well. you can really burn rubber with that stuff. One of the patent holders also had the patents on the "socks" that are attached to irrigation elbows in the coarse grain irrigation. It all fits together and always has. So far the missing ingredient was capital. That is not a problem any more. Capital can be extracted from almost any market.
And the cycle turns - global cooling was the consensus view in the 70s as well. Science (as actually applied) isn't all that different from markets - opinions have a strong tendency to follow the dollars.