At the moment solar power and the other renewables are in thier infancy, in the years to come technological improvments will improve thier effeciency, as it stands we can only get a small amount of energy and its unpredictable so i would say its not viable currently, or is only viable for a small percentage of our energy production. As time goes on its the obvious choice though its an almost unlimited supply of power (sun wind and waves) which we don't have to start the process ourselves, just construct equipment that takes naturally occuring processes and harness thier energy.

For the time being i think nuclear energy is the way to go it is relatively safe aslong as regultions are in place, it seems much more effecient than fossil fuels and even if you don't believe in global warming burning fossil fuels does create some nasty pollution which nuclear doesn't. Of course the radioactive material has to be safely stored but i see this as less of a problem than pollutants in the atmosphere.