>I don't want to discount the rising importance of wind and solar. I do believe that with the ever decreasing costs these will become even more important, even

>I don't want to discount the rising importance of wind and solar. I do believe that with the ever decreasing costs these will become even more important, even critical, in the future. They simply won't completely replace some kind of combusted fuel. I completely disagree. There's no shortage of solar power hitting the earth at any given moment. The problem with these renewable sources is that they're non-constant. The solution is simple: storage. Obviously, that's easier said than done, but it is something that's being worked on. Once really good energy storage is in place, then the variable nature of solar/wind isn't too much of a problem any more. It's not here yet (we do have some battery storage, and for some time now we've had stuff like pumped hydroelectric), but it's coming.