It is obvious to anyone who has kept up with energy news that in the post peak-oil era there is no single or even combination of alternative technologies that can give us the amount of energy that we now get from oil.

The thing to remember, though, is that our current energy consumption patterns are very wasteful. We wind up spending a lot of energy for very little effect because the energy's so cheap that, in a simple-minded economic analysis, efficiency isn't economical. Focus more on efficiency and stop being so wasteful about energy use, and from the look of things, you can achieve a society that is sustainable and more pleasant to live in.