Not enough energy to go around...

Where will all the energy we need in the future come from? Maybe it won't!

So where will the extra energy come from? Relying on figures from the World Energy Assessment by the United Nations Development Program, Nocera looks at the maximum amounts of power that various non-fossil fuel sources might supply. Biomass could supply 7-10 TW of energy, but that is the equivalent of harvesting all current crops solely for energy. Nuclear could produce 8 TW which implies building 8000 new reactors over the 45 years at a rate of one new plant every two days. Wind would generate 2.1 TW if every site on the globe with class 3 winds or greater were occupied with windmills. Winds at a class 3 site blow at 11.5 miles per hour at 33 feet above the ground. And hydro-power could produce 0.7-2 TW if dams were placed on every untapped river on the earth. Nocera concludes, "The message is clear. The additional energy we need in 2050 over the current 13.5 TW base, is simply not attainable from long discussed sources—the global appetite for energy is simply too great." [More]

Sooner or later, the market will encourage us to lower energy consumption, and my bet is technology to trim energy use will be even hotter than technology to produce energy.