Are wind and solar really the world's energy future?

That's what this guy, Walter Kohn, Nobel winner in Chemistry, thinks. I have trouble figuring out how both of these sources, which are a) dependent on region, and b) dependent on atmospheric conditions, and in the case of solar c) dependent on what time of the day it is -- could be considered a reliable main energy source. He's thinking on the level of individual units; but that means he's not covering the industrial and transportation sectors.

Kohn says: "The global photovoltaic energy production increased by a factor of about 90 and wind energy by a factor of about 10 over the last decade. He expects vigorous growth of these two effectively inexhaustible energies to continue during the next decade and beyond, thereby leading to a new era, the SOL/WIND era, in human history, in which solar and wind energy have become the earth's dominant energy sources."

I don't think this is realistic. In fact, I think that it's wishful thinking by an old guy (albeit a smart guy) that won't be around to watch the generations of this century face the really hard choices.