Does money grow in wind farms?

"The wind turbines required in Britain alone, says Prof MacKay, would amount to about double the number of all turbines in the world. Even then, “the maximum plausible production from on-shore windmills is 20 kilowatt hours per day per person”, about a sixth of Britain’s actual consumption.

http://www.telegraph.co.uk/earth/7823681/Does-money-grow-in-wind-farms.html