A new paper by Amanda Adams and David Keith reports that once deployed on a large scale wind farms may generate even less power than previously thought.
Estimates of the global wind power resource over land range from 56 to 400 TW. Most estimates have implicitly assumed that extraction of wind energy does not alter large-scale winds enough to significantly limit wind power production. Estimates that ignore the effect of wind turbine drag on local winds have assumed that wind power production of 2–4 W/m2 can be sustained over large areas. New results from a mesoscale model suggest that wind power production is limited to about 1 W/m2 at wind farm scales larger than about 100 km2.
David Mackay, the chief scientist at DECC, has this to say about the UK's onshore wind resource:
...if we covered the windiest 10% of the country with windmills (delivering 2 W/m2), we would be able to generate 20 kWh/d per person, which is half of the power used by driving an average fossil-fuel car 50 km per day.
If the true figure is 1 W/m2, we could cover half the country with windmills and still not get enough energy for the average daily commute.
Wind power isn't looking any more sensible is it?