A new study demonstrates that it would be possible to generate global energy needs from wind power alone.
This comes from a Harvard study published in PNAS (the Proceedings of the US National Academy of Sciences), and reported in New Scientist. Abstract available here; full study here.
The study collated wind data from the past 30 years, to produce a database of the best available global wind information, to a resolution of six hourly for areas down to 50 x 60 km.
The modelling suggests the top ten carbon polluters (bar Japan) could generate all projected electricity needs onshore, from existing technology.
The example given to fill US needs was two or three turbines per square kilometre over just 13% of the country.
I would, however, reiterate my reservations on the use of wind power, specifically for the effect that large-scale 'harvesting' can have on climate. The one study I found - again in PNAS - that does look at this issue concluded that the large-scale effects would be 'nonnegligible', as expected.
I've been signed up for electricity from 100% renewable sources since it was first offered over ten years ago. My current option is for 100% solar sources: a little more expensive again that general renewables, but this reflects my concern, and in particular that extracting energy from solar sources has the least impact - potentially positive, in fact. This may be rather aspirational if wind harvesting is currently negligible - as it is - but one must look to, and build for, the future.