How much energy could be generated worldwide using wind turbines? That’s the sort of back-of-the-envelope calculation that physicists love.

Estimates by scientists had put the generation rate at somewhere between 56 and 400 TW. To put that into perspective, a typical nuclear or fossil-fuel power plant churns out about 1 GW.

However, these calculations don’t tend to consider the impact of huge wind farms on the wind itself. Now, David Keith of Harvard University and Amanda Adams of the University of North Carolina have used a “mesoscale” weather model to do just that.

Their conclusion is that previous estimates of global wind capacity could be as much as 10 times too high.

I suppose this shouldn’t come as a surprise – if you extract vast amounts of energy from wind, you should expect some sort of modification to how the wind blows.

While current turbine deployments are nowhere near the size where we need to worry about how they affect wind and weather, some experts are calling for a future global wind-power total of about 10 TW. According to Keith, once global capacity exceeds a few terawatts, the effects on climate become significant and therefore must be considered in any large-scale deployment plan.