Wind farms in the sky

The Economist magazine, in its Technology Quarterly supplement, has an article about a company Sky WindPower, based in San Diego, that wants to build wind farms in the sky (about 6 miles up where the winds are very strong).

Check out the company site for more details but here is a thumbnail of their design, there's a larger picture on their website.



The only thing I'm not clear about is how they'll avoid it being blown away or the cable connecting it to earth snapping! Neat idea though.