The "only" thing that that specificially concerns me, is there is no output/cost or output/wind speed charts for there design. Every couple months you will see a new company pop up that claims to have a VAWT that is better in every way than a HAWT, and then you don't hear anything else from them. While I am not here to bash VAWTs, as far as materials and cost in, compared to output, I have not been convinced of any VAWTs econimics yet.
Also the fact that they say that HAWTs need unidirectional is also a little fishy.