I think this is pretty cool, but several questions spring to mind which I haven't found good answers for.

The first is what sort of density can you get out of these? How many per acre/hectare? 1? 3? California has a number of wind installations and some of them are pretty dense [1].

The second is what sort of radar signature does this thing have? Probably not a navigation hazard but should be interesting on the weather doppler display.

[1] http://www.jamielaval.com/Images2011/Journal/Tehachapi_windm...