Why don't they put more blades and then add a variable transmission so that the blades spin slower, while producing more electricity?
Why only two blades? wouldn't 4 blades gather 2x the energy? 6 blades 3x, etc...
I would think that with the correct transmission configurations that they could produce still more energy while keeping the RPM's down to a slow enough speed to save all but the dumbest birds, bats, etc...
On a side note, I wonder how many raptors are killed on the interstate highway system. (I got an owl, and two hen pheasents under my wheels.) Almost got a turkey! Would like to get a few turkey buzzards.