The reason that wind energy has exploded with installations all over the world since 2000 is that in many markets wind can generate electricity less expensively than oil and natural gas. The reason that wind electricity has become so inexpensive is that power output is proportional to the square of the diameter of the rotor and also to the cube of the wind speed. Wind is much faster as one goes higher above ground in any location. Little turbines are meaningless toys at best and diversion from real wind turbines that pose a real threat to the oil and coal economy at worst.

If one understands the importance of gigantic scale for turning wind into economic electricity it becomes obvious that the blades need to move in the plane of gravity as the rotors of the brilliant design of three bladed wind turbines do. One blade would be ideal in terms of angular momentum but when scale gets huge the asymmetry causes torque. Two blades also has torque problems because when one blade is at the highest position the other is at the lowest. The differential of wind speed between the lowest and highest position in two blade wind turbines causes torque in addition to the fact that the lower blade is in wind shadow from the tower causing more torque. So three blades becomes the ideal design.

I met MIT engineers that did not understand these elemental parameters for designing wind turbines so I am not impressed that rocket scientists do not get it either.

The secret of wind energy success is scaling up the blades it is not an issue of geometry or fancy shape.