Vertical axis wind turbine models

The blades of this rotor are made of card crudely formed into a symmetrical aerofoil section. They are angled out from the hub at approximately 45 degrees. The blades will be operating at a range of relative wind speeds depending on the position along the blade. The geometry suggests that the air flow across the angled blade will be at a lower angle of attack compared to a perpendicular blade. The rotor should also work when the air flow is not directly on the side of the rotor.

This seems to start up and run more easily than the equivalent 2 blade H rotor and doesn't have the same vibration.