It is a resistance wind turbine, which relies on the difference between the windward surface resistance and the leeward surface resistance to obtain power. The greater the difference, the higher the efficiency (streamline and continuous shape to avoid air disturbance energy loss). The system has high stiffness and rotates The shaft is thin, the friction resistance (friction circle is small), its linear speed is always lower than the wind speed, the transmission inertia is small, and the speed stability is not good, which can be improved by a mechanical system similar to a flywheel. Efficiency is related to resistance area and surface smoothness.
The rotating axis of the vertical axis wind turbine is perpendicular to the ground, that is, vertically. The rotation plane is horizontal, so it can work regardless of the wind direction, no need to face the wind direction. The vertical blades create resistance against the wind to propel the wheel, much like a sail propels a boat. The blades on the impeller are movable, making it easy to adjust the angle to generate maximum driving force. There are also more advanced lift-type blades, which have an aircraft airfoil cross-section and use lift to push the impeller, which is more efficient.