Why do wind turbines have three blades? © Getty Images

Why do wind turbines have three blades?

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Having too many blades is such a drag…

Asked by: Garry Hale, Swansea

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Having fewer blades reduces drag. But two-bladed turbines will wobble when they turn to face the wind. This is because their angular momentum in the vertical axis changes depending on whether the blades are vertical or horizontal. With three blades, the angular momentum stays constant because when one blade is up, the other two are pointing at an angle. So the turbine can rotate into the wind smoothly.


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Authors

luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.

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