Decoupling of global emissions and economic growth confirmed

[Wyatt earp]

I wonder how come they only use three blades on a wind mill?

Wouldn't four be better?

How about 12?

Actually, the optimum is one. Even numbers of blades lead to greater resonance reinforcements. More noise. Less efficient transfer (from wind to generator)

Seems like it would be unbalanced with one. But the rest you stated makes sense.

 

[Crick]

Few single-bladed turbines have been made but they simply use a counterweight to balance with the blade.