Aerodynamic principles limit wind turbine blades to three

Wind turbines typically utilize three blades rather than more, despite the intuition that additional blades would capture more energy. This design choice is driven by aerodynamic laws, economic costs, noise reduction, and mechanical stability.

Unlike sails that block wind, turbine blades function like airplane wings, generating lift through pressure differentials. Adding too many blades creates turbulence, as trailing blades encounter the chaotic air vortices produced by preceding ones, significantly reducing lift efficiency. Furthermore, the Lanchester-Betz-Joukowsky law dictates a theoretical maximum energy extraction limit of 59.3% for any rotor.