Wind Turbine Calculator

P = 0.5 × air density × swept area × wind speed³ × power coefficient (Cp). Power scales with the cube of wind speed, so a 10% faster wind gives about 33% more power.

59.3% — the theoretical maximum fraction of wind energy any turbine can extract, derived from fluid dynamics. Modern horizontal-axis turbines typically achieve a real-world Cp of 0.35-0.45.

Because power scales with wind speed cubed, doubling wind speed multiplies power roughly eightfold — which is why hub height and site selection dominate turbine economics far more than turbine size alone.

Wake losses from nearby turbines, mechanical friction in the drivetrain, electrical losses in the generator and grid connection, and downtime for maintenance — combined these typically cut output by 10-20% below the Cp-limited figure.