Wind Turbine Swept Area & Power Calculator

Wind Turbine Swept Area & Power Calculator

Estimate a wind turbine's theoretical power potential based on rotor size and wind conditions, applying the fundamental Betz limit.

Swept Area = ¤Ç x (Rotor Diameter / 2)┬▓
Betz-Limited Power = 0.5 x Air Density x Swept Area x Wind Speed┬│ x 0.593

Example

An 80m rotor diameter turbine, 10 m/s wind speed, standard air density:

Swept Area = 5,027 m┬▓ → ~1,825.7 kW Betz-limited theoretical power

What the Betz Limit Actually Is

The Betz limit is a fundamental physical law, derived from basic fluid dynamics, stating no wind turbine design can capture more than 59.3% of the kinetic energy in the wind passing through its rotor - this isn't an engineering limitation to be overcome, but a hard physical ceiling.

Why Wind Speed Matters So Much

Since power scales with wind speed cubed, even a modest increase in average wind speed at a site produces a dramatically larger increase in energy output - this is exactly why wind resource assessment and turbine siting focus so heavily on finding locations with consistently higher average wind speeds.