Estimates the electrical power a wind turbine delivers at a given wind speed, from the standard wind power equation applied to the rotor's swept area, air density, the turbine's power coefficient (Cp — the fraction of available wind power the rotor extracts), and generator conversion efficiency.
Standards followed
Standard wind power equation: P = 0.5×ρ×A×v³×Cp×η_gen, A=π(D/2)²; Cp physically capped by the Betz limit of 0.593 (59.3%)
What it can do
- Swept rotor area from rotor diameter.
- Power output in W and kW from wind speed cubed, air density, Cp, and generator efficiency.
- Flags a Cp entry above the Betz limit as physically unrealistic.
- Grading band from LOW to VERY HIGH for a quick sense of scale.
Example problem
20m rotor diameter, 10 m/s wind speed, 1.225 kg/m³ air density, Cp=0.4, 95% generator efficiency.
- A = π×(10)² ≈ 314.16 m²
- P = 0.5×1.225×314.16×1000×0.4×0.95 ≈ 73,120 W
≈73.1 kW — NORMAL band.
Power output scales with the cube of wind speed, so accuracy is very sensitive to the wind speed input — use a representative average or a specific design wind speed, not a rough guess. Real turbines also apply a power curve (with cut-in, rated, and cut-out wind speeds) rather than the unbounded cubic relation used here, so this is most accurate near the turbine's rated wind speed, not at very low or very high speeds.