Wind Energy Calculator — Formula
## How to Calculate Wind Energy Production
Wind turbine energy output depends on wind speed, rotor size, and efficiency.
### Formula
**Power (W) = 0.5 * Air Density * Swept Area * Wind Speed^3 * Efficiency**
**Swept Area = pi * (Diameter/2)^2**
**Annual Energy = Power * 8,760 hours * Capacity Factor**
The Betz limit caps theoretical efficiency at 59.3%. Modern turbines achieve about 40% (Cp = 0.4). Capacity factor accounts for variable wind conditions.
Wind turbine energy output depends on wind speed, rotor size, and efficiency.
### Formula
**Power (W) = 0.5 * Air Density * Swept Area * Wind Speed^3 * Efficiency**
**Swept Area = pi * (Diameter/2)^2**
**Annual Energy = Power * 8,760 hours * Capacity Factor**
The Betz limit caps theoretical efficiency at 59.3%. Modern turbines achieve about 40% (Cp = 0.4). Capacity factor accounts for variable wind conditions.
Exemplo Resolvido
An 80m rotor wind turbine in 7 m/s average wind with 35% capacity factor.
- Swept area: pi * (80/2)^2 = 5,027 m2
- Theoretical power: 0.5 * 1.225 * 5,027 * 7^3 * 0.4 = 423,096 W = 423 kW
- Annual energy: 423 * 8,760 * 0.35 = 1,296 MWh
- Homes powered: 1,296 / 10.5 = 123 homes