Wind Turbine Power Output Calculator

Wind turbines extract kinetic energy from moving air. The power available in the wind increases with the cube of wind speed — doubling wind speed gives 8x more power.

Power equation: P = 0.5 × rho × Cp × A × v³

Where:

• rho = air density (1.225 kg/m³ at sea level, 15°C)
• Cp = power coefficient (max theoretical 0.593 — the Betz limit; real turbines: 0.35–0.45)
• A = swept rotor area = pi × r² (r = rotor radius)
• v = wind speed (m/s)

Betz Limit: No turbine can extract more than 59.3% of the wind’s kinetic energy — this is a theoretical maximum. Real turbines achieve 35–45%.

Typical home wind turbines:

• Rotor diameter 1 m (micro): 50–150 W at 10 m/s
• Rotor diameter 2 m (small): 300–600 W at 10 m/s
• Rotor diameter 5 m (medium): 2–4 kW at 10 m/s
• Rotor diameter 10 m (large): 8–15 kW at 10 m/s

Wind speed guide:

• 3 m/s (light breeze): barely enough to spin most turbines
• 5 m/s (gentle breeze): useful energy starts here
• 7 m/s (moderate): good production
• 10 m/s (fresh breeze): rated power for most small turbines
• 12+ m/s: diminishing gains, most turbines feather blades for protection

Annual output estimate: Annual kWh ≈ rated power (kW) × 2,000–3,500 hours (depending on site) Coastal / exposed hilltop sites: 3,000–4,000 full-load hours/year Inland / sheltered sites: 1,500–2,500 full-load hours/year