Wind Turbine Calculator
Calculate the swept area, rated power, and annual energy production for horizontal-axis wind turbines using wind speed, rotor diameter, and power coefficient assumptions.
Large utility turbines range from 90–140 m diameter.
Wind farm sites often average 6–9 m/s at hub height.
Adjust for altitude and temperature (sea level ≈ 1.225).
Modern turbines operate at Cp ≈ 0.40–0.48.
Accounts for gearbox and generator losses (typical 85–95%).
Use actual turbine availability; 8760 hours is the maximum.
Swept area
6,361.73 m²
Power output
505.2 kW
Annual energy
4,425,588.39 kWh
Capacity factor
100%
Households powered
413.61 homes
How to Use This Calculator
Collect wind resource data
Use wind maps or on-site measurements to determine average wind speed at hub height.
Select turbine parameters
Enter rotor diameter, power coefficient, and efficiency values from manufacturer specifications.
Review energy output
Compare the calculated annual energy against project goals to evaluate site suitability.
Formula
P = ½ ρ A Cp η v³
Energy = P × Operating Hours
Swept Area = π (D ÷ 2)²
Example: 90 m rotor, 7 m/s wind, Cp 0.42, efficiency 90% → Power ≈ 3.7 MW. Over 4000 operating hours, energy is ~15 GWh/year.
Increase air density for cold climates or decrease for high-altitude locations.
About the Wind Turbine Calculator
Wind energy depends on both atmospheric conditions and turbine design. This calculator gives a preliminary estimate of turbine output, enabling site comparisons and feasibility assessments without extensive simulation tools.
When to Use This Calculator
- Site screening: Filter potential wind farm locations.
- Academic projects: Demonstrate Betz law and turbine scaling effects.
- Community wind studies: Estimate energy impact for cooperatives.
- Technology comparisons: Evaluate different turbine models quickly.
Why Use Our Calculator?
- ✅ Physics-based: Implements standard wind power equations.
- ✅ Flexible inputs: Adjust density, efficiency, and wind speeds easily.
- ✅ Impact metrics: Converts energy output to household equivalents.
- ✅ Real-world ready: Aligns with manufacturer datasheet parameters.
Common Applications
Developers: Estimate performance before detailed computational modeling.
Students: Explore how rotor diameter scaling increases captured energy.
Policy analysts: Translate wind resource data into generation potential.
Tips for Best Results
- Use hub-height wind speed rather than ground-level measurements.
- Consider turbulence and wake effects for closely spaced turbines.
- Adjust operating hours to reflect turbine availability (typically 85–95%).
- Validate results against manufacturer power curves for accuracy.
Frequently Asked Questions
Does the calculator include cut-in or cut-out wind speeds?
No. It assumes continuous operation at the average wind speed. For detailed modeling, use turbine power curves with wind speed distributions.
What is the Betz limit?
The theoretical maximum power coefficient is 59.3%. The calculator caps Cp at 0.59 to respect this limit.
How do I account for wind shear?
Adjust average wind speed to hub height using a wind shear exponent or use measurements from a met mast at the same height.
Can this be used for vertical-axis turbines?
The formula applies to horizontal-axis turbines. For vertical-axis designs, use the specific power coefficient provided by the manufacturer.