Wind Speed Energy Calculator

Calculator Inputs

Use the fields below to estimate wind power, turbine output, and energy over time. Results appear above this form after submission.

Wind Speed

Speed Unit

Rotor Diameter (m)

Air Density (kg/m³)

Power Coefficient Cp

Drivetrain Efficiency (%)

Generator Efficiency (%)

Availability (%)

Other Losses (%)

Operating Hours

Cut-in Speed (m/s)

Cut-out Speed (m/s)

Rated Power Limit (kW)

Profile Interval Hours

Optional Wind Speed Profile

This optional series helps estimate interval-based power and energy across changing wind conditions.

Wind Speed (m/s)	Rotor Diameter (m)	Cp	Net Power (kW)	Energy in 6 h (kWh)
5.00	18.00	0.40	5.827	34.962
8.00	18.00	0.40	23.867	143.203
12.00	18.00	0.40	80.552	483.311

Formula Used

1. Swept Area: A = π × (D / 2)²

2. Wind Power Density: P_d = 0.5 × ρ × v³

3. Available Wind Power: P_w = 0.5 × ρ × A × v³

4. Net Electrical Power: P_net = P_w × C_p × η_d × η_g × Availability × (1 - Losses)

5. Energy Output: E = P_net × time

The model also checks cut-in and cut-out speeds. Rated power can cap output when turbine capacity is limited.

How to Use This Calculator

Enter the site wind speed and choose its unit.
Provide turbine rotor diameter and local air density.
Set Cp, drivetrain efficiency, generator efficiency, and availability.
Enter other losses and selected operating hours.
Define cut-in and cut-out speeds in m/s.
Optionally enter a rated power limit for capped output.
Add a wind speed profile to simulate varying conditions.
Press the calculate button to view results, charts, and exports.

Frequently Asked Questions

1. What does this calculator estimate?

It estimates available wind power, net electrical power, and energy output using wind speed, rotor size, density, efficiency factors, and operating time.

2. Why is air density important?

Air density changes the amount of energy carried by wind. Colder or denser air increases power potential at the same wind speed.

3. What is the power coefficient?

The power coefficient represents how much wind power the rotor can capture. It stays below the Betz-limit-based practical maximum of 0.593.

4. Why does the model use cut-in and cut-out speeds?

Turbines do not produce useful output below cut-in speed. They also shut down above cut-out speed to protect components.

5. What does rated power limit do?

It caps the calculated output so the result does not exceed turbine nameplate capability. This creates more realistic production estimates.

6. Can I compare multiple wind conditions?

Yes. Enter a speed profile using commas, spaces, or line breaks. The calculator will estimate interval power and total profile energy.

7. What units should I use for cut-in and cut-out?

Those fields use m/s. They match standard turbine performance data and keep operating range checks consistent across all speed entries.

8. Is this suitable for final project design?

It works well for feasibility studies, planning, and education. Final design should also include turbulence, wake losses, controls, and certified power curves.