Show theoretical wind power and an adjusted scenario using entered air density, Cp, and efficiency.
Inputs and method
Swept area = π × (diameter/2)². Theoretical power = ½ × density × area × wind speed³. Adjusted power multiplies by entered Cp and efficiency. Wind-speed observations can be cross-checked with weather arithmetic such as the wind chill calculator.
All empirical factors, rates, percentages, clearances, product yields, and model values shown as inputs are scenario values supplied by you. Their source or measurement basis appears beside the inputs and result. Units remain visible, calculations use unrounded values, and rounding occurs only for display or a whole-package ceiling.
Interpreting the result
This does not estimate annual energy, siting suitability, rated output, or performance. Compare with a manufacturer power curve and rating. For a renewable-generation comparison, the solar panel energy scenario calculator models annual photovoltaic energy from user-entered specific yield.
Treat scenario ranges as sensitivity ranges, not confidence intervals. Check the factor’s version, geography, population or product, system boundary, and date before using the result. A numerical result does not establish code compliance, certification, safety, forecast accuracy, or model validity.
Validation and rounding
Blank required factors, invalid numbers, prohibited negatives, impossible relationships, and unsupported modes trigger a validation message. Results are rounded as stated; package quantities round up only after waste is applied.
Worked example
For density 1.225 kg/m³, 4 m diameter, and 8 m/s, area is 12.57 m² and theoretical power is 3.94 kW, about 5.3 mechanical horsepower (see the watts to mechanical horsepower calculator). Cp 0.35 and 90% efficiency give 1.24 kW; zero wind, Cp, or efficiency gives zero adjusted power.
Frequently asked question
Is this a turbine energy forecast? No. It is instantaneous ideal-power arithmetic adjusted by entered Cp and efficiency; use a power curve for rating work.
Keep the manufacturer or user basis with coefficients
Retain density, Cp, efficiency, wind, and their source/range basis together. Compare rotor diameter with those assumptions fixed. The result describes that wind scenario; it is not annual energy production and does not independently verify a turbine’s power curve.
Separate available wind power from your output assumptions
| Input group | Retain | What it contributes to this scenario |
|---|---|---|
| Wind and rotor | Wind speed and diameter | The entered flow and swept-area scenario |
| Air condition | Density and its source/basis | The density used in the power arithmetic |
| Capture and losses | Cp, efficiency, and source/version | The entered adjustment to theoretical power |
Test one group while keeping the others fixed. Keep uncertainty with the output; a result for one wind-speed scenario is different from an energy total accumulated across a year of conditions.
Sources
- U.S. DOE, “How Do Wind Turbines Work?” — current web edition; aerodynamic-power overview, accessed 2026-07-09. Route-specific boundary: context and terminology only; it does not supply an entered coefficient, uncertainty, recommendation, or approval.
- National Weather Service, “Density Altitude” — PDF edition; air-density variables and equations, accessed 2026-07-09. Route-specific boundary: context and terminology only; it does not supply an entered coefficient, uncertainty, recommendation, or approval.
- FAA, “Pilot’s Handbook of Aeronautical Knowledge” — current handbook edition; Chapter 12 atmospheric-properties passages, accessed 2026-07-09. Route-specific boundary: context and terminology only; it does not supply an entered coefficient, uncertainty, recommendation, or approval.