This estimator converts a micro wind turbine's annual energy into a capacity factor: the share of its maximum theoretical nameplate production that was actually delivered over the selected period. It can evaluate a measured year or a modeled production forecast, provided energy, rated power, and hours cover the same interval. Owners and analysts use capacity factor to compare performance across turbines of different sizes, check whether an output forecast is internally plausible, and summarize wind resource plus operational effects in one number. It reflects wind availability, the turbine power curve, shutdowns, maintenance, electrical losses, and curtailment together, so it does not diagnose the cause of low production. A leap year can use 8,784 hours; a standard year uses 8,760. The result should be compared only with projects that have similar site conditions, measurement boundaries, and loss treatment.
Use measured or forecast kWh at a clearly defined electrical boundary.
Enter the manufacturer's nameplate output in kW.
Use 8,760 for a standard full year or the exact hours for another complete interval.
This helps detect unit or period mistakes.
Compare it with the assumptions used for the same site and turbine, not an unrelated headline value.
Capacity factor (%) = Annual energy ÷ (Rated capacity × Period hours) × 100
Annual energy is in kWh, capacity in kW, and time in hours. The denominator is theoretical output at full nameplate power throughout the period.
Capacity factor condenses energy production relative to nameplate potential; it is not efficiency or operating-time percentage.
Results are planning estimates based on the values entered. Confirm equipment limits, site conditions, and project assumptions before making a purchase or investment decision.
8,865 kWh over 8,760 hours from a 5 kW micro wind turbine.
Maximum output = 5 × 8,760 = 43,800 kWh. Capacity factor = 8,865 ÷ 43,800 × 100 = 20.24%.
The turbine delivered 20.24% of continuous nameplate production, equivalent to 1.01 kW average power.
Not when energy and nameplate capacity use the same boundary and period. A value above 100% usually indicates a unit, time-period, or capacity entry error.
No. Efficiency compares energy conversion, while capacity factor compares delivered energy with continuous nameplate output over time.
Use the boundary that matches the rated capacity and stay consistent across comparisons. For grid-connected turbines, AC energy and AC nameplate rating are often the clearest pair.
Enter the exact hours covered by the energy measurement. Do not annualize energy and then leave partial-period hours in the denominator.
Weak winds, turbulence, outages, icing, curtailment, electrical losses, and an oversized nameplate rating can all contribute. The percentage alone cannot separate them.