Calculators
Wind Turbine Power Curve Estimator
Annual Energy Production (AEP) from a simplified cubic / rated / cut-out power curve integrated against a Weibull wind-speed distribution per IEC 61400-12-1. SI units per the standard. Returns gross AEP, availability- and wake-adjusted net AEP, capacity factor, and rotor specific power.
Method: The power curve is approximated piece-wise — zero below cut-in, cubic P(v) = ½·ρ·Ar·v³·Cp from cut-in to rated, capped at Prated from rated to cut-out, zero above cut-out. The Weibull pdf is f(v) = (k/A)·(v/A)k−1·exp[−(v/A)k]. AEP is integrated as 8760·Σ P(vi)·f(vi)·Δv over v = 0…30 m/s with Δv = 1 m/s. Net AEP applies availability and wake/array losses. Betz limit Cp,max = 16/27 ≈ 0.593; modern utility turbines achieve peak Cp ≈ 0.45–0.50. Typical capacity factor for class-3 onshore is ≈ 0.30–0.40. Specific power 200–400 W/m² is typical (lower ⇒ higher capacity factor at low-wind sites). References: IEC 61400-12-1 Power performance measurements of electricity-producing wind turbines; Manwell, McGowan & Rogers, "Wind Energy Explained," 2nd ed., Wiley 2009; NREL/TP-500-36795 Wind Resource Assessment Handbook.
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