Calculators › Renewables and on-site generation Wind energy from speed bins calculator
Wind energy from speed bins
Apply the cubic wind model separately to each below-limit speed bin before summing energy; cubing the mean speed loses the speed distribution. The 0.40 capture factor is a screening assumption.
Units IP (US) SI (metric)
E = 0.4 × K × A × ( v 1 3 × h 1 + v 2 3 × h 2 ) 1000 E = \frac{0.4 \times K \times A \times \left(v_{1}^{3} \times h_{1} + v_{2}^{3} \times h_{2}\right)}{1000} E = 1000 0.4 × K × A × ( v 1 3 × h 1 + v 2 3 × h 2 ) E = 0.4 × 0.5 × ρ × A × ( v 1 3 × h 1 + v 2 3 × h 2 ) 1000 E = \frac{0.4 \times 0.5 \times \rho \times A \times \left(v_{1}^{3} \times h_{1} + v_{2}^{3} \times h_{2}\right)}{1000} E = 1000 0.4 × 0.5 × ρ × A × ( v 1 3 × h 1 + v 2 3 × h 2 )
Calculator
Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.
Worked example
Given
K K K 0.00508 W/(ft²·mph³) A A A 600 ft² v 1 v_{1} v 1 11 mph h 1 h_{1} h 1 1,400 h v 2 v_{2} v 2 19 mph h 2 h_{2} h 2 600 h E = 0.4 × 0.00508 × 600 × ( 11 3 × 1400 + 19 3 × 600 ) 1000 ≈ 7 , 289 E = \frac{0.4 \times 0.00508 \times 600 \times \left({11}^{3} \times 1400 + {19}^{3} \times 600\right)}{1000} \approx 7{,}289 E = 1000 0.4 × 0.00508 × 600 × ( 11 3 × 1400 + 19 3 × 600 ) ≈ 7 , 289
Given
ρ \rho ρ 1.2 kg/m³ A A A 65 m² v 1 v_{1} v 1 5 m/s h 1 h_{1} h 1 1,600 h v 2 v_{2} v 2 9 m/s h 2 h_{2} h 2 400 h E = 0.4 × 0.5 × 1.2 × 65 × ( 5 3 × 1600 + 9 3 × 400 ) 1000 ≈ 7 , 669 E = \frac{0.4 \times 0.5 \times 1.2 \times 65 \times \left({5}^{3} \times 1600 + {9}^{3} \times 400\right)}{1000} \approx 7{,}669 E = 1000 0.4 × 0.5 × 1.2 × 65 × ( 5 3 × 1600 + 9 3 × 400 ) ≈ 7 , 669
Symbols and units
Symbol Meaning Unit
E E E electricity over the two bins kWh K K K imperial density and unit coefficient W/(ft²·mph³) A A A rotor swept area ft² v 1 v_{1} v 1 first bin wind speed mph h 1 h_{1} h 1 first bin duration h v 2 v_{2} v 2 second bin wind speed mph h 2 h_{2} h 2 second bin duration h
Symbol Meaning Unit
E E E electricity over the two bins kWh ρ \rho ρ air density for the specified wind condition kg/m³ A A A rotor swept area m² v 1 v_{1} v 1 first bin wind speed m/s h 1 h_{1} h 1 first bin duration h v 2 v_{2} v 2 second bin wind speed m/s h 2 h_{2} h 2 second bin duration h
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