Wind Park Performance Analysis

Location

Name

Mean wind speed v_m

m/s

Mean air density ρ

kg/m³

Windpark

Wind power plant

Nominal power P_N

Rotor diameter d_rotor

Number of turbines n

Park efficiency η_Feld

Availability η_V

Economic Parameters

Investment cost

€/kW

O&M cost

%/a of investment

Plant operating life

years

Interest rate

Wind Power Plant Characteristics

Grafiktool: Highcharts.com

Wind Power Plant Parameters

1 m/s

2 m/s

3 m/s

4 m/s

5 m/s

6 m/s

7 m/s

8 m/s

9 m/s

10 m/s

11 m/s

12 m/s

13 m/s

14 m/s

15 m/s

16 m/s

17 m/s

18 m/s

19 m/s

20 m/s

21 m/s

22 m/s

23 m/s

24 m/s

25 m/s

26 m/s

27 m/s

28 m/s

29 m/s

30 m/s

Info: Wind Speed

For the calculations of the wind park performance analysis the mean wind speed in hub height is needed. If wind speed is only given in another measurement height, it can be converted to the hub height using the roughness length.

height h₁ above ground

roughness length z₀

wind speed v₁ in h₁

m/s

hub height h₂

wind speed. v₂ in h₂

m/s

Formula used for the calculations:
v₂ = v₁ · ln (h₂/z₀) / ln (h₁/z₀)

Info: Air Density

For the calculation of the power coefficient (amount of wind energy used by the converter) the mean air density is needed. The air density is dependent on the ambient temperature and the air pressure. Air pressure and density decrease with the height above sea level. In this form you can estimate the parameters.

Height h above NN

Air temperature ϑ

°C

Air pressure p

hPa

Air density ρ

kg/m³

Formulas used for the calculations:
p = 1013 hPa · exp (-h / 8005 m)
ρ = p / 287 J/(kgK) / (273,15 K + ϑ)

Info: Park Efficiency

In a wind park the wind converters can block the wind from each other. That reduces the amount of wind energy available to the respective converters. This reduction can be considered by the field efficiency. A real estimation of the field efficiency is complicated and cannot be done here. Nevertheless, you can estimate the efficiency for the calculations.

Info: Availability

Faults and maintenance work can result in the failure of some wind converters for certain time periods. Planning errors, a wrong estimated wind speed or other problems also can cause a reduced output. All these effects can be considered by the availability parameter.

Explanation of Calculation

distribution:
h(v) = π/2 · v / (v_m²) · exp (-π/4·(v/v_m)²)

Power coefficient:
c_p = 2 · P_el / (ρ · A_rotor · v³)

Mean power:
P_m = η_Feld · η_V · Σ_i ( P(v_i) · h(v_i) )

Annual generation:
E_a = P_m · 8760 h

Full load hours:
h_{full load} = P_m / P_nenn · 8760 h

Attention: This performance analysis is only a rough estimation that cannot replace a detailed planning and analysis. No responsibility is taken for the correctness of this information.
Detailed information about the calculation and simulation of wind energy converters can be found in the specialists book Understanding Renewable Energy Systems .