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Wind power calculation

With nPro power generation profiles for wind turbines in hourly resolution can be generated. On this page it is documented how these are calculated.

How are wind power profiles calculated?

In nPro, the wind speed at hub height of the wind turbine is calculated in a first step. For this purpose, the power law according to Hellmann is used: $$w_\mathrm{hub} = w_\mathrm{ref} \left(\frac{h_\mathrm{hub}}{h_\mathrm{ref}}\right)^a$$ Here, \(w_\mathrm{hub}\) is the wind speed at hub height, \(w_\mathrm{ref}\) the measured wind speed, \(h_\mathrm{hub}\) the hub height, \(h_\mathrm{ref}\) the reference height at which the wind speed measurement took place, and \(a\) the Hellmann coefficient. In a second step, the generation power of the turbine is calculated with power curves from manufacturer data. In Table 1 the power curve of the wind turbine Enercon E141 is illustrated.

The nPro tool calculates for different wind turbine models the power generation profile with hourly resolution.
Annual energy yield of an ENERCON E115-EP3 turbine
Figure 1: Annual energy yield of an ENERCON E115-EP3 turbine for the two size classes 4.2 MW and 2.99 MW.
Table 1: Power curve of the wind turbine Enercon E141.
Wind speed at hub height Power generation
0 m/s 0 kW
1 m/s 0 kW
2 m/s 22 kW
3 m/s 104 kW
4 m/s 260 kW
5 m/s 523 kW
6 m/s 920 kW
7 m/s 1471 kW
8 m/s 2151 kW
9 m/s 2867 kW
10 m/s 3481 kW
11 m/s 3903 kW
12 m/s 4119 kW
13 m/s 4196 kW
14 m/s 4200 kW
... 4200 kW
25 m/s 4200 kW
25.1 m/s 0 kW

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