Model Description

So far only two simple models are provided but there will improvements and a larger variety in future version hopefully with the help of the github community.

Wind Model

The wind model is a simple model based on the cp-values of a specific type of a wind turbine. The cp-values are provided by the manufacturer of the wind turbine as a list of cp-values for discrete wind speeds in steps of 0.5 or 1 m/s. The feedinlib makes an linear interpolation of these values to get a continuous cp-curve over the wind speeds.

P_{wpp}=\frac{1}{8}\cdot\rho_{air,hub}\cdot d_{rotor}^{2}\cdot\pi\cdot v_{wind,hub}^{3}\cdot cp\left(v_{wind,hub}\right)

with d_{rotor} the diameter of the rotor in meters, \rho_{air,hub} the density of the air at hub height, v_{wind,hub} the wind speed at hub height and cp the cp-values against the wind speed.

The wind speed at hub height is determined by the following equation, assuming a logarithmic wind profile.

v_{wind,hub}=v_{wind,data}\cdot\frac{\ln\left(\frac{h_{hub}}{z_{0}}\right)}{\ln\left(\frac{h_{wind,data}}{z_{0}}\right)}

with v_{wind,hub} the wind speed at the height of the weather model or measurement, h_{hub} the height of the hub and h_{wind,data} the height of the wind speed measurement or the height of the wind speed within the weather model.

The density of the air is calculated assuming a temperature gradient of -6.5 K/km and a pressure gradient of -1/8 hPa/m.

T_{hub}=T_{air, data}-0.0065\cdot\left(h_{hub}-h_{T,data}\right)

with T_{air, data} the temperature at the height of the weather model or measurement, h_{hub} the height of the hub and h_{T,Data} the height of temperature measurement or the height of the temperature within the weather model.

\rho_{air,hub}=\left(p_{data}/100-\left(h_{hub}-h_{p,data}\right)*\frac{1}{8}\right)/\left(2.8706\cdot T_{hub}\right)

with p_{data} the pressure at the height of the weather model or measurement, T_{hub} the temperature of the air at hub height, h_{hub} the height of the hub and h_{p,data} the height of pressure measurement or the height of pressure within the weather model.

Weather Data

The weather data manly used by the oemof developing group is the coastDat2 of the Helmholtz-Zentrum Geesthacht

http://wiki.coast.hzg.de/pages/viewpage.action?pageId=4751533

Due to licence problems we are not allowed to ship the dataset with the windpowerlib. Please contact the Helmholtz-Zentrum Geesthacht (HZG), the data set for Europe might be free for non commercial use.