Calculates the wind speed at hub height.

The method specified by the parameter wind_speed_model is used.

Parameters:weather_df (pandas.DataFrame) – DataFrame with time series for wind speed wind_speed in m/s and roughness length roughness_length in m. The columns of the DataFrame are a MultiIndex where the first level contains the variable name (e.g. wind_speed) and the second level contains the height at which it applies (e.g. 10, if it was measured at a height of 10 m). See documentation of ModelChain.run_model() for an example on how to create the weather_df DataFrame.
Returns:Wind speed in m/s at hub height.
Return type:pandas.Series or numpy.array


If weather_df contains wind speeds at different heights the given wind speed(s) closest to the hub height are used.