def calc_asue_el_th_ratio(th_power):
    """
    Estimate Stromkennzahl according to ASUE 2015 data sets

    Parameters
    ----------
    th_power : float
        Thermal power in Watt

    Returns
    -------
    el_th_ratio : float
        Current el. to th. power ratio (Stromkennzahl)
    """

    el_th_ratio = 0.0799 * th_power ** 0.1783

    return el_th_ratio