pvdeg.degradation.vantHoff_deg

pvdeg.degradation.vantHoff_deg(weather_df, meta, I_chamber, temp_chamber, poa=None, temp=None, p=0.5, Tf=1.41, temp_model='sapm', conf='open_rack_glass_polymer', wind_factor=0.33, irradiance_kwarg={}, model_kwarg={})

Calculate Van’t Hoff Irradiance Degradation acceleration factor.

In this calculation, the rate of degradation kinetics is calculated using the Van’t Hoff model.

Parameters:

• weather_df (pd.DataFrame) – DataFrame containing at least dni, dhi, ghi, temperature, wind_speed

• meta (dict) – Location meta-data containing at least latitude, longitude, altitude

• I_chamber (float) – Irradiance of Controlled Condition [W/m²]

• temp_chamber (float) – Reference temperature [°C] (“Chamber Temperature”)

• poa (pd.Series or pd.DataFrame, optional) – Series or DataFrame containing ‘poa_global’, Global Plane of Array Irradiance [W/m²]

• temp (pd.Series, optional) – Solar module temperature or Cell temperature [°C]. If not provided, it will be generated using the default parameters of pvdeg.temperature.cell

• p (float) – Fit parameter

• Tf (float) – Multiplier for the increase in degradation for every 10[°C] temperature increase

• temp_model ((str, optional)) – Specify which temperature model from pvlib to use. Current options:

• conf ((str)) –

  The configuration of the PV module architecture and mounting configuration. Currently only used for ‘sapm’ and ‘pvsys’. With different options for each.

  ’sapm’ options: open_rack_glass_polymer (default), open_rack_glass_glass, close_mount_glass_glass, insulated_back_glass_polymer

  ’pvsys’ options: freestanding, insulated

• wind_factor (float, optional) – Wind speed correction exponent to account for different wind speed measurement heights between weather database (e.g. NSRDB) and the temperature model (e.g. SAPM) The NSRDB provides calculations at 2 m (i.e module height) but SAPM uses a 10 m height. It is recommended that a power-law relationship between height and wind speed of 0.33 be used*. This results in a wind speed that is 1.7 times higher. It is acknowledged that this can vary significantly.

• irradiance_kwarg ((dict, optional)) – keyword argument dictionary used for the poa irradiance calculation. options: sol_position, tilt, azimuth, sky_model. See pvdeg.spectral.poa_irradiance.

• model_kwarg ((dict, optional)) – keyword argument dictionary used for the pvlib temperature model calculation. See https://pvlib-python.readthedocs.io/en/stable/reference/pv_modeling/temperature.html # noqa for more.

Returns:

accelerationFactor (float or pd.Series) – Degradation acceleration factor