pvdeg.humidity.backsheet#

pvdeg.humidity.backsheet(rh_ambient, temp_ambient, temp_module, start=None, Po_b=None, Ea_p_b=None, backsheet_thickness=None, So_e=None, Ea_s_e=None, back_encap_thickness=None, backsheet='W017', encapsulant='W001')[source]#

Calculate the relative humidity in a solar module backsheet as timeseries. It assume a value that is the average of the RH of the backside encapsulant and the outside surface of the module.

Parameters:
  • rh_ambient (pandas series (float)) – The ambient outdoor environmnet relative humidity in (%) EXAMPLE: “50 = 50% NOT .5 = 50%”

  • temp_ambient (pandas series (float)) – The ambient outdoor environmnet temperature in Celsius

  • temp_module (list (float)) – The surface temperature in Celsius of the solar panel module “module temperature [°C]”

  • start (float) – Initial value of the Concentration of water in the encapsulant. by default, the function will use an equilibrium value as the first value

  • Po_b (float) – Water permeation rate prefactor [g·mm/m²/day]. The suggested value for PET W17 is Po = 1319534666.90318 [g·mm/m²/day].

  • Ea_p_b (float) – Backsheet permeation activation energy [kJ/mol] . For PET backsheet W017, Ea_p_b=55.4064573018373 [kJ/mol]

  • backsheet_thickness (float) – Thickness of the backsheet [mm]. The suggested value for a PET backsheet is 0.3 [mm]

  • So_e (float) – Encapsulant solubility prefactor in [g/cm³] So = 1.81390702[g/cm³] is the suggested value for EVA W001.

  • Ea_s_e (float) – Encapsulant solubility activation energy in [kJ/mol] Eas = 16.729[kJ/mol] is the suggested value for EVA W001.

  • back_encap_thickness (float) – Thickness of the backside encapsulant [mm]. The suggested value for EVA encapsulant is 0.46 mm.

  • backsheet (str) – This is the code number for the backsheet. The default is PET ‘W017’.

  • encapsulant (str) – This is the code number for the encapsulant. The default is EVA ‘W001’.

Returns:

rh_backsheet (float series or array) – relative humidity of the PV backsheet as a time-series [%]