pvlib.pvsystem.calcparams_pvsyst(effective_irradiance, temp_cell, alpha_sc, gamma_ref, mu_gamma, I_L_ref, I_o_ref, R_sh_ref, R_sh_0, R_s, cells_in_series, R_sh_exp=5.5, EgRef=1.121, irrad_ref=1000, temp_ref=25)[source]

Calculates five parameter values for the single diode equation at effective irradiance and cell temperature using the PVsyst v6 model described in [1,2,3]. The five values returned by calcparams_pvsyst can be used by singlediode to calculate an IV curve.

  • effective_irradiance (numeric) – The irradiance (W/m2) that is converted to photocurrent.

  • temp_cell (numeric) – The average cell temperature of cells within a module in C.

  • alpha_sc (float) – The short-circuit current temperature coefficient of the module in units of A/C.

  • gamma_ref (float) – The diode ideality factor

  • mu_gamma (float) – The temperature coefficient for the diode ideality factor, 1/K

  • I_L_ref (float) – The light-generated current (or photocurrent) at reference conditions, in amperes.

  • I_o_ref (float) – The dark or diode reverse saturation current at reference conditions, in amperes.

  • R_sh_ref (float) – The shunt resistance at reference conditions, in ohms.

  • R_sh_0 (float) – The shunt resistance at zero irradiance conditions, in ohms.

  • R_s (float) – The series resistance at reference conditions, in ohms.

  • cells_in_series (integer) – The number of cells connected in series.

  • R_sh_exp (float) – The exponent in the equation for shunt resistance, unitless. Defaults to 5.5.

  • EgRef (float) – The energy bandgap at reference temperature in units of eV. 1.121 eV for crystalline silicon. EgRef must be >0.

  • irrad_ref (float (optional, default=1000)) – Reference irradiance in W/m^2.

  • temp_ref (float (optional, default=25)) – Reference cell temperature in C.


  • Tuple of the following results

  • photocurrent (numeric) – Light-generated current in amperes

  • saturation_current (numeric) – Diode saturation current in amperes

  • resistance_series (float) – Series resistance in ohms

  • resistance_shunt (numeric) – Shunt resistance in ohms

  • nNsVth (numeric) – The product of the usual diode ideality factor (n, unitless), number of cells in series (Ns), and cell thermal voltage at specified effective irradiance and cell temperature.


[1] K. Sauer, T. Roessler, C. W. Hansen, Modeling the Irradiance and

Temperature Dependence of Photovoltaic Modules in PVsyst, IEEE Journal of Photovoltaics v5(1), January 2015.

[2] A. Mermoud, PV modules modelling, Presentation at the 2nd PV

Performance Modeling Workshop, Santa Clara, CA, May 2013

[3] A. Mermoud, T. Lejeune, Performance Assessment of a Simulation Model

for PV modules of any available technology, 25th European Photovoltaic Solar Energy Conference, Valencia, Spain, Sept. 2010