pvlib.pvsystem.sapm#

pvlib.pvsystem.sapm(effective_irradiance, temp_cell, module, *, temperature_ref=25, irradiance_ref=1000)[source]#

The Sandia PV Array Performance Model (SAPM) generates 5 points on a PV module’s I-V curve (Voc, Isc, Ix, Ixx, Vmp/Imp) according to SAND2004-3535. Assumes a reference cell temperature of 25°C.

Parameters:

effective_irradiance (numeric) – Irradiance reaching the module’s cells, after reflections and adjustment for spectrum. [Wm⁻²]
temp_cell (numeric) – Cell temperature [°C].
module (dict-like) – A dict or Series defining the SAPM parameters. See the notes section for more details.
temperature_ref (numeric, optional) – Reference temperature [°C]
irradiance_ref (numeric, optional) – Reference irradiance [Wm⁻²]

Returns:

A DataFrame with the columns –

i_sc : Short-circuit current (A)
i_mp : Current at the maximum-power point (A)
v_oc : Open-circuit voltage (V)
v_mp : Voltage at maximum-power point (V)
p_mp : Power at maximum-power point (W)
i_x : Current at module V = 0.5Voc, defines 4th point on I-V curve for modeling curve shape. Omitted if IXO, C4, and C5 parameters are not supplied.
i_xx : Current at module V = 0.5(Voc+Vmp), defines 5th point on I-V curve for modeling curve shape. Omitted if IXXO, C6, and C7 parameters are not supplied.

Notes

The Sandia module database contains parameter values for a limited set of modules. The CEC module database does not contain these parameters. Both databases can be accessed using retrieve_sam(). The full list of SAPM parameters is presented in the table below. Those that are required in the module parameter to run this model are as follows:

C0, C1, C2, C3
Isco
Impo
Voco
Vmpo
Aisc
Aimp
Bvoco
Mbvoc
Bvmpo
Mbvmp
N
Cells_in_series

Key	Description
A0-A4	The airmass coefficients used in calculating effective irradiance
B0-B5	The angle of incidence coefficients used in calculating effective irradiance
C0-C7	The empirically determined coefficients relating Imp, Vmp, Ix, and Ixx to effective irradiance
Isco	Short circuit current at reference condition (amps)
Impo	Maximum power current at reference condition (amps)
Voco	Open circuit voltage at reference condition (amps)
Vmpo	Maximum power voltage at reference condition (amps)
Aisc	Short circuit current temperature coefficient at reference condition (1/°C)
Aimp	Maximum power current temperature coefficient at reference condition (1/°C)
Bvoco	Open circuit voltage temperature coefficient at reference condition (V/°C)
Mbvoc	Coefficient providing the irradiance dependence for the BetaVoc temperature coefficient at reference irradiance (V/°C)
Bvmpo	Maximum power voltage temperature coefficient at reference condition
Mbvmp	Coefficient providing the irradiance dependence for the BetaVmp temperature coefficient at reference irradiance (V/°C)
N	Empirically determined “diode factor” (dimensionless)
Cells_in_Series	Number of cells in series in a module’s cell string(s)
IXO	Ix at reference conditions
IXXO	Ixx at reference conditions
FD	Fraction of diffuse irradiance used by module

References