pvlib.temperature.sapm_cell_from_module#

pvlib.temperature.sapm_cell_from_module(module_temperature, poa_global, deltaT, irrad_ref=1000.0)[source]#

Calculate cell temperature from module temperature using the Sandia Array Performance Model.

See [1] for details on the Sandia Array Performance Model.

Parameters:

module_temperature (numeric) – Temperature of back of module surface [C].
poa_global (numeric) – Total incident irradiance [W/m^2].
deltaT (float) – Parameter \(\Delta T\) in (1) [C].
irrad_ref (float, default 1000) – Reference irradiance, parameter \(E_{0}\) in (2) [W/m^2].

Returns:

numeric, values in degrees C.

Notes

The model for cell temperature \(T_{C}\) is given by Eq. 12 in [1].

(1)#\[T_{C} = T_{m} + \frac{E}{E_{0}} \Delta T\]

The module back surface temperature \(T_{m}\) is implemented in sapm_module().

Model parameters depend both on the module construction and its mounting. Parameter sets are provided in [1] for representative modules and mounting, and are coded for convenience in TEMPERATURE_MODEL_PARAMETERS.

Module	Mounting	a	b	\(\Delta T [C]\)
glass/glass	open rack	-3.47	-0.0594	3
glass/glass	close mount	-2.98	-0.0471	1
glass/polymer	open rack	-3.56	-0.075	3
glass/polymer	insulated back	-2.81	-0.0455	0

Mounting cases can be described in terms of air flow across and around the rear-facing surface of the module:

“open rack” refers to mounting that allows relatively free air flow. This case is typical of ground-mounted systems on fixed racking or single axis trackers.
“close mount” refers to limited or restricted air flow. This case is typical of roof-mounted systems with some gap behind the module.
“insulated back” refers to systems with no air flow contacting the rear surface of the module. This case is typical of building-integrated PV systems, or systems laid flat on a ground surface.

References