pvlib.temperature.sapm_module#

pvlib.temperature.sapm_module(poa_global, temp_air, wind_speed, a, b)[source]#

Calculate module back surface temperature per the Sandia Array Performance Model.

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

Parameters:

poa_global (numeric) – Total incident irradiance [W/m^2].
temp_air (numeric) – Ambient dry bulb temperature [C].
wind_speed (numeric) – Wind speed at a height of 10 meters [m/s].
a (float) – Parameter \(a\) in (1).
b (float) – Parameter \(b\) in (1).

Returns:

numeric, values in degrees C.

Notes

The model for module temperature \(T_{m}\) is given by Eq. 11 in [1].

(1)#\[T_{m} = E \times \exp (a + b \times WS) + T_{a}\]

Inputs to the model are plane-of-array irradiance \(E\) (W/m2) and ambient air temperature \(T_{a}\) (C). Model outputs are surface temperature at the back of the module \(T_{m}\) and cell temperature \(T_{C}\). 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