The PV performance modeling application, PVsyst, implements a cell temperature model based on the Faiman module temperature model. The form of the model is:
where
is cell temperature (°C)
is ambient air temperature (°C)
is the absorption coefficient of the module (PVsyst default value is 0.9)
is the irradiance incident on the plane of the module or array (
)
is the efficiency of the PV module (PVsyst default is 0.1)
is the constant heat transfer component (
)
is the convective heat transfer component (
)
is wind speed (m/s)
PVsyst says little about what values to use for and
. Note that the current default values assume no dependance on wind speed (
)
- For free-standing arrays the current default is :
= 29
;
=
- For fully insulated arrays (close roof mount) the current default is:
= 15
;
=
PVsyst users can also enter a NOCT (Nominal Operating Collector Temperature) in place of values. The program then automatically calculates
values based on
and
.
Values for and
can be calculated which correspond to the reference parameters for the Sandia Cell Temperature Model. The PVsyst model can be approximated as
Similarly the Sandia Cell Temperature Model can be approximated as
Equating terms gives the following equations that relate the PVsyst cell temperature model parameters to the Sandia Cell Temperature Model parameters
: