It is worth noting that the adopted calculation method apply
for components made of parallel surface, as a consequence it could
not be used for sample as S5, consisting of not parallel layers. The
PC layers have transversal support layers and this configuration
is not considered in the calculation method as well. Such devia-tion might not be critical for the optical properties, but it could
be for the determination the solar factor. The latter, as a matter of
fact, takes into account the amount of radiation absorbed by the
panels and emitted at longer waves towards the indoor and the
outdoor. The heat transfer due to the PC panel absorbed radiation
is influenced by the presence of the transversal support and need
to be taken into account, whereas the calculation methods does not
allow.