Esther Magadley *, Ragheb Kabha, Ibrahim Yehia

This study investigated the effect of solar incidence angles and irradiance intensity on two commercially
available semi-transparent organic photovoltaics panels. The results of electrical measurements taken for the panels at different solar incidence angles and in sunny and overcast conditions are presented. This data is compared to diurnal data of the same panels on a frame at 30 tilt facing south.

It was found that the panels behaved very differently under different solar incidence angles and
irradiance conditions. Panel A had high absorption from the underside of the panel, whereas panel B did
not. Panel A efficiency and fill factor values were highest under lower irradiance and panel B efficiency
was highest under higher irradiance.

In sunny conditions, panel A efficiencies and fill factors increased with increasing solar incidence angles, indicating a higher absorption of the panel in lower irradiance. Panel B fill factor reduced, efficiency remained constant, and % transmittance reduced with increased solar incidence angles, indicating reflected irradiance increased with increasing q. Diurnal measurements showed that for both panels, efficiency and fill factor were higher in the morning compared to the afternoon with the same incident irradiance levels, indicating an overnight recovery phenomenon.