Theoretical study for different photovoltaic technologies under spectral irradiances in Malaysia

Abstract The outdoor performance of photovoltaic (PV) modules often diverges from that of under Air Mass (AM) 1.5G indoor test condition due to significant variation of operational conditions from one location to another attributed to the factors i.e. altitude, humidity, climate conditions, latitude etc. This study investigates the discrepancy in power conversion efficiency (PCE) of various PV modules between AM1.5G versus actual operational conditions. The prediction of annual yields for different PV modules is crucial for the users to estimate its return of investment from large scale solar power plant to residential PV system. Furthermore, the distribution of local spectral irradiances might be matched well with spectral responsivity of certain PV technologies. To address this issue, we developed a comprehensive theoretical modelling for forecasting the PCE of PV modules under Malaysian climate by selecting five sites: Bangi (Selangor), Bayan Lepas (Puala Penang), Jitra (Kedah), Setapak (Kuala Lumpur) and Sungai Long (Selangor). In this modelling, we found that fill factor versus open-circuit voltages of different intensities can provide more accurate curve fitting of empirical data, which can improve regression factor. The improved theoretical modelling is essential to optimize the PCE for a given location more precisely than the previous one. There are seven types of PV modules being selected in our case study, which are Monocrystalline (DelSolar), Polycrystalline (SolarTech), Thin Film CiGS (SolarTech), Mono PERC (Jinko), HJT (Panasonic), Bifacial Mono (Fortunes Solar) and IBC Mono (Spic Solar). The study shows that the Mono PERC module has the highest PCE at AM1.5G among all the seven types of PV modules that is 20.9%, followed by IBC Mono (20.7%), Bifacial Mono (20.0%), HJT (19.7%), Polycrystalline (16.5%), Monocrystalline (15.9%), Thin Film CiGs (13.9%). However, IBC Mono shows the best PCE under the actual solar spectrums in four locations of our case study except Sungai Long. Some of the PV modules such as polycrystalline shows lower PCE under actual solar spectrum as compared with the simulator. In overall, monocrystalline, Mono PERC, HJT, Bifacial Mono and IBC mono are favourable to local spectral irradiances.