ACTUAL AND SIMULATED TECHNICAL PERFORMANCE OF GRID-CONNECTED PHOTOVOLTAIC SYSTEMS WITH ASSESSMENT OF THERMAL LOSS IN TROPICAL RAINFOREST CLIMATE

The growing utilization of photovoltaic (PV) systems has driven the development of software simulation tools to improve the design and performance of such systems. However, the persistent challenge is the discrepancies between simulated and actual system performance. This study evaluated the technical performance of retrofitted grid-connected PV (GCPV) systems, focusing on performance ratio (PR) under tropical climate condition. Since previous studies have revealed that thermal loss accounts for up to 14% of the total system loss, this study has analysed the actual and PVsyst simulated thermal loss in relation to PR, for three GCPV systems in Malaysia. From the analysis, a significant discrepancy was found between the actual and simulated annual PR with mean bias error (MBE) of -7.9%, -13.7%, and -11.4% for systems A, B, and C, respectively. This discrepancy was attributed to the overestimation of thermal loss in the simulations. Specifically, the actual thermal loss values for systems A, B, and C were 8.0%, 6.0%, and 6.4%, respectively, while the simulated thermal losses were higher, ranging from 11.5% to 11.7%. These findings imply a range of deviation between 3.7% up to 5.7% between actual and simulated thermal loss. Consequently, these findings have highlighted the need to refine the thermal loss estimation in PVsyst simulations, considering the specific mounting types under tropical climate environment. The refinement will lead to improve the accuracy of the simulated PR, whilst assisting GCPV system designers to accurately predict the system performance with higher acceptance commercially.