Neighbouring shading effect on photovoltaic panel system: Its implication to green building certification scheme

Nowadays, photovoltaic (PV) system is one of the commonly adopted renewable energy systems. Many countries promote the application of PV system in buildings through green building certification schemes. On a building rooftop, there are various building facilities which may cast shadow on PV panels, resulting in reduction in electricity generation. Currently, there is rare attention to the neighbouring shading effect (NSE) on the performance of rooftop PV system. This study investigates the performance of PV system under NSE, using weather data of seven cities located at different geographical latitudes. These seven cities are Singapore (1.37 degrees N), Hong Kong (22.3 degrees N), Shanghai (31.17 degrees N), Beijing (39.8 degrees N), Harbin (45.72 degrees N), Washington, USA (38.98 degrees N) and London, UK (51.15 degrees N). By comparing the building cases with and without considering NSE, the results unveil a substantial percentage difference in PV electricity generation and energy payback time (EPBT) ranging from -12.62% to -28.34% and -14.43% to -39.55%, respectively. Moreover, it reveals the dependence of percentage difference in PV electricity generation and EPBT on the latitude of a city. For the current green building certification schemes, mandatory requirement to take NSE into account for assessing the performance of rooftop PV system is recommended. (C) 2022 Elsevier Ltd. All rights reserved.