Power Generation Performance Analysis of West Oriented Bifacial PV Systems on Gable Roofs under Different Installation

The global deployment of photovoltaic (PV) systems has accelerated to meet carbon neutrality goals by 2050.However, PV systems are strongly influenced by environmental factors such as solar irradiance and ambient temperature, resulting in variability in power generation, which may affect grid stability as PV penetration increases.In Korea, most PV systems are installed facing south to maximize energy yield, resulting in a concentration of power generation during the midday hours.To mitigate this temporal concentration, east-west-oriented PV systems have received increased attention.In building applications, PV modules are frequently installed on the same slope as gable roofs to maintain architectural aesthetics.However, most previous studies have focused on east-west PV systems on flat roofs, with limited experimental studies on bifacial PV systems installed on gable roofs.Therefore, this study experimentally investigated the performance characteristics of a west-oriented bifacial PV system installed on a gable roof using outdoor measurements.Roof albedo, module spacing, and module-roof distance were considered installation parameters.To evaluate the effects of these parameters, the front and rear plane-of-array irradiances and module performance were measured.The results indicate that roof albedo and module-roof distance are the dominant factors affecting the bifacial PV performance, whereas module spacing has a relatively minor influence.Increasing the module -roof distance also enhanced rear-side irradiance during the morning and afternoon periods, suggesting the potential for the temporal distribution of PV power generation.