Optimizing the annual energy yield of a residential bifacial photovoltaic system using response surface methodology

Abstract

This study investigates the impact of ground albedo, module spacing, height, and tilt angle on the annual energy output of a small-scale residential photovoltaic (PV) system. The study used response surface methodology (RSM) integrated with PVsyst simulation tool for the analysis. The results obtained from PVsyst are verified by comparing them with data from existing literature. Two significant contributions were demonstrated in this study: a parametric analysis that evaluates the influence of several parameters on the annual energy output, and a detailed statistical analysis that utilizes RSM with optimization. The central composite design with 30 runs was used for the experimental design. Within the tested ranges, the findings indicate that ground albedo, module spacing, and module tilt angle significantly affect annual energy generation. The RSM generated a statistical model that predicts the system's annual energy generation, with a determination coefficient (R2) of 0.99. Moreover, the RSM can identify the optimal values of the studied controllable parameters, which can lead to improved system performance and increased energy output. The optimization analysis reveals that the system's highest annual energy output is attained when the ground albedo is set at 0.82, the module spacing is 8.95 m, the module height is 1.35 m, and the module tilt angle is 35.7°. These parameters were determined based on the weather conditions in Sharjah, UAE. The findings reveal that the annual energy production of the tilted bifacial PV (T-BiPV's) improves by 12.4 %, when ground albedo is increased from 0.2 to 0.8. Also, the output increases by 69.47 % when spacing is increased from 2 m to 8 m. Additionally, increasing the height of the T-BiPV modules from 0.5 m to 2 m results in an increase in energy output by 5.63 %. This study can serve as a basis for further investigations into optimizing bifacial PV systems using RSM, particularly under restricted module spacing or when taking land cost into account in the optimization.