A bifacial photovoltaic thermal system design with parameter optimization and performance beneficial validation

This study proposed a bifacial photovoltaic thermal system (BPV/T) design. The two quality properties of electrical and thermal efficiency are important characteristics in the overall performance of the BPV/T. The relationship of the important parameters, including collector material, number of collectors, diameter, storage tank volume/surface area ratio, mass flow rate, cycle temperature, and azimuth angle, with respect to the quality characteristic of the BPV/T system was discussed. The Taguchi Method was used for the experimental plan, and the Transient System Simulation (TRNSYS) software was applied for theoretical simulation. At the same time, the Main Effect Analysis (MEA) and Analysis of Variance (ANOVA) were combined to review the influence of setup parameters on the electrical and thermal efficiency. The single quality optimization setup parameter combinations were obtained. For objective multiple criteria analysis, the objective weights of electrical and thermal efficiency are obtained from the analytical data of Principal Component Analysis (PCA). Afterwards, the Elimination Et Choice Translating Reality (ELECTRE) will be employed to obtain the optimized parameter combinations for each season throughout the year. The practical validation is performed according to the multi quality optimization setup parameter combination. The maximum errors in both the electrical and thermal efficiency between practical validation and simulation test are smaller than 4.3%. Then, the economic and footprint analysis of the BPV/T system was compared with both 1 kW photovoltaic (PV) and photovoltaic thermal (PV/T) systems. Based on the 20-year warranty of the PV module, in terms of economic benefit, the BPV/T system is higher than the PV/T system by 18% and higher than PV by 460%. In terms of footprint analysis, BPV/T is less than PV and PV/T by 11%; however, the overall energy output per unit area of BPV/T is 20% and 210% higher than PV/T and PV, respectively. In the future, the optimized parameters and benefits analysis of the BPV/T system from this study will be further applied to the planning of solar energy technology as a point of reference for end users or industrial communities to accelerate the development of BPV/T for the renewable energy market.