Comparative Study of Different Photovoltaic/Thermal Hybrid Configurations From Energetic and Exergetic Points of View: A Numerical Analysis

Abstract

At present, only 20 percent of the incident solar radiation on the photovoltaic module is converted into electricity with the remaining dissipated as heat. The heat accumulation on the photovoltaic modules affects the electricity conversion efficiency. The photovoltaic/thermal (PV/T) solar system is considered to be one of the most promising technologies, which is proficient in producing both electrical and thermal energies. In this paper, four different PV/T configurations are numerically investigated by considering different air cooling and glazing methods. A three-dimensional numerical model is validated with both the numerical and experimental results available in the previous literatures. The performance for a typical day in August under the ambient conditions of Beijing, China, is evaluated from the energetic and exergetic points of view. The results show that the thermal, electrical, energy, and exergy efficiencies are significantly higher for the double-pass configurations than those for the single pass with air gap configurations. For the double-pass single-glazed PV/T air collector, the average daily overall energy and exergy efficiencies are 85.06 and 13.92%, respectively. The overall energy and exergy efficiencies are increased by removing the bottom glass cover for both the single pass with air gap configuration and the double-pass configuration. The double-pass single-glazed configuration achieves the highest daily average energetic, exergetic, thermal, and electrical outputs among the proposed configurations. On contrary, the single-pass double glazed with air gap configuration exhibits the lowest thermal and electrical efficiencies.