Energy Reports (Nov 2022)
Theoretical and experimental evaluation on the electrical properties of multi-junction solar cells in a reflective concentration photovoltaic system
Abstract
Solar photovoltaic systems represent an important technology for renewable energy utilization and have broad potential for application and development. However, the further development of solar photovoltaic systems is hindered by their higher generation costs. A high-concentration photovoltaic system (HCPVs) can use an inexpensive concentrator to replace solar cells; this, in turn, reduces the cost of electricity generation, because the solar cell requirement decreases for a given power. This study developed a mathematical model for multi-junction solar cell (MJSC) based on single-diode equivalent circuit, furthermore, an HCPVs with hyperboloid mirrors was established. The electrical properties for an MJSC module, including the short-circuit current (Isc), peak power (Pm), open-circuit voltage (Voc), fill factor (FF), and efficiency (η) were investigated at concentration ratios between 650 X and 800 X and direct solar radiation intensities between approximately 400 W/m2and 730 W/m2. Furthermore, the experimental results and theoretical values were comparatively analyzed. The results demonstrated that Isc, Voc, and Pmof MJSC module increased as the direct solar radiation raised. In contrast, the FF and η of an MJSC module decreased as the direct solar radiation raised. As the direct solar radiation intensity was 700 W/m2 and concentration ratio increased from 650 X to 800 X, Isc, Voc, and Pmincreased from 1.002 A to 1.243 A, 11.095 V to 11.158 V, and 9.466 W to 11.358 W, respectively. Conversely, the FF and η of the MJSC module decreased from 32.51 % to 31.33 % and 0.851 to 0.819, respectively. The tallied between the numerical and experimental results was evaluated, which indicated that root-mean-square error between the experimental and calculated values increased as the direct solar radiation increased.
Keywords
