Seasonal experimental study of a hybrid photovoltaic-water/air solar wall system

Abstract

Traditional BIPVT systems are faced with the seasonal use issues that they run efficiently only during certain parts of the year, and perform poorly or even out of service for the rest of the time. To overcome the problems, this paper performs several tasks as follows. (1) A hybrid photovoltaic-water/air solar wall (HPSW) system is presented, which combines the air cooling channel and water cooling channel together in one single BIPVT system. (2) The HPSW system can run three modes according to different seasonal needs of the building: ① PV/Air mode in winter, ② PV/Water mode in summer, ③ PV-water/air mixing mode in transition season, which means that the new system is able to satisfy annual demands of the buildings. (3) The HPSW system were experimentally tested in different seasons under different modes during a whole year. (4) The results showed that the all-day average electrical efficiency can reach 15.3% by PV/Air mode in winter, 7.8% in summer and 11.6% in transition season by PV/Water mode. The average daily power generation of the system in summer, transition season and winter was 973.0 kJ, 3226.4 kJ and 4460.5 kJ, respectively. As for thermal performance, the PV/Water mode performed well both summer and transition seasons, with the average thermal efficiency of 55.1% and 51.5% respectively. The temperature rise of experimental room reached 8.1℃ compared to the reference room in winter. The results proves that the HPSW system can operate efficiently as expected throughout the year and has great value in different seasons and different regions.