Their experimental results show that 53% of the solar energy incident on the PV-T collector was transmitted through the PV cells, 18% was dissipated as waste heat in the PV cells, 4% was converted to electricity by the PV cells, and 23% was lost to reflection.
Solar PV-T collectors Most of the solar radiation absorbed by a PV cell is converted to heat (in fact, internal energy), increasing the temperature of the cell and decreasing its electrical efficiency [35, , , ].
Table 9. Summary of research on solar PV-T polygeneration systems. 16-15%. In Hong Kong, Shanghai, and London, respectively. For PV-T + WSHP and PV-T + W&ASHP systems, respectively. Yearly averaged COP.
Water-based collectors are considered the most efficient type of PV-T technology for applications where water preheating is required all year long at locations with high solar input and high ambient temperature (low latitudes) [35, 48, 73, 118].
In this line, the thermal outputs of water-based PV-T and CPV-T collectors have been integrated with solar thermal-driven cooling units, such as absorption, adsorption or desiccant, for cooling provision [64, 542]. Fig. 46. Breakdown of solar-powered cooling systems.
When PV cells are installed either on the facades or roofs of a building creating the external structure or skin of the building, they are referred to as building-integrated photovoltaic (BIPV) collectors. BIPV systems are used mainly to produce electricity, but also provide hot air for space heating, which is an added benefit.