Building-integrated photovoltaics in hot climates: Experimental study of CIGS and c-Si modules in BIPV ventilated facades

Abstract

Buildings, especially mid- and high-rise ones, offer the opportunity to incorporate Photovoltaics (PV) on their vertical surfaces in addition to their roofs. This is achieved through Building Integrated Photovoltaic (BIPV) solutions. Ventilated facades in buildings can facilitate PV integration and improve the envelope's thermal performance. However, research on BIPV ventilated façades is lacking in the Gulf and MENA regions. Considering the area's harsh climate, investigating these facades is critical. Therefore, the authors of this paper conducted comparative experimental research on the energy performance of BIPV ventilated facades in the hot climate of Dubai. For a year, they monitored the energy yield and temperatures of Copper Indium Gallium Selenide (CIGS) and monocrystalline silicon (c-Si) modules on the south, east, and west facades. In addition, the study analyzed the effect of the modules' characteristics, orientation, temperature, and solar angle on the energy yield. Despite the hot temperatures, the monthly area-normalized energy yields of the c-Si modules were consistently higher than the CIGS modules across all orientations, with an average difference of 13.6%. The modules in the south facade produced the highest annual yield. Also, from October to February (the coolest period), the energy yield of the south modules surpassed the east and west modules by 41.6% and 48.5%, respectively. However, from April to August (the highest energy demand period), the east and west energy yield exceeded the south by 40.9% and 32.5%, respectively. In addition, the west-facing modules experienced higher temperatures than those in the east, resulting in an average of 12% lower energy yields. Hence, the east façade has performed the second best. The west façade production, nevertheless, closely coincides with Dubai's peak periods curve. Thus, the combination of modules on the west and south facades achieved the strongest generation-consumption correlation.