# Experimental Investigation of the BIPV System under Sanluurfa Meteorological Conditions
## 1 Introduction
### Literature Review  
The angle and facade direction of PV panels are important to obtain more electrical energy from the BIPV system. In this context, there are many studies. [PERSON] et al. [12] found that in a desert environment, between bifacial PV panels oriented at a 22\({}^{\circ}\) tilt facing south and those oriented 90\({}^{\circ}\) facing east, the ones facing south produced 14% more energy. [PERSON] et al. [13] concluded in their experiment with different facades across 78 cities that BIPV systems could be considered not only for roofs but also for facades in places located at lower latitudes. [PERSON] et al. [14] found that the PV panel can produce more electrical energy at a smaller tilt angle and that the annual production might decrease with an increase in the tilt angle. [PERSON] et al. [15] demonstrated that BIPV windows mounted on south-facing roofs in Egypt produced the maximum annual power, while north-facing BIPVs produced the minimum power. In an experiment conducted by [PERSON] et al. [16] in Hong Kong, a BIPV system was installed on the roof, south, west, and east facades of a building, and it was found that the best production was from the roof. In the BIPV study conducted by [PERSON] et al. [17], panels mounted vertically on the facades were compared with those mounted on the roof, and panels mounted at a 30\({}^{\circ}\) angle facing south on the roof were recommended for the highest performance. Many researchers have noted that, because of the low radiation on the north, west, and east-facing facades of BIPV systems, the electric energy economically produced is particularly low on the north and east-facing facades, taking into account the amount of radiation on these facades [18; 19; 20; 21; 22; 23; 24; 25; 26]. One of the most important parameters for increasing the efficiency obtained per unit area is the PV panel technology. In their study conducted in India, [PERSON] et al. [27] demonstrated that a-Si cells produced 14% less energy compared with p-Si cells during summer and 6% less during winter. In their experiment conducted in Spain, [PERSON] et al. [28] supportedthe findings of the study carried out in India. In a study conducted by [PERSON] et al. [29], when a BIPV system using a-Si technology was compared with a PV system composed of curved thin-film a-Si laminates, the annual energy gain of the second system was approximately 88% of the first system. [PERSON] et al. [21] demonstrated that in six Brazilian cities, the annual energy needs of a building can be met by using the building's roof and facade for BIPV application with thin-film Cadmium telluride (CdTe) materials. [PERSON] et al. [30] investigated three different transparency types (opaque, 30%, and 50%) of BIPV systems in Nice, Paris, and Lyon. In their BIPV experiment conducted in Italy, [PERSON] et al. [31] found that the CIGS and c-Si used in the photovoltaic module exhibited 45% and 20% less energy production, respectively, compared with a-Si. In the a-Si-based BIPV study conducted by [PERSON] et al. [32] in Zhuhai City, China, ventilated BIPV showed 0.2-0.4% higher performance compared with its nonventilated counterpart. They found that the highest production was obtained from the opaque PV panel type, and the lowest production was obtained from the PV panel type with the highest permeability. [PERSON] and [PERSON] [33] found, in a BIPV test facility consisting of two identical 10 m\({}^{2}\) rooms, that m-Si PV modules produced better results in energy production than CIS PV modules. One of the panel types that can be used in BIPV systems to obtain a higher amount of energy per unit area of the panel is the bifacial panel. In programs like Pvsyst, the analysis of ventilated systems of BIPV cannot be performed. [34]. In the ventilated bifacial BIPV system studied by [PERSON] et al. [34], a power gain of 2.9% compared with the ventilated BIPV system and 4.4% compared with the nonventilated BIPV configuration was achieved. In their study, [PERSON] et al.