# Experimental Investigation of the BIPV System under Sanluurfa Meteorological Conditions
## 3 Results and Discussion
Plane**} & \multicolumn{1}{c}{**and Shadings**} & \multicolumn{1}{c}{**the Array**} & \multicolumn{1}{c}{**Grid**} \\  & \multicolumn{1}{c}{**(kWh/m2)**} & \multicolumn{1}{c}{**(kWh/m2)**} & \multicolumn{1}{c}{**(kWh/m2)**} & \multicolumn{1}{c}{**(kWh/m2)**} & \multicolumn{1}{c}{**(kWh/m2)**} & \multicolumn{1}{c}{**(kWh/m2)**} & \multicolumn{1}{c}{**(kWh)**} & \multicolumn{1}{c}{**(kWh)**} \\ \hline \multirow{3}{*}{January} & Bifacial & 77.5 & 28.30 & 128.4 & 122.9 & 41.29 & 39.78 \\  & Monofacial & 77.5 & 28.30 & 128.4 & 121.9 & 39.57 & 38.16 \\  & Eastern  
annual total electrical energy production of 379.41 kWh, compared with the panel on the eastern facade, which produced 313.35 kWh of energy. Similar to the study conducted by [PERSON] et al. (2018) [12] under the conditions of Sanluurfa, it was observed that the southern facade has a higher energy potential compared with the eastern facade. According to the PVsyst analysis, the highest annual total amount of electrical energy--505.64 kWh--was produced on the roof. The highest production being observed on the roof supports the findings of studies conducted by [14; 16; 17; 38]. Under the conditions of Sanluurfa, the most suitable facade for the BIPV system was determined to be the roof with tilt and azimuth angles set at 0 degrees. In the PVsyst analysis, the bifacial panel on the south facade produced a total of 401.65 kWh of electrical energy in one year, while the monofacial panel produced 379.41 kWh. In the PVsyst software, the bifacial panel produced 5.86% more electrical energy in one year compared with the monofacial panel. In the experimental setup, over a span of 6 months, the total energy produced by the bifacial panel was 176.57 kWh, while the energy produced by the monofacial panel was 153.45 kWh. In the experimental setup, considering the total energy produced over 6 months, the bifacial panel produced 15.1% more than the monofacial panel. In both cases, the bifacial panel was more efficient compared with the monofacial panel under the same conditions, as found in the study conducted by [PERSON] et al. (2021) [34]. The production of the bifacial panel in the experimental setup, which was 15.1% higher than that of the monofacial panel, was higher than the 5.86% ratio in the PVsyst analysis. The difference in the experimental setup was found to be 9.24% higher compared with the difference in the PVsyst analysis. The reason for this is the placement of a reflective surface with reflecting properties on the back wall of the bifacial panel in the experimental setup. Because of the reflective surface, the solar radiation that seeps behind the panel strikes the reflective surface instead of the wall, elevating the production level of the rear surface of the bifacial panel to higher values. Contrary to the experiment conducted by [PERSON] et al. (2021) [36], the efficiency of the bifacial panel was enhanced by providing a uniform reflection to the panel's rear side through the reflective surface. When looking at Table 2, the energy amounts produced by all monofacial panels in the experimental setup were found to be higher or lower (error rates) compared with their productions in the PVsyst analysis. However, in Table 2, the amount of energy produced by the bifacial panel in the experimental setup was consistently higher than the production results of the bifacial panel in the PVsyst analysis for every month of the 6-month period, with the exception of March. Thus, it was proven that the aluminum foil used in the experimental setup is an effective reflecting agent, and it enhances the efficiency of the bifacial panel. As can be seen from the results of the PVsyst analysis (Table 3), the highest annual production was found on the roof, amounting to 505.64 kWh. In addition, in the experimental setup (Table 2), the highest production over 6 months was also observed on the roof. In the experimental setup, it can be anticipated that using the bifacial panel in conjunction with the reflective surface on the roof might produce a greater amount of electrical energy.