Experimental analysis of parameters affecting the design of building integrated photovoltaic applications

The importance of taking measures against global warming through buildings becomes evident when considering that nearly 40% of the total CO2 emissions released into the atmosphere today are attributed to the energy consumption of buildings. Therefore, the concept of Nearly Zero Energy Buildings (NZEB) comes to the forefront. Buildings use Building-Integrated Photovoltaic Thermal (BIPV/T) systems to generate their own energy. However, buildings face limitations in terms of the facade and roof areas required for BIPV/T systems. Therefore, experiments were conducted in the study to enhance the efficiency of BIPV/T systems under the meteorological conditions of Şanlıurfa, Turkey. In this thesis, as an innovative aspect of the study, bifacial (double-sided) and monofacial (single-sided) panels with the same production potential were installed on the south facade and tested during the winter and summer seasons with varying air flow velocities and different air gap distances. In addition, considering the application of the BIPV/T system in buildings where the indoor environment is air-conditioned during the summer, the same configurations were implemented with the indoor environment being cooled. Another innovation introduced by the study is the placement of a reflective surface on the wall behind the bifacial panel, aiming to enhance the electrical energy efficiency of the bifacial panel. This situation was substantiated through PVsyst analysis. Furthermore, through the comparison of the year-round performance of monofacial panels with the same potential installed as a BIPV system on the roof and east facades, it was determined that the best annual electricity production in Şanlıurfa conditions occurs on the roof. Both panels on the south facade have provided maximum thermal energy efficiency at high air flow rates and the shortest air gap distance. Additionally, it was observed that using BIPV/T systems in Şanlıurfa during summer conditions allows raising the indoor temperature to 50 °C, making it suitable for cabinet-type dryers for food drying. In winter conditions, it has been found that the BIPV/T system can provide significant support to the building's thermal load for space heating and elevate the indoor temperature by 12 °C to 15 °C compared to the outside temperature. The results of the panel and indoor temperature were validated through Comsol CFD (Computational Fluid Dynamics) analysis. It was found that as the air gap distance between the bifacial panel and the wall increases, the electrical energy efficiency increases. In experiments conducted during winter, the bifacial panel exhibited superiority over the monofacial panel in all configurations, with an electrical power generation surplus ranging from at least 8.33% to a maximum of 12.73%. In the summer experiments, it was found that the bifacial panel produced an electrical power surplus compared to the monofacial panel, ranging up to 18.19% under the same conditions. The cooling of panels through air conditioning of the indoor environment during summer resulted in a higher electrical power generation by reducing the panels temperature. In addition, it was observed that the glass-glass constructed bifacial panel is more resilient to temperature in terms of electrical efficiency. In both seasons, it was found that the panels exhibit their best electrical performance when subjected to the fastest air flow and the farthest air gap distance between the wall and the panel. In a BIPV/T system utilizing bifacial panels, using the shortest air gap distance during the heating season and the longest air gap distance during other seasons can provide the highest energy efficiency for the building throughout the year.