Global energy demand has increased alongside the improvement of technology, as has the importance of energy sources as the need for both conventional energy and alternative energy sources has increased. Conventional energy sources, which was the pillar of the Industrial Revolution, are facing a threat of both exhaustion and negative environmental impacts. According to TEİAŞ data, when the last two years were evaluated in terms of installed power according to Turkey's primary energy sources, it was observed that the rate of solar energy installed power had increased from 6 percent to 7.3 percent. Considering the Solar Energy Potential Atlas created by the General Directorate of Renewable Energy, it was seen that Turkey is a productive region in terms of sunshine duration. The photovoltaic panel system, which has an important role in Turkey, was designed and analysed via the Ansys program. In this study, the efficiency of solar cells made of different materials was analysed numerically with the Ansys program for electricity production in Istanbul. Considering the monthly average solar radiation data for the province of Istanbul between 2004 and 2018, their efficiency was compared using amorphous silicon (a-Si), cadmium telluride (CdTe) and gallium arsenide (GaAs) solar cells. In addition, the maximum and minimum temperature and total heat flux values for 3 different solar cells were shared separately. When the efficiencies of silicon (a-Si), cadmium telluride (CdTe) and gallium arsenide (GaAs) solar cells were compared, it was observed that Si solar cell values had the lowest values in the summer months, while GaAs solar cell values had the lowest values in the winter months.