In solar energy projects, factors such as radiation, wind direction, sunshine duration, land type, panel orientation, as well as correct product selection, correct installation and workmanship are of great importance. All of these factors can have a direct impact on the efficiency of solar energy systems. Therefore, each factor must be examined in detail and the best solutions must be selected in accordance with the requirements of the project. If the right decision is not made, operating costs may increase and system efficiency may decrease. Therefore, it is very important to understand the basic factors and their effects in solar energy projects and to apply them correctly.