Spectral effects and determining the solar spectral distribution for Mugla and Ankara

Not only the theoretical calculation of the amount of solar radiation but also the characteristics of the light is very important in determining the efficiency of the PV module. There are no theoretical and experimental studies on this subject in Turkey until now. The amount of incoming radiation varies depending on the wavelength. The amount of radiation and the quality of the light in the atmosphere varies due to many atmospheric effects. The variation of the amount of incident radiation depending on the wavelength for different air mass values. Photovoltaic systems convert solar energy into electricity. The main part in this system is photovoltaic module which directly convert solar energy into electricity. So the material and the kind of photovoltaic modules are very important because they effect the cost directly. Besides this their electronic properties determine the amount of radiation coming to the surface. The amount of incoming radiation is reduced and the wavelength is changed by atmospheric factors. The determination of these effects is very important in calculating the amount of radiation and also for the electricity output. SPCTRL 2 calculates the amount of radiation coming from a number of atmospheric effects. In the program, the wavelength-dependent variation of the amount of radiation can be calculated considering the atmospheric effects for a desired region. In this study, the amounts of radiation coming to the surface having horizontal and different tilt angles were calculated for Mugla and Ankara. It has been found that the amounts of incoming radiation vary due to regional reasons.