In this Book, we are interested in studying of different solar radiations in each region of Arabic area. Also, we are interested to create an interface with Matlab Guide that is named Solar Radiations. This numerical interface includes five sections that the first section is the background of the interface. The three other sections are the studies sections on the solar radiations that are the monthly horizontal solar radiations, the hourly, daily and monthly solar radiations and the diffuse solar radiation models. In addition, the latest section is the application section on the photovoltaic technology. Moreover, the interface provides the studies of different solar radiations and also allows others techniques to estimate the variation of diffuse radiation using the isotropic and anisotropic methods and to evaluate the photovoltaic electrical source surfaces in each region of Arabic area. All of these studies provided by our interface take account the variation of the tilt angle β, the latitude φ, the longitude L, the albedo ρ and the Azimuth of slope.