Comparative study of models solar radiation in Sub-Saharan environment

The depletion of fossil and natural energy resources such as oil, gas and uranium is decreasing due to the current high consumption and the development of the industry in recent years. Climate change and pollution require a reflection on the energy need by a rapid transition to renewable energies. To cover energy needs, research is being conducted on renewable energy. One of the renewable energies which can fulfill the demand of the world until now, is solar energy, It is the direct source of generation of heat, light, and electricity and which is free and inexhaustible in most of regions of the world, this energy can be used in different ways, either in photovoltaic systems for the production of electricity, or in thermal systems for the production of hot water in the housing sector. In this article we will do a comparative study. One consists in determining the two empirical models (Davies & Hay and Ashrae) which will allow us to estimate the daily irradiations on a horizontal plane, and on the other hand we compare it by the results measured in the site of Adrar at the time of four seasons. A comparative study of the results obtained by simulation of the two models showed that the Ashrae model gives a better estimate of the global solar components, the absolute mean error does not exceed 6% and the correlation coefficient was greater than 0.97, as did the relative coefficient of the bias error does not exceed 5% in absolute value, relative RMSE does not exceed 9%.