Tamanho da fonte: 

Due to the atmospheric conditions in which the sky appears, that can reduce substantially the solar energy until it reaches the earth surface, bringing inefficiency success of postponing this resource. This research aim in create a theoretical demonstration of clear sky index to classify the days of the year. Here was followed an demonstrative sequence, that consists in established the days accumulated and them demonstrate empirically the expression for calculate the total radiation, the sum of theoretical total solar radiation and the diffuse, at the end was determined the qualitative values of clear sky index. So the results show that the clear sky mean the relation between the global horizontal irradiation and the total radiation, and it vary from 0 and don’t exceed 1.4 and the days can be classify as cloudy, clear, else the intermediate sky days. Results agree with those reported for example in Lohmann et. al., (2016), being distinguished by the fact that it addresses the calculation of the density of Kernel Density, however there is agreement in the two methods. And was concluded that for the removal this variability type is introduce the lightness index, but better perform the clear sky index.
Keyword: Clear sky index, clearness sky index, solar radiation,Kernel density.