Comparison of three methods for estimating the global solar radiation of Faya-Largeau in the Saharan zone, Chad

Abstract

In this work, we make a confrontation between measured values of the solar radiation given by NASA and those estimated by the mathematical models suggested in the literature. The chosen mathematical models are those of the model of Angstrom, Allen and the model of Sabbagh which are described as the best models. The three methods used the root mean square error (RMSE),mean bias error(MBE), mean percentage error(MPE) and nash- sutcliffe equation(NSE) was compared with failure analysis. The site of Faya-Largeau has been chosen as reference. The comparative study of the obtained results showed that the model of Sabbagh presents a best estimation of the global solar radiation with a value of 6.013 kWh/m2/day in particular for an incidence on horizontal level. Well cavity, it arises that the site of Faya-Largeau being in the Saharan zone of Chad has a good solar potential for the exploitation of photovoltaic solar energy.