CONTRIBUTION TO THE STUDY OF TWO METHODS FOR ESTIMATING DIRECT AND DIFFUSE SOLAR RADIATION IN MOROCCO AT THE FÈS-SAÏS SITE

In this work, we have developed a comparison between solar radiation values measured in Morocco and values estimated by two theoretical models proposed in the literature by various researchers. The selected site is the synoptic station of the city of Fez in Morocco, in which meteorological and radiometric data are continuously collected. For the two chosen theoretical models, the first model is the Barbaro et al (1977) and Davies el al (1975) model for direct and diffuse rays respectively, based on the kasten (1980) model for the determination of the Linke turbidity values as an atmospheric turbidity parameter. The second model differs from the first by using the Ineichen and Perez (2002) model using atmospheric transmittance for the determination of the atmosphere turbidity, the transmittance values will be calculated using the Schillings et al. (2004) model. Comparing the two models applied to the case of Morocco resulted in the decision that the model of Ineichen and Perez (2002) is best suited to the climatic conditions in Morocco with the lowest normalized square error of 7%, taking into account the locals climatic conditions of the site investigated.