Eur. Phys. J. Plus (2017) 132: 216
https://doi.org/10.1140/epjp/i2017-11495-7

Regular Article

Estimating daily global solar radiation by day of the year in Algeria

Unité de Recherche en Energies Renouvelables en Milieu Saharien, URERMS, Centre de Développement des Energies Renouvelables, CDER, 01000, Adrar, Algeria

^* e-mail: nouar.aoun@gmail.com

Received: 24 January 2017
Accepted: 9 April 2017
Published online: 16 May 2017

Abstract

This study presents six empirical models based on the day-of-the-year number for estimating global solar radiation on a horizontal surface. For this case study, 21 years of experimental data sets for 21 cities over the whole Algerian territory are utilized to develop these models for each city and for all of Algeria. In this study, the territory of Algeria was divided into four different climatic zones, i.e., Arid, Semi-arid, Highlands and Mediterranean. The accuracy of the all-Algeria model was tested for each city and for each climate zone. To evaluate the accuracy of the models, the RMSE, rRMSE, MABE, MAPE, and R, which are the most commonly applied statistical parameters, were utilized. The results show that the six developed models provide excellent predictions for global solar radiation for each city and for all-Algeria. Furthermore, the model showing the greatest accuracy is the sine and cosine wave trigonometric model.