Empirical models for estimating the global solar radiation of Jubail Industrial City, the Kingdom of Saudi Arabia

Empirical models provide precise and cost-effective information on solar energy assessment. The main objective of this work is to create and examine some regression models (linear, quadratic and logarithmic), for the estimation of the monthly global solar radiation potential in the Jubail Industrial City of Saudi Arabia. The industrial city has more solar energy potential, and the global horizontal irradiance is ranging from 4000 to 7000 Wh/m(2)/day. In order to initiate the green energy development in the city, site-specific hybrid models, which includes the ambient temperature, sunshine hours and relative humidity have been developed. Precise equation for the three proposed models is built up and examined for the industrial city. All the three empirical models provide good results. The statistical error estimation of the developed models reveals that the estimated and measured values appear exceptionally great and deliver similar outcomes. The values of the correlation coefficient and coefficient of determination of the quadratic model are 0.939 and 0.925, respectively, which are the highest among the three models. The mean absolute percentage error of the quadratic model is only 6.17%, and the other statistical errors are also comparatively low for the quadratic model. Therefore, the quadratic model gives an improved approximation on the estimation of solar energy parameters in which the errors between the measured and calculated values are smaller. Thus, the present regression models provide valuable data on the solar strength probable in the industrial city, and the data could be used for future energy planning.