Calibration of six thermal amplitude models for estimating the daily global solar radiation as a source of clean energy by Penman-Monteith model over Saudi Arabia

This research presents an analysis of the estimated solar radiation using Maximum and minimum daily temperatures (Tdmax and Tdmin), and by applying six models (Hargreaves-Samani, 1982; Allen, 1997; Bristow-Campbell, 1998; Samani, 2000; Annandale, 2002 and Che, 2004). The estimated solar radiation was calibrated by the data sets derived from Penman_Monteith model. The model performance was analyzed using four statistical models (RMSE, ME, R2, MAE). the clear radiation proposed by Penman-Monteith model. The different statistical indicators show that the Chen estimations perform the best among the studied empirical models in Abha, Riyadh, Al Wajh, Buraydah and Najran. The Annandale estimations were the best in Tabouk and Ar’ar. The best daily estimations of solar radiation were obtained by Samani model in Turayf and Qaysumah.- Objectives of the study This study seeks to analyze the variability and determine the best model of estimating the daily solar radiation using the temperature data 1985-2018 recorded in nine weather stations.