Determination of Angstrom-Prescott equation coefficients for some provinces in Eastern and Southeastern Anatolia using geographical and meteorological data

In this study, monthly average global solar radiation on a horizontal surface for eleven different locations selected in Eastern and Southeastern Anatolia Regions of Turkey (Gaziantep, Adıyaman, Kilis, Şanlı Urfa, Batman, Siirt, Tunceli, Mardin, Bingöl, Elazığ ve Diyarbakır) was estimated. For this purpose, ten different predictive models (M1-M10) used Angström-Prescott type equations depend on geographical and meteorological parameters were developed and empirical coefficients of the Angstrom-Prescott formulae were determined. By using some statistical indicators, i.e., R2, percentage error (e), RMSE, MBE and t-statistic, the obtained results from Angström-Prescott type equations were evaluated and compared the applicability and performance of the calibrated models with the measured values. Statistical indicators show that the total solar irradiance estimated from the models (M1-M10) is in good agreement with the measured values. Therefore, we suggest that the developed models can be calculated for estimation of solar radiation for every location in Eastern and Southeastern Anatolia.