Model selection for global and diffuse radiation over the Central Black Sea (CBS) region of Turkey

Solar radiation over the Central Black Sea Region of Turkey, covering the five provinces (Amasya, Çorum, Ordu, Samsun and Tokat), was analyzed to guide future projects. The maximum monthly average global solar radiation ranged from 20.05 (for Ordu) to 23.71 MJ m−2 (for Tokat). The maximum monthly average daily measured sunshine duration ranged from 6.89 (for Ordu) to 11 h (for Çorum). A quadratic polynomial equation was empirically developed to predict the monthly average daily global radiation. A hybrid model was also developed based on the predictions of six existing models to predict the monthly average daily diffuse and beam radiation. Various statistical tests (analysis of variance for model adequacy and t-test for significance of model parameter etc.) have shown that the models developed in this study are adequate for solar radiation prediction.