Novel short term solar irradiance forecasting models

The Angstrom-Prescott (A-P) type models are widely used for solar irradiance forecasting. These models use the sunshine duration and extraterrestrial irradiance values. The accuracies of the A-P models are highly region dependent coefficients. Therefore, these coefficients are determined empirically. In this study, five novel semi-empiric models for hourly solar radiation forecasting are developed. These models utilize historical data of the solar irradiance, the extraterrestrial irradiance and the clearness index while forecasting. To test the effectiveness of the proposed models, three different regions are deliberately selected, and solar data are measured and collected hourly. To show the effectiveness of the proposed models, the forecasting results are compared with the A-P type equation based models. The proposed approach is concluded to be superior compared with the previously developed A-P type equation based models.