New sunshine-based models for predicting global solar radiation using PSO (particle swarm optimization) technique

► The first study to apply an intelligent optimization technique to more accurately determine empirical coefficients in solar radiation models. ► New models which are presented in this study have better performance than existing models. ► The empirical coefficients found for a given latitude can be generalized to estimate solar radiation in cities at similar latitude. ► A fair comparison between the performance of PSO and SRTs on GSR modeling.