Statistical models for estimating hourly diffuse solar radiation in different regions of Thailand

In this study, four statistical models for estimating diffuse solar radiation from global solar radiation in different regions of Thailand have been developed. In developing the models, a 12-year period of global and diffuse solar radiation measured at four of our solar radiation monitoring stations, situated in different regions of Thailand have been analyzed. The statistical models estimate diffuse fraction from clearness index at the hourly scale. The performance of these models have been compared with that of other models. The models developed in this study performed best for most cases.