Estimation of the global solar radiation in Greece

Abstract In this paper a method to estimate the global solar radiation in Greece is proposed. Measurements of the global solar radiation available by seven meteorological stations in Greece are used to obtain the regional regression coefficients of the Page formula. Using polynomial regression techniques, analytical expressions of these regression coefficients are obtained as a function of the mean monthly relative sunshine duration. Estimations of the monthly global radiation are performed for 31 locations in Greece. The values of solar radiation predicted by this method are in close agreement with the measured ones. Comparison with predicted values, from previously published works on solar radiation in Greece, shows that the present method indicates a higher degree of accuracy.