Estimation of global solar radiation in Venezuela

A new relationship between sunshine duration and solar radiation was investigated through the analysis of data on monthly global solar radiation and hours of bright sunshine for eleven meteorological stations in Venezuela during the period 1964-1993. Linear regression was used to fit the Angstrom-Prescott equation. Estimated values were compared with measured values in terms of root mean square error mean bias error mean absolute bias error, mean percentage error, and mean absolute percentage error It is recommended that the t-statistic be used in conjunction with a set of error statistical parameters to more reliably assess a model's performance. All the models fitted the data adequately and can be used to estimate monthly mean solar global radiation from sunshine hours. The Angstrom-Prescott's correlation obtained for the eleven cities can be used for estimating global solar radiation in Venezuela where only sunshine hours data were available.