Global Solar Radiation Estimation Using Sunshine Duration in Nigde

In this paper, several equations were employed to estimate global solar radiation from sunshine hours for a meteorological station in Nigde, Turkey, using only the relative duration of sunshine. These equations included the original Angstrom-Prescott linear regression and modified functions (quadratic, logarithmic and exponential functions). Estimated values were compared with measured values in terms of the coefficient of determination, root mean square error and mean absolute percentage error. All the models fitted the data adequately and can be used to estimate global solar radiation from sunshine hours. This study finds that the linear models performed better than the other models and it is preferred due to its greater simplicity and wider application.