Empirical model for the estimation of global solar radiation for Indian locations

A new empirical model is developed to estimate the monthly average global solar radiation. The estimated values of solar radiation for eighteen Indian locations in different climatic zones of India are compared with measured values. The performance of the empirical model was evaluated on the basis of the statistical error tests: the mean percentage error, root mean square error and mean bias error. The values of mean percentage error, root mean square error and mean bias error are found to be in the range of -13.99 to 14.76, 0.00 to 15.26 and -4.73 to 6.73 respectively. Small variations in the errors have made this empirical model an easy asset to determine the solar radiation data with better accuracy and with less error at places where meteorological observatories are not established.