Temperature based model for estimating the daily average global solar irradiation of Ibadan, Nigeria

This paper presents the temperature based models for predicting the daily average global solar radiation of Ibadan. The data used in developing the models consist of daily average global solar radiation, minimum and maximum daily average temperature collected over a period of 9 years at International Institute of Tropical Agriculture (IITA) located in Ibadan. Different variations of temperature model are derived and compared. The suitability of the models is ascertained using standard statistical tests: Mean Bias Error (MBE), Root Mean Square Error (RMSE), Mean Percentage Error (MPE), and Correlation Coefficient (R). One of the key results shows that a quadratic temperature model present the overall best model for predicting the global solar radiation of Ibadan with MBE of 1.86 MJm^-2day^-1, RMSE of 2.7, MAPE of 9.34% and R of 0.68.