In this work meteorological data was used to estimate the global solar radiation in Bauchi, Bauchi state, Nigeria. The study examines the impact of cloud cover, relative humidity and the daily values of global solar radiation in Bauchi, Nigeria, using different proposed empirical models for a period of 10 years (1985-1994). The Angstrom model was used as the base, while other regression equations were developed by modifying Angstrom equation. The accuracy of the developed model was tested using statistical indicator that is, Response Surface Methodology (RSM). The equation with high value of correlation coefficient is considered as the best equation and is given as, It was observed that the new model can be used for estimating daily values of global solar radiation with a higher accuracy and has good adaptability to highly variable weather condition. The equation could be employed in estimating global solar radiation of location that has the same geographical location information as Bauchi.

Keywords: Relative humidity, Global solar radiation, correlation coefficient, coefficient of determination, Cloud cover.