Energy yields of photovoltaic power plants are directly related to the availability of the global solar radiation (GHI). An accurate performance analysis of these power plants depends strongly on the quality and the reliability of the solar resource assessment. This study proposed to improve the accuracy of the GHI database provided by satellites. Two quality improvement methods have been proposed and evaluated in this study. The first developed method consists in combining a GHI satellite‐derived database with the best ground station models, while the second one consists in performing a linear correction of a satellite database. The purpose of this study is to investigate the quality improvement method that gives more accurate GHI prediction. The comparison between the two developed methods shows that the resulting combination method database achieves higher GHI prediction accuracy than the linearly corrected satellite database. This combination reduces the uncertainty of the original satellite database by 1.95%, with a resulting relative root‐mean‐square error (rmse%) reaching 4.74%.