The insensitivity to energy quality is one of the disadvantages of an energy analysis when compared to an exergy analysis. It is only the exergy analysis that clearly reveals the degradation of energy quality in the processes of absorption and emission of solar radiation. The national spatial distribution of mean monthly exergy values of solar radiation over Turkey was mapped at 500-m resolution using universal kriging based on solar radiation data from 152 geo-referenced locations. Mean exergy value of solar radiation in Turkey was estimated at 13.5 +/- 1.74MJm(-2)day(-1), with a mean annual exergy-to-energy ratio of 0.93. (C) 2010 Elsevier Ltd. All rights reserved.