Distribution of diffuse and direct insolation over Pakistan

Abstract

With the exception of a three year record of diffuse insolation over Quetta, diffuse and direct insolation is not recorded at any location in Pakistan. The empirical relation due to Mani and Chacko (Solar Energy14, 139, 1973) for diffuse insolation has therefore been applied to estimate diffuse insolation over 37 locations in Pakistan and three neighbouring stations. Direct insolation is also obtained for the same locations. Using the data for 40 locations, diffuse and direct insolation is presented on maps. The isolines are compared with the results obtained for India and world maps.