Approach to drawing new global solar irradiation contour maps for Argentina

Abstract

Given the shortage of solar irradiation measured data accurate enough to fulfill statistical conditions to be considered representative in time and space, there appeared alternatives for estimating them on the basis of the existing meteorological information, and one of the values used was the number of hours of bright sunshine. In this paper a limited number of stations is considered where the daily hours of bright sunshine and of global irradiation were measured simultaneously, thus making it possible to find the constants of the Ångström–Prescott equation for each month. The spatial distribution curves of those constants for the whole country were drawn using the kriging method. From them, and taking into account the data from bright sunshine hours measured in a great number of stations, charts with the distribution of hours relative to bright sunshine were drawn using the above-mentioned interpolation method and the Ångström–Prescott linear equation was applied; mean values for the whole territory were thus found. Using once again the geostatistical interpolation the charts with the space–time distribution of the resource were drawn; the error evaluated is in the order of 10%. The results obtained for the months of January and July are shown for illustration purposes.