The South American High Plateau (Altiplano) is one of the few regions on the planet believed to receive, at certain sites, an annual mean daily direct solar irradiation greater than 9 kWh/m(2) (32.4 MJ/m(2)). The veracity of this estimation is important because it implies that establishing large solar power stations in the region would be highly profitable. However, the measured data are highly localised, and the knowledge of the spatial distribution of the resource could be insufficient. To address this problem, the global and direct normal solar radiation data measured at eight stations distributed in northern Chile were compared with the SWERA database for South America. The differences found between the estimated and measured values were as high as 11%, on an annual basis. Thus, the SWERA database could be used to construct maps of the isolines of direct solar radiation to help visualise the spatial distribution of the resource. An analysis was performed to determine the per cent variation of a solar field collection area designed to achieve stable energy production throughout the year. Based on the analysis results, the northern region of Chile presents an economic potential much greater than that of the Mojave Desert from the point of view of the economic risk for a solar venture. This information can serve as a useful and reliable tool because it represents the initial assessments of optimal sites for installing solar power stations. (C) 2014 Elsevier Ltd. All rights reserved.