Abstract

The solar direct normal irradiance reflected by heliostats is partially extinguished on its way to the receivers in concentrating solar power tower plants. Atmospheric extinction or attenuation limits the amount of local useful solar resource available. Therefore, considering only direct normal solar irradiation in the solar resource assessment for solar power tower plant projects is inadequate and conducts to errors. In this paper, we present preliminary results of the evaluation of heliostat-to-tower atmospheric extinction values along the Sun Belt. In general, results show that the southern hemisphere has lower atmospheric extinction, where Chile stands out with values below 4% for an inclination range of 1 km, while West Africa in the northern hemisphere stands out stands out with values higher than 19%.