Atmospheric extinction levels of solar radiation using aerosol optical thickness satellite data. Validation methodology with measurement system

Abstract

In order to make the concentrating solar power (CSP) more competitive, an accurate prediction of the solar radiation incident on CSP tower plant receivers is necessary. The extinction in the heliostat-receiver pathway plays an important role in the optical loss of the solar field and therefore, in the performance of the plant. In order to correctly operate these kind of plants and to select new potential emplacements, it is necessary to know the on-site levels of extinction. A methodology was developed in another published work, called Extinction AOT method (EAM), with the purpose of finding out the levels of extinction present at a location using AERONET AOT as input data. However, there is no AERONET AOT data available at any potential site of interest for setting up a solar tower plant, so, alternative approaches were necessary. This paper proposes to determine levels of extinction at any location using AOT satellite data instead of AERONET data. These results have been compared with results obtained applying the EAM with AERONET data and using real extinction measurements obtained with the CIEMAT extinction measurement system. The extinction obtained at PSA has been 5% in all cases considering the error rates.