Long time series solar spectra used for solar field performance evaluation

Abstract

Concentrated Solar Power (CSP) uses large solar fields composed of mirrors coupled with linear or punctual thermal absorbers and glasses, for ensuring insulation or protection. Each component previously cited must reflect, absorb or transmit a large part of the sun’s radiative energy. For calculating their respective efficiency, the different organizations for standardization and measurement currently use the ASTM G173-03 [1] standardized solar spectrum. This standard spectrum has been proposed in the early 2000s, using an average of the clear-sky conditions above all the USA for photovoltaic applications. The aim of the present contribution is to compare the real solar efficiency of each optical component to the efficiency calculated with the ASTM standard, by using a long time series of located solar spectra, function of the local atmospheric conditions. For this study, we have selected 10 sites around the world on the AERONET database before using the software SMARTS 2.9.5 for modeling one Direct and Circumsolar (DC) solar spectrum per available data. We obtained thousands of solar spectra per sitewhich allow us to calculate solar annual performances and to compare them with the current solar standard ASTM G173-03 solar spectrum.