To integrate Solar Thermal Electric (STE) Plants energy production into the electric power supply system of a country, it's necessary to solve some uncertainties about availability of solar resource. One of these is the accurate knowledge of solar radiation reaching solar receiver. Solar radiation is attenuated by aerosols and molecules present in the Atmosphere. Estimation of this phenomenon is complicated due to environmental factors on which it depends. Currently there are some methodologies in literature to estimate it (parametric models, simulations tools, radiative transfer codes (RTC) or visibility instrumentation). A new approach to estimate the extinction in STE Plants has been elaborated. Developed model uses atmospheric realistic conditions present in a real location. With this purpose, a Typical Aerosols Year (TAY) has been elaborated using NREL Methodology for Typical Meteorological Years. TAY has been created processing aerosol data provided by an AERONET station located at PSA. Using TAY has been obtained the typical spectral transmittances levels at PSA, with RTC. Attenuation model results from transmittances levels, has been used to acquire production and economic losses due to extinction in a simulated STE Commercial Plant at PSA. Results have been compared with others in the literature for the same emplacement. (C) 2017 Elsevier Ltd. All rights reserved.