Solar extinction in thermoelectric solar tower plants: Model validation

One of the most significant factors that can affect the performance of thermoelectric solar tower plants is the solar extinction on the ground. Until now, rigorous validation of extinction models had not been possible due to the lack of sufficient experimental data. However, in this study a database with more than six years of measurements from Plataforma Solar de Almería (PSA) was used to rigorously validate them. In a previous work, a Typical Solar Extinction Year of the PSA was obtained with an average annual solar extinction of 6 ± 2 % for the measurement distance of 741.63 m. Daily simulated data for a period similar to the experimental extinction year were used to generate typical solar extinction years of the PSA. The inputs used were aerosol optical depth, precipitable water in an atmospheric column and the distance between the heliostat and the receiver. The best result was obtained using Polo et al model, with an average annual solar extinction value of 6 ± 2 % (741.63 m), in agreement with the characteristic experimental value at PSA. Therefore, this model was perfectly validated and could be used to estimate extinction worldwide to determine the best locations for future thermoelectric solar tower plants.