Atmospheric extinction of solar radiation measurement in solar thermal electric plants

An optical system has been developed to measure the atmospheric extinction of solar radiation. The system applies optical imaging and image processing to obtain scientific information of interest. The system contributes to making solar concentration technology more efficient, helping to combat climate change. Future solar tower plants will have higher power and greater heliostats-central receiver distances, making important the atmospheric extinction of solar radiation effect. Until now, the extinction had been determined with unrealistic parametric models. Therefore, a procedure for measuring extinction based on an optical system has been developed. Simulations and calculations with radiative transfer codes were carried out to estimate the extinction levels expected. Based on these levels, the optical measurement system was developed. The system consists of two identical high-resolution digital cameras foccused at a Lambertian target at different distances taking simultaneous images. These images are converted into matrices with numerical values and after a series of complex operations the extinguished solar radiation is obtained. The daily extinction measured has been monitored for the first time in the control panel of a tower plant operating room with the rest of the meteorological control variables for the daily operation.