Spectral Circumsolar Radiation Contribution To CPV

The prediction of the circumsolar augmentation of the direct normal irradiance incident on a CPV collector is difficult because it depends on many factors, such as solar position (air mass), atmospheric conditions, wavelength, and collector's opening angle. A general assessment of the circumsolar effect is described in this study, based on recently introduced instrumentation to measure the aureole's radiance, and appropriate radiative transfer modeling. Results of parametric simulations obtained with the SMARTS radiative code using variable air mass, aerosol conditions, and concentrator geometries are presented.