Medida y modelización de la componente difusa de la radiación solar total y ultravioleta

Resum

Accurate diffuse solar radiation measurements at the Earth’s surface are required to suitably the variations in the earth’s radiation balance and for the sustainable development of renewable energies, architecture, engineering, agriculture and ecology. This Doctoral Thesis contributes to a better estimation of total and ultraviolet diffuse irradiance, both regarding the correction of its measurements and the proposal of models for estimating it by using other magnitudes. Among the main sources of error affecting the process of measuring diffuse solar radiation, the thermal offset of the radiometer and the use of shadow rings used to block the direct component must be considered. In this work, experimental thermal offset values for different pyranometer models have been obtained while measuring global and diffuse irradiance, with and without mechanical ventilation, under a wide range of environmental conditions. Differences in the thermal offset between pyranometers have been analyzed and several models for correcting the error associated to the thermal offset have been proposed. This study also compares six mathematical models proposed to correct the error caused by the use of shadow rings for measuring total diffuse solar irradiance. Additionally, two original models are proposed to correct this error in ultraviolet diffuse irradiance measurements. Finally, three innovative models are proposed to estimate the diffuse ultraviolet irradiance in locations where experimental measurements are not available.