Development of New Empirical Correlations for Diffuse Solar Irradiance in Shiraz, Iran

As solar radiation hits the atmosphere, it is divided into two parts: beam (direct) and diffuse components. Information about the quality and quantity of these two components on the surface of the earth is of great significance for different applications in science and engineering. To measure the diffuse component, one method is to protect the pyranometer form the beam component using a shadow band. In the present study,diffuse component of the available solar radiation in Shiraz, Iran is measured instantaneously, using a shadow band. Also, a novel analytical method is applied to calculate the shadow band correction factor based on the concept of radiation shape factor. Finally, two new instantaneous and hourly correlations are proposed to estimate diffuse solar radiation as a function of respective clearness index

Keywords:

Diffuse Solar Radiation , Shadow Band , Correction Factor , Instantaneous Model