Impact of cloudiness on direct and diffuse components of horizontal solar irradiation

摘要

One of the main tasks when planning a solar power plant is making a good resource analysis of the location of interest. In this paper, solar radiation data are aggregated by pyranometer which is used for measuring ten-minute values of solar irradiance on a horizontal surface during a whole year. Solar irradiance on a horizontal surface can be decomposed to direct and diffuse components. It is clear that cloudiness has a great impact on both direct and diffuse components of solar radiation. Based on one year solar irradiance measurement data, the sensitivity of direct and diffuse components to cloudiness has been analyzed. Cloudiness data used in the analysis are obtained from the standard hydro-meteorological measurements carried out by meteorological station. Based on the dependence of relative values of direct and diffuse horizontal irradiation on cloudiness and by using the calculated reference values of horizontal irradiation, a simple model for estimation of solar insolation is derived.