Estimation and validation of a clear sky hourly global solar radiation in Beni-Suef, Egypt

Abstract

The availability of hourly and daily solar radiation data is considered one of the important design tools for several solar energy applications. The objective of this work is to develop a model to calculate the hourly solar radiation falling on a horizontal surface in Beni-Suef city, Egypt via a validated simulation model. This model will help the researches in upper Egypt universities along with the designing of solar energy projects in the Beni-Suef city residential and industrial zones. The average solar radiation is calculated daily on hourly basis throughout the year, then the monthly average solar radiation is estimated. The results indicate the maximum value of average solar radiation is in June as 8.1 kWh/m2/day. Solar radiation is also calculated with several tilt angles to find out the optimum tilt angle that enable the surface to receive maximum solar radiation. The calculations focused on empirical equations of solar radiation and the experimental measurements obtained from the nearest station to the location. The model describes solar equations and it can be used to estimate global irradiance. Also, it shows the parameters of the system and climate change of the specific site (Beni-Suef city). Results are validated by comparison between the measured, calculated, and published reference data for the specific site and obtained good agreement with each other. It is found also that the optimal tilt angle that receives maximum solar radiation is 29 deg. which comply with the latitude angle of Beni-Suef city.