Estimation of Solar Irradiance on Inclined Surfaces Facing South in Tanta, Egypt

The estimation of solar irradiance on inclined surfaces is very important to predict the performance of solar energy applications. In the present study the global solar irradiance on horizontal surfaces is measured for Tanta of latitude () during the period (2008-2009). Computer programs have been prepared to calculate the monthly average daily irradiance and hourly solar irradiance on inclined surfaces from horizontal global solar irradiance data. The hourly diffuse solar irradiance and the average monthly daily diffuse solar irradiance are estimated using Miguel et al. correlation and El-Sebaii and Trabea correlation for Egypt, respectively.