Estimation of solar irradiance on tilted surfaces facing south for Tanta, Egypt

Abstract

This paper aims to investigate a computer program using Pascal language to estimate solar irradiance on inclined surfaces. The global solar irradiance on horizontal surfaces is measured for Tanta at 30°47′ latitude and 30°99′ longitude for the period 2008–2009. The computer program has been prepared to calculate the monthly average daily irradiance and hourly solar irradiance on inclined surfaces using the measured horizontal global solar irradiance data. Hourly diffuse solar irradiance and the monthly average daily diffuse solar irradiance are estimated using Miguel et al. and El-Sebaii et al.’s correlations for Tanta, Egypt, using a computer program. The presented method is used to estimate hourly, global, diffuse solar radiation for horizontal surfaces and total solar radiation on both inclined and vertical surfaces at different orientations with a greater accuracy for any location.