Estimating Global, Diffuse Solar Radiation for Chhor and Validation with Satellite-Based Data

Abstract

The study of solar irradiation has been carried out for the first time over Chhor (city of Sindh province in Pakistan). In the present work, measured data of bright sunshine hour of the regions have been used to estimate monthly average daily global and diffuse solar radiation. Regression coefficients a and b have been calculated from the first-order Angstrom type correlation for the city using relationship given by Tiware and Sangeeta. The results obtained through four empirical models i.e., Angstrom, Liu and Jordon, Page, Hawas and Muneer were compared with values obtained from NASA Satellite-based Global and Diffuse radiation data. A good agreement was found between satellite-based values with Muneer and Hawaas model. The global irradiation is found high from April to July for the period of study. The statistical error tests—mean bias error, root mean square errors are used to validate the estimates using satellite-based data. MBE has lowest values for diffuse solar radiation than global radiation and shows over estimation. The value of coefficient of determination implies that 98.7 % of NASA can be accounted by estimation of global solar radiation Chhor. Low values of variance suggest that the correlation is best fitted.