Comparative analysis of different empirical relations for the computation of the regression coefficients and the global solar radiation for the climatic conditions of Vhembe District in Limpopo province of South Africa

摘要

An attempt has been made to study the suitability of the different empirical formulae to determine the regression coefficients for the climatic conditions of Vhembe District in Limpopo province of South Africa. Most of these empirical relations available in the literatures use the weather station data such as sunshine hours, precipitation, air temperature, etc. Theoretical estimation of the global solar radiation needs the basic understanding of the regression coefficients (a and b). The weather station data from the Agricultural Research council (ARC) and South African Weather Services (SAWS) are used in the present study to evaluate the regression coefficients for one station. The computed values of this station have been used to evaluate the global solar radiation for other stations in this region and compared with the experimentally observed solar radiation data received from ARC and SAWS. We find a reasonable comparison with the previously reported values for some of the empirical relations reported earlier suggesting that some of these empirical relations can be used to estimate the solar radiation for the climatic conditions of the Vhembe region of South Africa.