The impact of atmospheric conditions on the sustainability of a PV system in a semi-arid region: A case study from South Africa

Varying atmospheric conditions can exert a significant negative impact on the amount of energy that is produced by a photovoltaic solar system. The purpose of this research is to present empirical data contrasting the available daylight hours of two distinct sites in South Africa, one being a semi-arid region and the other a pollution intensive area. Daylight hours are defined in this paper as the amount of time in which energy equivalent to the STC conditions is being received by a PV module. Both these sites are reported to have the same annual global horizontal irradiation according to available sources. However, the empirical data from this study indicates an average difference of 53% between the daylight hours available for the two sites for March, April and May.