Spectral distribution on photovoltaic module performance in South Africa

The ever growing demand for clean energy source has been one of the main agenda in developed countries, but in recent past, however, developing countries have realized the need to supplement their existing grids since demand is growing at a much faster rate than capacity can sustain. Although South Africa is one such country, not enough resources are being developed as current PV systems. PV industries have stretched its wings to Africa, where large and small solar home systems are currently being implemented. The difference in operating conditions from the Standard Testing Conditions (STC) of 1000W/m², AM 1.5 and 25 °C cell temperature has been extensively studied and documented. A lot of work has been done in assessing the performance of PV modules in real operating conditions. The effect of varying outdoor irradiance, temperature and spectrum different from STC has been the main cause of poor module performance and system failure. Most of the work in investigating the effect of changing spectrum during the course of the day has been conducted within the northern climate. The difference in climatic condition between the northern and the southern hemispheres, especially in the sub-Sahara region evidently influence in the performance of PV modules. Different PV module technologies currently in the region market are deployed outdoor and their spectral response is closely monitored as the sun ‘journeys’ from sunrise to sunset. The results reveal that a-Si module is more affected with changing spectral conditions.