Analysis of measured and simulated performance data of a 3.2 kWp grid-connected PV system in Port Elizabeth, South Africa

• Comparisons between actual measured and simulated performance of a grid-connected PV system.
• Simulation using measured climate data sets gave good monthly energy yield comparisons to the measured.
• The measured performance ratio of 84.3% shows vast solar energy potential in Eastern Cape region of South Africa.
• Better annual specific yield is observed in this study compared to other studies internationally.

This paper analyzes and compares the actual measured and simulated performance of a 3.2 kWp grid-connected photovoltaic system. The system is located at the Outdoor Research Facility (34.01°S, 25.67°E) at the Nelson Mandela Metropolitan University (NMMU), South Africa. The system consists of 14 poly crystalline silicon modules connected in two strings of 7 series-connected modules, each facing north at a fixed tilt of 34°. The data presented in this study were measured in the year 2013, where the system supplied a total of 5757 kW h to the local electric utility grid. The performance of the system was simulated using PVsyst software using measured and Meteonorm derived climate data sets (solar radiation, ambient temperature and wind speed). The comparison between measured and simulated energy yield are discussed. Although, both simulation results were similar, better comparison between measured and predicted monthly energy yield is observed with simulation performed using measured weather data at the site. The measured performance ratio in the present study is 84% which is slightly higher than values of 74%, 81.5%, 67.4%, 70% and 64.5% reported is Khatkar-Kalan (India), Dublin (Ireland), Crete (Greece), Karnataka (India) and Malaga (Spain), respectively.