The field performance of a 558 kWp ground mounted single-axis PV system in Pretoria, South Africa

Abstract

According to a recent Green Tech Media (GTM) publication [Moskowitz, 2017], 23% of all ground-mounted photovoltaic (PV) systems are installed on trackers. Trackers are especially beneficial for commercial and utility scale applications, particularly in sunniest parts of the world where the direct normal irradiance (DNI) component of sunlight is relatively high. However, very few studies have been reported on the field performance of single axis tracking systems installed and operated in the Southern Africa region. In this study, therefore, the real-world performance of a 558 kWp ground mounted single-axis PV system at the Council for Scientific and Industrial Research (CSIR) Pretoria campus over a period of 21 months was analyzed. The plant performance was evaluated in terms of the standard performance ratio based on the irradiance in the plane of array and in terms of the performance ratio based on the Global Horizontal Irradiance. It is anticipated that the result of the study will provide useful inputs in assisting system designers, researchers and operators of solar PV plants in South Africa in understanding the optimal operation of solar tracking systems.