Performance analysis of 600 kWp grid-tied rooftop solar photovoltaic systems at strathmore university in Kenya

Abstract

Kenya boasts of abundant solar irradiation potential across its expansive regions, averaging between 4.5 kWh/m2 and 6 kWh/m2 per day. Despite this advantageous condition, solar energy's contribution to the national energy mix remains relatively low. To boost solar energy contribution to the national grid, it is crucial to assess the performance of existing grid-tied solar PV systems and develop strategies to improve their energy yields and further help in designing and installing new plants. This paper presents a technical performance analysis of a 600-kWp grid-tied solar PV system at Strathmore University, monitored over one year between January and December 2019. Economic and thermographic analysis of the solar PV system is done. The performance indices studied according to IEC 61724 standard include performance ratio, capacity utilization factor, reference yield, final yield, total collection losses, and total energy yield. This solar plant generated 735 MWh in 2019. The annual average monthly performance ratio, capacity factor, and annual specific energy yield were 57.4%, 13.97%, and 1225 kWh/kWp, respectively. The annual average monthly final yield, array yield, reference yield, and total system collection losses were 3.37 kWh/kWp, 4.49 kWh/kWp, 5.9 kWh/kWp, and 2.53 kWh/kWp, respectively. The thermographic analysis done shows that the system exhibits healthy temperature distribution. The economic analysis demonstrated Levelized Cost of Energy (LCOE) and simple payback period of US$ 0.143/kWh and 9.1 years respectively. The study reveals that the Strathmore system's performance is similar to other solar plants worldwide.