Long-term performance and degradation analysis of a 5 MW solar PV plant in the Andaman & Nicobar Islands

Renewable energy is being advocated as a new strategy in response to rising energy demand and global climate change. Solar photovoltaic technology is of great significance to climatic conditions due to the good solar intensity and availability to generate energy. In this paper, the 10-year operating performance of a 5 MW solar PV plant installed in tropical climate of the Andaman and Nicobar Islands was analysed. In 2015, the PV plant achieved its highest electricity production of 7216 MWh, while its lowest, 4757 MWh, was observed in 2022.The maximum performance ratio was recorded as 84.28 % in 2016 due to lower operating cell temperature whereas the maximum CUF as 16.17 % was recorded in 2015. The highest module, inverter and system efficiency for the ten year was observed 12.03 %, 97.64 % and 11.75 % respectively in year 2016. In 2014, the highest values for reference yield, array yield, and final yield were recorded as 4.92, 4.08, and 3.98 kWh/kW/day, respectively. Higher capture losses were observed in the plant over the year which varies upto 1.65 h/d. The plant exhibited a degradation rate of 1.99 % per annum, determined by employing an initial PR of 80.03 %, which declined to 64.11 % by 2022. Degradation analysis of the present system was also performed using visual inspection technique. Mostly found defects in plant was corrosion, delamination of encapsulant material, browning of cell material, burn mark on the back of module, milky patterns, cracks in top facing glass and solar cells. Since, the plant is located in the coastal area, it was seen that the plant is facing a severe issue of algae growth. Some PV modules were covered by more than 90 % algae which significantly contribute in capture losses.