| Work Detail |
Indonesian scientists have investigated the first operational defects of a 24.9 MW solar PV system on the island of Sumatra and identified hot spot formation as the dominant defect. They also detected 282 cases of glass cracks, 350 cases of junction box failures and shading effects related to module defects. Researchers at the University of Surabaya in Indonesia have conducted a study on the first operating defects of a 24.9 MW photovoltaic solar plant located on the island of Sumatra, west of the country. The analysis began in August 2022, when the facility became operational, and was concluded in August 2024. “The relatively short operating period ensures that the observed defects are primarily due to early operational factors, rather than long-term wear,” explained lead author Elieser Tarigan. “This research aims to categorize and quantify the types of defects observed, including the effects of hot spots, glass cracks, junction box failures, and fogged or discolored glass, to understand their impact on system performance.” In total, the Sumatra site has 64,140 photovoltaic panels, each with a capacity of 390 W. They are all installed on the ground and the modules are connected in series to form strings. Each string consists of 30 modules connected in series. “During field observations, the operating voltage and current were monitored and compared to the module’s technical specifications to detect any irregularities,” explains the researcher. “The observations focused on identifying anomalies in the output power of specific module strings. A string was considered abnormal when the output power displayed by the inverter was significantly lower than the theoretical values ??calculated for the string under the given environmental conditions. These anomalies were further investigated to determine the presence of defects in the modules.” Next, investigation of specific modules included visual inspections with direct measurements, and further analysis included detailed measurements and thermal imaging. Data collected from visual inspections and measurements were analyzed to determine the prevalence and impact of each defect type. “The results of the observations indicate that in the first two years of operation, out of a total of 64,400 installed PV modules, approximately 678 modules exhibited operational anomalies caused by various defects mentioned above,” the scientists explained. “The observed failure rate of approximately 1.05% highlights the importance of early monitoring and maintenance to ensure the reliability and longevity of PV systems.” According to the results, most of the problems were related to the formation of hot spots. Specifically, 350 junction box failures, 282 cases of glass cracks, 42 cases of junction box swelling, and seven cases of fogged or discolored glass were detected. In addition, cases of shading by surrounding objects such as trees, poles, and buildings, and self-shading between photovoltaic panels were also detected. “Through analysis, it was shown that half-cut modules perform better than full-cell modules in mitigating the effects of hot spots due to their lower current per cell and better configuration of bypass diodes, which reduces heat dissipation and power losses,” Professor Tarigan concluded. “In addition, reducing the number of modules in a string effectively lowers the voltage and current of the string, thereby minimizing the severity of hot spots.” Their findings were presented in “ Identification of early operational defects in photovoltaic modules: A case study of a 24.9 MWp solar PV system in Sumatra , Indonesia,” published in Unconventional Resources . |
