Inequalities in photovoltaics modules reliability:From packaging to PV installation site

In recent years, the determination of the reliability of photovoltaic (PV) modules has been of ubiquitous interest to the PV industry. Therefore, this work reports on the reliability and degradation mechanism of 186 PV modules from packaging to installation stage. The paper shows that no cracks or hotspots affecting the PV modules before the packaging stage, while a minor reduction in the output power was observed at ±0.3%. The same PV modules were delivered using standard practice, and no further precautions were considered. Electroluminescent (EL) images of all PV modules were taken at the PV installation site, and it was discovered that 2.2% evolved cracks. Depending on the crack size, the estimated output power losses under standard test conditions varied from 0.53% to 1.43%. Furthermore, the PV modules were thermally inspected six months after being installed. It was found that hotspots developed in all the cracked PV modules, and their temperature increased from 10 °C to 20 °C. In addition, a potential induced degradation (PID) test was performed on the cracked PV modules and compared with a crack-free module. It was found that PID affected the modules with cracks more than the crack-free module.