| Popis: |
This paper investigates and analyzes dominant defects and degradations observed in 5-year-old desert fielded photovoltaic (PV) modules installed adjacent to a utility-scale site in Dubai, United Arab Emirates. The site experiences high temperature and ultra-violet irradiance, large variations between day and night temperatures, and sand-dust accumulation. The study utilizes a systematic approach to exploit different non-destructive characterization techniques such as, microscopic visual inspection, illuminated current-voltage analysis, electroluminescence and ultra-violet fluorescence imaging for detection and analysis of the observed defects and degradations. Overall, the defects and degradation were classified based on their occurrence at the cell or module level. Herein, structural breakages in finger metallization and cell wafer were observed at different orientations. However, propagation of such defects was more common. Whereas, the more dominant glass abrasions and encapsulant discoloration were seen in the module packaging. The major findings found the direction of glass abrasions to exist dominantly in the site’s prevalent wind direction. Also, all outdoor modules showed encapsulant discoloration in variable shapes and severity. It has been concluded in this study that such defects are not observed under the currently existing environmental standards test protocols. Consequently, the paper highlights the need for the development of standard tests that address the defects commonly observed in desert conditions. |
