Solar energy, as one of the main sources of renewable energy, is exponentially increasing capacities in global production. It is expected that due to increase of operational modules, industry will be challenged with fast, simple, accurate and noninvasive diagnostic method. The potential for the method with the described characteristics can be found in error detection with Fluorescence. Fluorescence and Phosphorescence, as types of Photoluminescence, are processes, where material with photoluminescent properties emits light as a result of excitation of atoms with electromagnetic waves. EVA film, as encapsulation material of solar cells, shows distinct fluorescent properties, if illuminated with UV light. Based on the presence and absence of fluorescence in solar cells, status and defects can be estimated.
To run an experiment and analysis of solar modules, I constructed a portable UV flashlight, based on UV light emitting diodes (LED), with rechargeable batteries that enable fast and simple overview of modules located either in the field or in the laboratory. To confirm the possibility of defect recognition, photos of 76 photovoltaic modules from a solar power plant of Faculty of Electroengineering were taken using both Fluorescence and Electroluminescence, as one of additionally recognized diagnostic method. Gathered data were statistically analyzed and shares of different defects in power plant are presented, as well as matching of observable defects with both methods. Matching is present in the majority of cases, and explanation for the possible miss match is provided. On the basis of the gathered data, method of fluorescence can be recognized as one of the easiest and most effective methods for analysis of status of solar cells and modules, with great potential for further development and industrialization.
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