Preliminary Identification of Functional Decommissioned Solar Photovoltaic Modules from Solar Farms: A case study in Thailand

Abstract

Some decommissioned solar photovoltaic (PV) modules from solar power plants are still well-performed and worth reusing. Test procedure and conditions to separate between functional and expired modules is thus key points. This study has proposed a 3-step process; 1) visual inspection, 2) insulation test and 3) outdoor current-voltage (I-V) curve measurement, to preliminary screen and divide modules into six groups: A+, A, B, C, D and F. The review criterion covers quality, safety and reliability aspects. All processes have been carried on-site and test results have been recorded in a software tool called ‟Solar Sure”. 258 retired PV modules from six solar farms in Thailand has been surveyed. It was found that some multi c-Si modules showed very low insulation resistance. 74% of the total amount of modules in this study still have the maximum power output of above 70% of their initial value, suggesting a potential for second use. The observed results of this preliminary survey are informative for a further study on field-aged PV reliability in the tropics and also useful for a preparation of a guideline for promoting reuse of decommissioned functional PV modules in Thailand.