OUTDOOR ELECTROLUMINESCENCE IMAGING OF CRYSTALLINE PHOTOVOLTAIC MODULES: COMPARATIVE STUDY BETWEEN MANUAL GROUND-LEVEL INSPECTIONS AND DRONE-BASED AERIAL SURVEYS

摘要

The electroluminescence (EL) scan is a powerful method to detect solar cells or modules with various defects. The electroluminescence measurement is used by default already in most cell and module production although an international standard determining pass and fail criteria is still missing. Furthermore, so far there was no suitable approach available for large-scale investigation of complete plants over 1 MW. One of the reasons is varying ambient conditions in real power plants that have a significant impact on the EL image quality during data acquisition in field. However, there is an increasing interest and demand in high volume EL-field inspections. Different systems are available, whereas most of them only operate during the night, because of less interfering radiation. In this paper two different methods for high volume EL image capture are compared including the usage of a drone generating EL videos of solar plants. The pros and cons and especially the influence of irradiation, wind and day time are investigated. Exemplarily results are presented obtained in a project where 12500 modules - potentially crack affected - have been investigated. The software-based data analysis revealed that crack-affected cells were mainly located in the center of the modules and PID affected modules were manly located at the edge.