Thermography of Photovoltaic Panels and Defect Detection Under Outdoor Environmental Conditions

This paper investigates the possibility of detecting defects in photovoltaic (PV) cell and panels under harsh outdoor environmental conditions with the help of synchronized thermography (ST). Infrared (IR) images are obtained under changing solar radiation levels, moderate wind speeds and ambient temperatures below zero degree Celsius with the help of a portable IR-camera. We demonstrate that IR-images obtained under harsh environmental conditions provide the same information as IR-images recorded under common environmental conditions. We elaborate the differences in parameters such as measurement time and region-of-interest (ROI) which need to be adjusted when carrying out measurements under harsh conditions. Our technique allows maintenance staff to carry out measurements, both, during summertime and wintertime, on the site of a PV power plant to identify PV panels with potential defects.