Inspecting PV-plants using aerial, drone-mounted infrared thermography system

Abstract

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.

Worldwide more than 140 GW photovoltaic plants are installed. The demand for testing methods for quality control of installed photovoltaic modules is increasing. Imaging techniques, like infrared imaging, are very popular. There are several advantages, providing two-dimensional images, measuring during operating conditions, fast and contactless as well as non-destructive. Mounting an infrared camera to a drone enhances the inspection but some specialties have to be considered. There are several factors influencing the image quality, as the observation angle, the flight altitude, the flight velocity which have to be chosen properly. Besides the influence of the measurement parameters, IR-images of PV-plants and single modules will be shown. Depending on the temperature distribution evidence for specific failure modes are given. Thus, cell fracture, soldering failure, short-circuited cells, by-passed substrings, can be distinguished easily using IR-imaging. Further analyses verify the negative impact of the identified defects on the module performance.