PV power plant inspection by UAS: Correlation between altitude and detection of defects on PV modules

Photovoltaics (PV) is fast becoming a reliable source to meet energy requirement for human needs. In the last decade, solar energy have expanded their application range to power plants, industry, buildings, telecommunication and space. Visual inspection has represented the first step in PV module monitoring, but rapid advances in Unmanned Aerial Systems (UASs) resulted in facilitating such a procedure in large PV plants´ inspection. However, there is still lack of specific research on UAS in photovoltaic applications due to their novelty, regulation issues and thus further exploring is required to use their entire potential in PV energy field. The main scope of this paper is to investigate correlation between altitudes of aerial photography and possible defect identification on the modules. For this purpose, a light UAS platform was employed to fly up to 20m of flight height in order to capture aerial images of modules using sensor and GPS onboard. The results of this study indicate that PV module defects identification can be classified based on different flight conditions.