A multimodal analysis of degradation processes in 10W PV panels under thermal and mechanical stress

The worldwide adoption and efficiency of solar energy production rely strongly on the longevity and performance of photovoltaic (PV) panels. There is a need to detect and quantify degradation of PV panels over limited timescales, both for research and development of PV technologies and for early detection of degradation in operating and maintaining PV farms. This paper reports a systematic study of thermal and mechanical stress applied to 10W PV panels, studied by a suite of three measurements: current–voltage (I–V), electrochemical impedance spectroscopy (EIS), and electroluminescence (EL) imaging. While 300 thermal heating and cooling cycles produced minimal change to the I–V curve, significant changes were detected by the other measurements in the series resistance, shunt resistance , and electroluminescent area of the panel. All three measurements saw changes due to mechanical impacts. This study shows how insights can be gained from assessing the changes observed in different measurements. In addition, this work highlights the benefits of using such multimodal analysis to obtain early signs of panel degradation, well before they become apparent in the panel's power output , for categorizing PV panels and in decision-making for reliability enhancement of PV farms. • 10W PV panels were subjected to thermal cycling and mechanical impacts. • Panels were measured with current-voltage (I-V), electrochemical impedance spectroscopy (EIS) and electroluminescence (EL). • Large changes were seen in EIS and EL parameters, smaller changes in I-V. • Comparing results offers insights into the types of degradation produced by the stress. • Results show the benefits of multiple measurements on whole PV modules for early signs of degradation.