Evolution of photovoltaic solar modules dark properties after exposition to electrical reverse stress current inducing thermal effect

Abstract

Purpose -The purpose of this paper is to investigate the dark properties as a function of reverse current induced defects. Dark characteristics of solar modules are very essential in the understanding the functioning of these devices. Design/methodology/approach -Reverse currents were applied on the photovoltaic (PV) modules to create defects. At several time intervals, dark characteristics along with surface temperature were measured. Findings -Current-voltage (I-V) and capacitance-voltage (C-V) characteristics furnished valuable data and threshold values for reverse currents. Maximum module surface temperatures were directly related to each of the induced reverse currents and to the amount of leakage current. Microstructural damages, in the form of hot spots and overheating, are linked to reverse current effects. Experimental evidence showed that different levels of reverse currents are a major degrading factor of the performance of solar cells and modules. Originality/value -These results give a reliable method to predict most of the essential characteristics of a silicon solar cell or a module. Similar test could help predict the amount of degradation or even the failure of PV modules.

Capacitance Evolution of Photovoltaic Solar Modules Under the Influence of Electrical Stress

“…These studies however tackled the problem in the dark conditions. Another study contributed to the effect of heat on the performance of photovoltaic cells and modules, where the heat resulted in the occurrence of reverse currents affecting the I-V characteristics [9].…”

An Overview on Electric-Stress Degradation Empirical Models for Electrochemical Devices in Smart Grids

“…The authors in [36,37] demonstrated microscopic damages (and hot spots) after making flow a minimal reverse current of 10 mA for 10 min through shaded (amorphous silicon) PVMs. Additionally, in [37], a dramatic drop in the shunt resistance (almost a short circuit) for similar test conditions was demonstrated. The authors also showed that the effect is faster under greater temperatures (70 • C) than ambient ones.…”