Influence of Large Periods of DC Current Injection in c-Si Photovoltaic Panels

Abstract

Nowadays, electroluminescence imaging (Eli) appears as an emerging technique in the maintenance of photovoltaic (PV) plants. There is a concern about how the current injection needed in ELi measurements can affect the PV modules service life, and how these periodical inspections can affect the long term life of the modules. In order to give a practical answer to this problem, a series of tests consisting of long periods of current injection on several monocrystalline silicon modules has been carried out. The modules tested had already fulfilled their useful life and present multiple defects. In order to analyze how the current injection affects the state of the module, images of infrared thermography (IRT) and ELi were acquired during the current injection period. The subsequent analysis of these images shows only a small effect during the heating period in the EL intensity results at the beginning of each test, not affecting the module performance.