ELECTRICAL ANALYSIS AND CHARACTERIZATION BY LBIC AND ELECTROLUMINESCENCE OF CRYSTALLINE SILICON PV MODULES AFTER APPROXIMATELY 20 YEARS OF FIELD EXPOSURE

Abstract

The fast growth of the photovoltaic market in the last years has raised new challenges for the development of standardized tests to assure PV module reliability in the field and to predict their lifetime. These are crucial points to keep the confidence of investors in standard well-established technologies and to increase confidence in new emerging technologies. The analysis of degradation of modules that were field exposed over a long period of time is fundamental to identify the degradation mechanisms and to collect statistics on modules behaviour. This work focuses on the analysis of the change of the PV modules electrical characteristics after approximately 20 years of field exposure, considering differences in the design of cells that were used for the production of these modules, which were identified by detailed visual inspection. Failure modes were identified by comprehensive visual inspection and the use of spatially resolved analysis techniques: Laser Beam Induced Current (LBIC) and electroluminescence (EL) and the effects of differences in cells design were analysed by comparing the degradation rates of electrical parameters.