Deterioration and performance evaluation of photovoltaic modulesin a semi-arid climate

Abstract

PV modules are the most reliable component of a photovoltaic (PV) system. This supposed reliability leads the modules to have a warranty of up to 25 years. With the increasing insertion of PV in the energetic matrix, it is necessary to evaluate and guarantee the reliability of this source. This paper presents an evaluation of degradation in PV modules installed 15 years ago on the roof of the Department of Electrical Engineering, Federal University of Ceará, Brazil. This evaluation uses two methods: visual inspection and analysis to measure degradation degree in electrical properties of the modules. Maximum power (PMPP); Current at the maximum power point (IMPP); Voltage at the maximum power point (VMPP); Short circuit current (ISC) and Open circuit voltage (VOC) are measured using a power curve tracer and compared with manufacturers data. Visual analysis show that delamination and discoloration are the degradations found in most of the modules. Considering the electrical parameters, a MPP reduction of 30% was found.