Investigation of Degradation in Crystalline Silicon Photovoltaic Modules After 10 Years Exposition in Senegal by Infrared (IR) and Electroluminescence (EL)

Abstract

The effects of a sub-Saharan coastal climate on PV modules degradation was studied in this paper. A Mono and a polycrystalline-silicone solar PV module exposed in Dakar, dry and coastal climate, at the extreme West of Senegal was studied. As first inspection in this region, the electrical parameters of two PV modules A and B operated during about 10 years, are measured under standard testing condition (STC) and their I-V characteristics were fitted. The initial I-V characteristics was performed under real conditions and translated to STC and compared to the measured I-V characteristics at standard test conditions (STC) obtained in PV Laboratory after exposition. After the operating years, the main important parameters of the studied PV modules: short-circuit current I_SC, open circuit voltage U_OC, maximum power P_MPP, nominal current I_MPP and Voltage VMPP are evaluated and then compared to the initial parameters obtained during initial exposition to estimate their degradation.

Moreover, the defects that affected the PV module are explored by visual inspection, Electroluminescence (EL) and thermography (IR) imaging methods. The results show absolute degradation of maximum power (ΔP_MPP) nearing −5.35% and −2.92% for the mono and polycrystalline silicon operating about 10 years. The inspection reveals many degradations in both modules. Most of the degradations due to the climate are found in the mono and a very advanced I_SC mismatch is found with the IR image. The polycrystalline has many mechanical defects that’s does not too much affect the performance characteristics.