Influence of Passivation and Solar Cell Configuration on the Electrical Parameter Degradation of Photovoltaic Modules

Abstract

This article analyses and compares the influence of p-type Cz-Si solar cells produced with and without Al-BSF and silicon oxide passivation on the degradation of the electrical parameters of PV modules, after 77 months under operating conditions in a PV system. Solar cells were manufactured at a pilot plant-scale facility, and 32 PV modules with silicon oxide passivated emitter and Al-BSF solar cells were assembled. The other group was composed of 28 PV modules produced with n+pn+ solar cells. The I–V curves of the PV modules were measured under standard test conditions before and after 77 months of exposure. In both groups, the short-circuit current presented higher degradation, and the open-circuit voltage showed low reduction. However, the degradation of these electrical parameters was lower in PV modules assembled with a passivated emitter and Al-BSF solar cells. Consequently, the power degradation rate of PV modules with passivated emitter n+pp+ and n+pn+ solar cells was 0.29% and 0.66% per year, respectively. The milky pattern was observed at the edge of all solar cells and was related to titanium dioxide antireflective coating modification and laser isolation processing.