Breakage in Bifacial PV Modules

This work presents the occurrence of glass cracking in bifacial photovoltaic modules installed at the São Paulo campus of University of São Paulo. One of the systems consists of 78 bifacial modules (545 Wp) arranged in six strings connected to a 35 kW inverter with a single-axis tracker. Within the first month of operation, two modules exhibited cracks in the rear glass. Over the following months the number of PV modules with cracks increased to 20 (25.6%) in 14 months. To gain understanding of the reasons for the glass cracking events, after discussions with the supplier and manufacturer, a second system with 30 modules (545 Wp) of the same maker and model was installed on a fixed-tilt structure. In the fixed-tilt system cracks were observed in nine modules after 10 months of installation (30%). This study documents the cracking patterns in both systems and compares their occurrence to better understand the underlying causes.