Sequential Accelerated Stress Testing Identifies Processing Defects in Bifacial Photovoltaic Module Packaging That Limit Durability

We use sequential stress testing to investigate hurdles to bifacial silicon photovoltaic (PV) module durability stemming from lamination defects when processing is not optimal. We test modules with glass/glass (G/G) and glass transparent-backsheet (G/TB) constructions using either EVA or POE encapsulants under a modified IEC 63209â ‘sequential stress procedure designed to elucidate delamination degradation modes. This modified stress sequence consists of multiple iterations of damp heat (DH200), fullâ ‘spectrum light exposure (A3â ‘1000/2000), thermal cycling (TC50), and humidity/freeze (HF10). We compare degradation under this accelerated stress procedure with outdoor exposure. Our results highlight both the utility of this new sequential stress testing procedure to uncover possible degradation modes in bifacial PV, as well as the importance of lamination defects that must be avoided to ensure durability as the industry adopts G/G or G/TB bifacial module packaging architectures.