Assessing Degradation in Bifacial Photovoltaic by Sequential Stress and Outdoor Aging

Bifacial photovoltaic modules are increasing in deployment due to advantages in energy generation, and these advanced module packaging architectures present new reliability considerations. Here, we study bifacial packaging architectures and assess the effects of module processing quality, rear-side module coverings, and polymer encapsulant chemistry on aging and degradation. We determine that mini-modules aged by accelerated testing adapted from IEC 63209-2 show similar degradation trends to nominally identical modules aged outdoors. We find lamination processing conditions have a significant effect on early degradation. We investigate degradation modes non-destructively using luminescence imaging, current-voltage performance, and external quantum efficiency. Finally, we assess chemical and mechanical characteristics of various encapsulant formulations to compare adhesion changes that may result in cell delamination.