Identifying Degradation Mechanisms in Fielded Modules using Luminescence and Thermal Imaging.

Recipient NREL (PI: Sulas, Dana)

Subs NREL PVEL

Status Awarded

Abstract Extending lifetimes of photovoltaic modules requires spatially-resolved characterization of the failure areas as well as sufficient statistics to determine how the degradation mechanisms relate to power loss. Currently, many module investigations are based on visual inspection. However, several degradation mechanisms do not create visible defects, such as potential induced degradation, metallization failures, generation of acetic acid from encapsulant degradation, meta-stabilities of module materials, impurity diffusion, and reverse -bias breakdown under partial shading. Even if visible defects are present, these defects do not always correlate with the main cause of failure. For this reason, we propose to use thermal and luminescence imaging to identify causes of performance loss in the field.