Core Objective 4: Fielded Module Forensics

As a core objective, DuraMAT studies fielded module forensics—the quantification and characterization of photovoltaic (PV) module failure modes during outdoor exposure and the study of materials and performance properties changing over time during testing and deployment.

Fielded module forensics includes a wide variety of structural, chemical, morphological, electrical, mechanical, and compositional materials characterization tools and the development of reference libraries for module materials.

One of the biggest challenges to studying degradation or failure in fielded modules is that frequent absence of a “reference” module or material. It is difficult to find out what went wrong when we don’t know what it should look like. This core objective will enable researchers to better understand PV material durability and elucidate degradation mechanisms, in addition to generating practical, multi-modal data that guides next steps in materials and module design.

The core objective will also include a study of cell cracking in fielded modules, a non-destructive test method to monitor the generation and evolution of stresses in encapsulated cells and modules, and development of an imaging protocol to identify the degradation mechanisms in fielded modules.

Key Results

Demonstration of an accelerated testing method capable of identifying materials and design field failures that are not captured by existing standard tests. The application-based, unbiased (e.g. derived from the diurnal cycle) C-AST method was demonstrated to identify multiple failure modes (e.g., backsheet cracking, interconnect corrosion, LeTID) observed in PV installations.
Post-examination of specimens (DECS, optical mapping, voltage ionization & UV-LID projects) has confirmed degradation mode(s) resulting from accelerated testing and revealed mechanism-specific insights to improve the understanding and the corresponding degradation rate model(s).
Identification and quantification of the effects of UV exposure and UV contributions to known degradation modes.