Maria Ignacia Devoto Acevedo

This study presents a detailed evaluation of electrically conductive adhesives (ECAs) in photovoltaic (PV) modules, focusing on their impact on module power loss under standard accelerated aging conditions used in industry. The study was enabled by using an innovative analytical method to determine the contact resistivity of ECA‐based interconnects that was previously developed as part of this research and provides unique insights into ECA performance in PV modules. The findings reveal that interconnects based on epoxy‐ECA formulations tested in this experiment exhibit significant degradation in contact resistivity during damp heat and thermal cycling tests, whereas interconnects using acrylic‐ECA formulations demonstrate a more stable contact resistivity. Contrary to expectations, no strong correlation was observed between the contact resistivity degradation of ECA‐based interconnects and module power loss, challenging prevailing assumptions about module reliability. This suggests that other factors, such as cell metallization degradation, play a more critical role. Furthermore, encapsulation materials significantly influence module resilience, with the polyolefin elastomer formulation used in this study providing superior moisture protection for cells, while the ethyl vinyl acetate formulation offered better protection for interconnects. These insights underscore the complexities of module reliability, highlighting the need for innovative materials and enhanced testing protocols to ensure long‐term performance. © 2025 The Author(s). IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Our previous work highlighted how microscopic structural effects influence the sheet and contact resistance of electrically conductive adhesives (ECAs). Herein, we delve further by investigating how the contact and bulk resistivity of several ECAs that are based on the same formulation, but with different filler content, are correlated with the filler content. Additionally, two different filler geometries — high and low surface area (HSA and LSA) fillers — are combined in different ratios to maintain a similar viscosity and therefore processability. Hence, contact and bulk resistivities are also correlated with the different geometry ratios of these two fillers. As expected, it was found that the contact and bulk resistivities decreased when the filler content was increased. However, the magnitude of the decrease was found to depend strongly on the filler geometry ratio. At extreme filler geometry ratios, when the bulk is either mostly loaded with HSA‐fillers or mostly with LSA‐fillers, the impact of changes in the filler content on the bulk and contact resistivities is markedly different. The measured data is interpreted within the context of percolation theory and it is determined that the optimum ratio of the LSA and HSA Ag‐fillers investigated in this study is approximately 60:40 (for an epoxy‐based adhesive). This work has important ramifications for the design of ECAs, where cost considerations and the need to reduce silver resource usage demand the lowest (silver) filler content, but the demands of product performance point to higher filler content.

The Atacama Desert receives the highest levels of solar irradiance in the world with an annual average of 2500 kWh/m² for the global horizontal irradiance and 3500 kWh/m² for the direct normal irradiance. One of the challenges is the large portion of ultraviolet light. This part of the spectrum be detrimental for the encapsulant materials, reducing their lifetime. To develop a module adapted to the Atacama Desert conditions, it is imperative to have standardized information from first-hand about the typical faults experienced by photovoltaic modules operating in the desert. This work reports on the design and implementation of the Inspection Data Collection Tool to evaluate crystalline silicon-based moules operating in desert climates. The tool brings together novel features of compatibility with current standards, efficient mobile-type instrumentation (equipment and tools), clear procedures/protocols for non-expert users and low development costs. A total of 95 modules were inspected to characterize failure/degradation issues. Three components of the solar modules were assessed: front cover glass, ethylene-vinyl acetate encapsulant and solar cells. Seven abnormalities were analyzed: Soiling, front cover glass discoloration, encapsulant delamination, hotspots, partial shading, cell fracture and faulty soldering. Soiling was the most common issue, showing correlation between dust deposition and location.