Residual Stresses Affect Cell Fragment Movement

Journal Article · 27 April 2023 · IEEE Journal of Photovoltaics

DOI: https://doi.org/10.1109/jphotov.2023.3269118 · OSTI ID:1975214

Springer, Martin  ^[1]; Silverman, Timothy J.  ^[1]; Bosco, Nick  ^[1]; Joe, Junki ^[1]; Repins, Ingrid  ^[1]

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1. National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Predictive modeling tools such as the finite element method can be of tremendous help in assessing the reliability and long-term performance of photovoltaic modules. In order to obtain accurate results, the proper modeling of materials and manufacturing processes are of utmost importance. Module fabrication introduces thermo-mechanical stresses inside the module laminate, which need to be accounted for as residual stresses in finite element simulations. We found that cell fragment movement and crack opening displacements of fractured silicon cells within modules are affected by those residual stresses. Cell cracking remains a challenging topic in assessing the reliability and durability of damaged modules. Hence, accurately quantifying the separation and movement between cell fragments creates the foundation for establishing reliable lifetime and performance assessments of fractured silicon modules. Here, we present a modeling approach that uses upper and lower bounds to accurately account for the residual stresses introduced by the module lamination process. We designed a four-point flexure coupon test of a laminated, fractured silicon strip to validate our numerical results and found good agreement between our modeling methodology and the experimental data. Finally, we discuss the implications of the residual stresses on the normal crack opening and metallization wear-out of fractured silicon cells.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1975214
• Report Number(s): NREL/JA--5K00-85193; MainId:85966; UUID:cfcdc8fc-5c6a-45b7-b35e-ccb0e0aa93b2; MainAdminID:69369
• Journal Information: IEEE Journal of Photovoltaics, Journal Name: IEEE Journal of Photovoltaics Journal Issue: 4 Vol. 13; ISSN 2156-3381
• Publisher: IEEECopyright Statement
• Country of Publication: United States
• Language: English