Title:	Numerical Analysis on Cell Crack Initiation due to Thermomechanical Stresses
Author(s):	L. Papargyri, P. Papanastasiou, G.E. Georghiou
Keywords:	Finite Element Analysis (FEA), Cracks, Silicon, Stresses, XFEM
Topic:	Photovoltaic Modules and BoS Components
Subtopic:	PV Module Design, Manufacture, Performance and Reliability
Event:	37th European Photovoltaic Solar Energy Conference and Exhibition
Session:	4AV.1.37
Pages:	1038 - 1046
ISBN:	3-936338-73-6
Paper DOI:	10.4229/EUPVSEC20202020-4AV.1.37
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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During PV module manufacturing, the solar cells are thermomechanically loaded and therefore residual stresses are induced. These significant residual stresses combined with additional stresses due to mechanical loads can lead to cell cracks which may not affect the electric efficiency initially but over a period of time the effect may become significant as PV modules are subjected to environmental loads in the field. Therefore, the study of the accumulation of residual stresses and strains from each life stage is of great importance in order to improve the reliability and thus the lifetime of crystalline silicon (c-Si) PV modules. An advanced 3D coupled thermomechancal structural numerical model considering the manufacturing processes and the subsequent mechanical and thermal loading phases in a consecutive stepby-step manner is developed using the finite element modelling approach. The present study is carried out for an in-depth investigation on the effect of the thermomechanical behaviour and stress distribution on the crack sensitive regions in PV modules during their entire life. The results are useful for optimisation of material properties and the development of advanced design strategies.