Thermomechanical deformations in photovoltaic laminates

Abstract

Recent experimental results based on the digital image correlation technique (U. Eitner, M. Köntges, R. Brendel, Solar Energy Mater. Solar Cells, 2010, 94, 1346-1351 show that the gap between solar cells embedded into a standard photovoltaic laminate varies with temperature. The variation of this gap is an important quantity to assess the integrity of the electric connection between solar cells when exposed to service conditions. In this paper, the thermo-elastic deformations in photovoltaic laminates are analytically investigated by developing different approximate models based on the multilayered beam theory. It is found that the temperature-dependent thermo-elastic properties of the encapsulating polymer layer are responsible for the deviation from linearity experimentally observed in the diagram relating the gap variation to the temperature. The contribution of the different material constituents to the homogenized elastic modulus and thermal expansion coefficient of the composite system is also properly quantified through the definition of weight factors of practical engineering use.

Application of the first-order shear deformation theory to the analysis of laminated glasses and photovoltaic panels

“…Crystalline or thin film photovoltaic modules currently available on the market are composed from front and back glass or polymer layers and a solar cell layer embedded in a polymeric encapsulant [4][5][6], cf. Figs.…”

A user-defined finite element for laminated glass panels and photovoltaic modules based on a layer-wise theory

“…Crystalline or thin film photovoltaic modules currently available on the market are composed from front and back glass or polymer layers and a solar cell layer embedded in a polymeric encapsulant [4][5][6]. A lightweight design of photovoltaic modules includes front and back panels made from plastics.…”

A geometrical multi-scale numerical method for coupled hygro-thermo-mechanical problems in photovoltaic laminates

“…The EVA polymer displays a strong thermo-visco-elastic constitutive response, as experimentally reported in [5, 6], with a variation of the elastic modulus of up to three orders of magnitude depending on temperature. Generalized Maxwell rheological models used so far generally provide exponential type relations for the relaxation modulus and, in order to approximate the experimentally observed power-law trend, a huge number of elements (and thus of model parameters) has to be taken into account.…”