Measuring thermomechanical displacements of solar cells in laminates using digital image correlation

authored by

Ulrich Eitner, Marc Köntges, Rolf Brendel

Abstract

Solar modules are commercially fabricated for more than 30 years but there is little knowledge about its thermomechanical properties. Solid materials shrink or expand when subjected to temperature changes. The coefficients of thermal expansion (CTE) for silicon and glass are small compared to the CTE of the polymer sheets. This CTE-mismatch leads to mechanical stress and strain which can be critical for the solar cells, the interconnects and the polymers. We demonstrate that the digital image correlation technique (DIC) is capable of measuring displacements in modules that are within a climate chamber by an optical measurement through a transparent back sheet and one layer of encapsulation material. As a first demonstration the change of the gaps between adjacent cells is determined at various temperatures for three test laminates with three different interconnection techniques. We find the gap between two solar cells to deform about 0.4 - 0.6 μm/° C in the temperature range of 0°C to 80°C and slightly less in the temperature region below 0°C. The results are verified by a simplified calculation of the gap deformation.

Organisation(s)

Institute of Solid State Physics

External Organisation(s)

Institute for Solar Energy Research (ISFH)

Type

Conference contribution

Pages

1280-1284

No. of pages

5

Publication date

2009

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Control and Systems Engineering, Industrial and Manufacturing Engineering, Electrical and Electronic Engineering

Sustainable Development Goals

SDG 13 - Climate Action

Electronic version(s)

https://doi.org/10.1109/PVSC.2009.5411248 (Access: Closed)