PV Backsheet Failure Analysis by Scanning Acoustic Microscopy

Photovoltaic module failure modes associated with backsheet degradation have a high relevance in the operation and maintenance of power plants. In this work, field-exposed modules are analyzed by Scanning Acoustic Microscopy (SAM) to visualize and localize backsheet failure modes in specific layers non-destructively. Acoustic micrographs were collected from material depths of the backsheet and allowed the visualization and assessment of depth profiles of the embedded PV module components individually. Multiple types of interlayer cracks were identified. These local defects of the backsheet were validated by microscopy images of destructively acquired backsheet cross-section samples. Additionally, the backsheet cracking are reproduced in laboratory under UV-DH combined aging test.