Correlation between Elevated Wind Speed and Rear Glass Breakages on Non-large-format Bifacial PV Modules on Trackers in a Solar Farm

Darryl Wang, Andi Hermawan, Evan Woolard DNV Singapore Pte. Ltd., Singapore, --, Singapore

To the authors’ knowledge, this is the first report with onsite-recorded evidences suggesting that not-high but elevated wind speed is a major influence on or a trigger for large-scale (>15%) rear glass breakages on bifacial PV modules mounted on trackers in a solar farm located in the Asia Pacific region. Time and spatial correlations were found between elevated wind speed records and rear glass breakages on non-large-format glass/glass bifacial PV modules mounted on single portrait (1P) single-axis trackers. For time correlation, intra-day elevated wind speed clusters were found to consistently precede major onsite O&M events that includes or can be related to glass breakages. Good spatial correlation was also observed, where the areas with highest glass breakage concentrations were found close to a weather station that accounts for ~75% of all the elevated wind speed records.  The maximum wind speed is, however, well below thresholds that can exert wind load exceeding the typical module design wind load, representing an engineering missing link that is consistent with other works. The glass crack patterns found onsite are also discussed. It is hoped this work can help the PV R&D community to sharpen the focus towards finding the missing link.