Broken glass
The module's front glass is shattered or cracked. The module may still produce, but moisture ingress degrades it quickly and the electrical insulation can no longer be trusted.
Thermal signature
An irregular, mottled warm region that follows the fracture pattern rather than cell boundaries — often a spider-web or dendritic texture across part of the module. Where moisture has entered, the thermal pattern becomes patchy and changes between inspections; the paired RGB frame usually confirms the shattered glass directly.
Typical ΔT
5–25 °C across the damaged region, irregular rather than cell-shaped (typical industry interpretation aligned with IEC TS 62446-3). Findings escalate toward the safety class because insulation integrity is compromised.
What causes it
- Hail impact
- Thrown or dropped objects, vandalism, mower strikes
- Thermal stress from a severe pre-existing hotspot
- Racking or clamping stress cracking the glass
- Spontaneous tempered-glass failure
Power impact
Output typically degrades progressively as moisture reaches the cells and corrodes the metallisation. The bigger issue is safety: a wet module with broken glass can leak current to frame and ground, creating shock and ground-fault risk for anyone working on the array.
Recommended action
Fix: immediate
Act immediately on confirmed breakage: test insulation resistance, isolate the module or string if it fails, and replace the module. Do not leave a broken-glass module in a circuit that people service, and check neighbouring modules for the same impact event.
Frequently asked questions
The broken module still produces power — why replace it?
Because production is not the constraint, safety and trajectory are. Moisture ingress corrodes the cell metallisation within months, and the compromised insulation can turn the module into a ground-fault source whenever it is wet. It will fail; the only question is whether it causes harm first.
Can thermal imaging find broken glass before it is visible from the ground?
Yes — rows are rarely walked, and breakage on the upper face is hard to see from access roads. The irregular thermal texture of a fractured, moisture-affected module stands out clearly from the air, and the RGB pair confirms it without a site visit.
Related anomalies
Suspect broken glass on your site?
Fly the site, upload the thermal frames, and get every module graded against this taxonomy — severity-ranked, with flagged imagery and per-module locations. Quote your site size in seconds.
ΔT figures and abnormality classes on this page describe the typical industry interpretation aligned with IEC TS 62446-3 — indicative engineering guidance, not normative text from the specification. Temperature differentials are only meaningful when captured at ≥600 W/m² irradiance (per the TS) and verified on site before repair work.