Multi hotspot
Several distinct hotspots on a single module. Multiple simultaneous hot cells usually mean widespread cell damage rather than a one-off local defect.
Thermal signature
Two or more separate, sharply bounded bright spots at cell or part-cell scale scattered across one module, each clearly hotter than the surrounding cells. The spots persist in consecutive frames and don't move with the camera angle, which separates them from sun glint.
Typical ΔT
10–30 °C above neighbouring cells at each spot, with severe cases exceeding 40 °C (typical industry interpretation aligned with IEC TS 62446-3).
What causes it
- Widespread cell cracking from hail, transport or handling damage
- Multiple failing solder joints across the cell matrix
- Advanced cell degradation affecting several cells at once
- Heavy localised soiling at several points (verify against the RGB pair)
Power impact
Losses are larger than a single hotspot and the module degrades faster: each hot cell stresses its encapsulant and backsheet, and multi-cell damage tends to spread with thermal cycling. These modules are typically replacement candidates rather than repairs.
Recommended action
Fix: within 30 days
Verify on site within 30 days. Confirm the spots are not surface soiling, run an I-V curve or electroluminescence test to map the cell damage, and prioritise the module for replacement — treat any spot at very high ΔT as an immediate safety-class finding.
Frequently asked questions
Is a multi-hotspot module worth repairing?
Usually not. A single hot cell can sometimes be tolerated and monitored, but several hot cells indicate matrix-wide damage that will keep progressing. The economic answer on most sites is replacement, with the removed module assessed for warranty.
Could multiple hotspots just be bird droppings?
They can look similar, which is why we cross-check against the paired visible-light frame where available. Droppings sit on the glass and clean off; true hotspots come from inside the laminate and persist after cleaning.
Related anomalies
Suspect multi hotspot 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.