Skip to content

Thermal Findings — Case Library

EXPANDING

This page is a growing library of thermal imaging findings from Wadadli Solar field inspections. Each entry documents the thermal pattern, diagnosis, and recommended action.

Thermal Pattern Library

Pattern 1 — Hot Cell (Single Cell, Isolated)

Appearance: One very hot spot within a panel — typically a small square or rectangle significantly hotter than the rest

Delta T: Often 20–40°C above neighboring cells

Diagnosis: Cracked cell, delamination, or internal short circuit

Action: Document, measure delta T, photograph visible and thermal. Flag for panel replacement. Potential warranty claim.

Pattern 2 — Hot Row (One-Third of Panel Hot)

Appearance: Approximately one-third of a panel is significantly hotter than the rest

Delta T: 10–25°C

Diagnosis: Bypass diode activated — shading, soiling, or failed cell group is causing the bypass diode to conduct

Action: Investigate cause of bypass diode activation. If soiling: clean and retest. If shade: document and analyze. If no obvious cause: escalate.

Pattern 3 — Uniform Module Hotter Than Neighbors

Appearance: Entire panel is uniformly elevated in temperature vs. its string neighbors

Delta T: 3–10°C

Diagnosis: Cell-level mismatch, module degradation, or soiling (if thermal is proportional to soiling pattern)

Action: Compare production data for that module. Inspect for soiling. Consider module replacement if production data confirms degradation.

Pattern 4 — Hot String vs. Neighboring String

Appearance: One entire string is noticeably hotter (and likely producing less) than adjacent strings

Diagnosis: String-level issue — broken optimizer chain, combiner input problem, or systematic issue with that string

Action: SolarEdge GO string analysis. Measure string voltage/current. Identify the fault in the string.

Pattern 5 — Hot Junction Box

Appearance: The junction box (black box on back of panel) is significantly hotter than the panel face

Diagnosis: Internal bypass diode failure, failing junction box component, or arc starting inside the box

Action: Critical finding. Document and escalate immediately. Do not clear without identifying the cause.

Pattern 6 — Hot Connector (Visible in Connector Area)

Appearance: MC4 connector or wiring connection area elevated in temperature

Diagnosis: High-resistance connection — loose, corroded, or damaged connector

Action: Isolate system per LOTO, inspect connector. Replace if damaged or corroded.

Building This Library

Every thermal inspection should contribute to this library. When you capture a thermal finding that fits a known pattern, note the case here. When you capture something unusual or new, document it in full — it becomes a new pattern entry.

Include: thermal image, visible-light image, delta T measurement, site, date, outcome.