You climb onto your roof or look up at your solar system and notice something alarming:
burn marks, brown streaks, dark patches, melted areas, or scorched spots on one or more of your solar panels.

This is one of the most serious visual warning signs a solar system can show.

Texas homeowners often describe seeing:

• A dark brown or black spot near the edge of a panel
• Burn streaks running across the solar cells
• Melted material near the junction box or wiring
• A single heated area that looks “cooked”
• Panels that look scorched after a hot summer day
• Smoke-like discoloration around specific cells

Burn marks are never normal, and they are never cosmetic.

Burn marks always signal a failure inside the panel or a serious electrical issue underneath the array — sometimes both.

This blog explains exactly what causes solar panel burn marks, why they happen more often in Texas, what they say about your system’s health, and what to do next to prevent further damage or safety risks.

What Burn Marks on Solar Panels Really Mean

Burn marks occur when a part of the solar panel overheats beyond safe limits. Solar panels are designed to reach high temperatures, but not to burn, melt, or discolor.

Here are the most common causes.

1. Hot Spots Forming Inside the Solar Panel

A hot spot happens when one part of a solar cell:

• overheats,
• absorbs too much heat,
• or stops converting sunlight properly.

This creates a localized temperature spike that “burns” the area over time.

Common causes of hot spots:

• Dirt buildup
• Bird droppings
• Shading
• Manufacturing defects
• Cell cracks
• Delamination
• Failed solder points

Hot spots are dangerous because they:

• reduce performance
• accelerate degradation
• cause thermal runaway
• can eventually lead to fire risk

If you see dark patches or burn spots, a hot spot is usually the culprit.

2. Microcracks Causing Cell Failure and Heat Buildup

Microcracks are tiny fractures in the solar cells, often caused by:

• Hail
• Storm debris
• Walking on the panels
• Rapid temperature swings
• Installation pressure

Once a cell is cracked, electricity flows unevenly, causing that section to heat up.

This heat builds over time and eventually causes:

• Burn marks
• Darkened lines
• “Snake-like” discoloration
• Melted surfaces

Texas hailstorms are a major cause of microcrack burn damage.

3. Faulty or Failing Bypass Diodes

Bypass diodes prevent shaded or failing cells from dragging down the whole string.
When a bypass diode fails, a small portion of the panel can:

• overheat,
• short out,
• burn,
• or melt the surrounding material.

Signs of bypass diode failure include:

• One-third of the panel looks darker
• Burn marks near the junction area
• Sudden sharp drop in panel performance
• Panel appearing much hotter than others

A failing bypass diode is a serious electrical hazard.

4. Loose or Damaged MC4 Connectors Causing Arcing

Arcing happens when electricity jumps across a loose connection. This produces:

• buzzing sounds,
• crackling,
• electrical popping,
• and burn marks.

If connectors under the panel are loose, misaligned, or cracked, they can create enough electrical heat to burn:

• the panel surface
• wiring insulation
• surrounding components

Arcing is one of the most dangerous issues in solar systems.

5. Delamination Inside the Panel

Panels are made of layered materials. Over time, heat or moisture can cause the layers to separate.

Delamination creates air pockets that:

• trap heat,
• weaken electrical pathways,
• cause cell discoloration,
• and lead to burnt areas.

If your panel has cloudy, hazy, or milky areas that turned dark or brown, delamination is likely the cause.

6. Moisture Intrusion Causing Corrosion and Heat

Moisture can enter through:

• cracked frames
• worn seals
• impact damage
• compromised junction boxes

Once inside, moisture corrodes internal components, causing:

• electrical shorts
• hot spots
• cell burnout
• rapid degradation

Burn marks often appear after moisture has been inside the panel for months.

7. Connector Failure Under the Array

Burn marks on panels often originate from electrical failures below the surface.

Under-panel components that may burn include:

• optimizers
• microinverters
• wiring
• junction connectors
• rapid shutdown devices

When these overheat, the heat can spread into the panel itself.

Why Burn Marks Are More Common in Texas

Texas is extremely harsh on solar systems due to:

• intense summer heat
• high UV exposure
• rapid temperature fluctuations
• heavy storms
• hail impacts
• humidity swings
• dust and pollen buildup

These conditions accelerate:

• cell cracking
• seal failures
• moisture intrusion
• wiring expansion
• thermal damage

Burn marks often show up first in regions with extreme climates — like DFW.

Is a Burned Solar Panel Dangerous?

Short answer: yes.

Burn marks always indicate:

• electrical overheating
• failing components
• internal damage
• potential fire hazards

Burn marks are one of the few solar issues that can escalate if ignored.

Potential risks include:

• electrical shorts
• arc faults
• panel ignition
• chain reaction failure through the array
• optimizers overheating
• system shutdown

A burned panel should never be left uninspected.

How Burn Marks Affect Solar Performance

A burned panel will:

• produce less energy
• cause string imbalance
• put stress on nearby panels
• reduce inverter efficiency
• create voltage irregularities

Sometimes one burned panel can drag down an entire string.

How to Fix Solar Panels With Burn Marks

Burn marks are not a DIY situation. They always require professional inspection.

Here’s how professionals diagnose and resolve the issue.

1. Schedule a Full Solar Maintenance & Diagnostic Service

A diagnostic service identifies:

• the source of overheating
• whether arcing is present
• optimizer or microinverter failure
• internal panel defects
• hot spot severity
• wiring or junction box issues
• shading influence

Burn marks always need deeper investigation because they indicate failure inside the system.

2. Test Voltage and Current from the Burned Panel

Technicians measure:

• panel output
• voltage stability
• current matching
• bypass diode function

This confirms whether the panel is repairable or needs replacement.

3. Inspect Wiring and Connectors Under the Panel

Burn marks connected to wiring failures require:

• replacing connectors
• rewiring strings
• tightening or reseating MC4s
• inspecting for wildlife damage

Arcing is extremely dangerous and must be corrected immediately.

4. Evaluate Optimizers or Microinverters

If the burn pattern is caused by electronic failure:

• the device will need replacement
• wiring may need rework
• shading patterns may be adjusted

Optimizer overheating is a common cause of localized burn marks.

5. Determine If Panel Replacement Is Necessary

Not all burned panels can be saved. Replacement is required when:

• internal cells are destroyed
• moisture caused severe corrosion
• delamination is advanced
• bypass diodes are burned out
• hot spots cover a large area

Failing panels should be removed to protect the system.

When a Solar Detach & Reset Is Needed

A Solar Detach & Reset (D&R) is recommended when burn marks affect:

• wiring under the array
• multiple connectors
• optimizers or microinverters
• system voltage consistency
• the panel’s structural integrity

A D&R allows full access to inspect and restore all hidden components safely.

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