Solar panels are built to withstand harsh weather, intense sunlight, and years of outdoor exposure. But even the strongest solar panels face a hidden threat that most homeowners never hear about until something goes wrong: hot spots.

A hot spot occurs when part of a solar panel becomes significantly hotter than the rest. It might start as a small issue — a little shading, a bit of dirt, or a weak connection — but over time, hot spots can damage solar cells, reduce efficiency, strain your inverter, and even shorten the lifespan of the entire system.

Hot spots are especially common in Texas because extreme heat, pollen buildup, seasonal shading, and heavy storms all create the perfect conditions for temperature imbalance within the panels.

If your solar production has dropped, if your monitoring app shows inconsistent numbers, or if your solar installer mentioned “uneven performance,” hot spots may be the reason.

This blog explains what hot spots are, why they happen, how they affect your system, and what homeowners can do to prevent them.

What Are Solar Panel Hot Spots?

A hot spot occurs when a section of a solar panel stops producing electricity but continues receiving sunlight. Instead of generating energy, the affected cells absorb heat, creating a pocket of elevated temperature.

Over time, hot spots can:

• Damage the solar cells
• Melt or weaken internal materials
• Create microcracks
• Stress bypass diodes
• Reduce voltage output
• Cause long-term panel degradation

Hot spots often start small but grow if left untreated.

Why Hot Spots Are a Major Problem in the Texas Climate

Texas has several unique conditions that increase the likelihood and severity of hot spots:

• Extreme summer temperatures
• Dust, pollen, and pollution
• Storm debris and high winds
• Rapid weather swings
• Heavy bird activity
• Seasonal shading

Panels in Texas run hotter than in most states — meaning temperature differences inside the panel can quickly lead to damage.

1. Dirt, Dust, and Pollen Buildup

The number one cause of hot spots in Texas is dirty panels.

Dust and pollen create uneven shading. Even a small patch of buildup:

• Blocks light
• Raises temperature
• Forces surrounding cells to overcompensate

This mismatch creates a localized hot spot.

Dirt problems worsen when:

• Panels haven’t been cleaned for months
• Pollen season peaks
• Bird droppings remain on the glass
• Mud or construction dust settles

Left untreated, dirty panels can develop permanent degradation.

2. Partial Shading at Specific Times of Day

Hot spots often occur when:

• Tree branches shade part of the array
• Chimneys or vents cast shadows
• Neighboring houses block afternoon sunlight
• Seasonal sun angles change

Even shading as small as a handprint can cause hot spots.

Texas homeowners often experience seasonal shading changes — especially in winter — which leads to new hot spot issues each year.

3. Microcracks in the Solar Cells

Microcracks develop from:

• Hail
• Roof movement
• Thermal expansion
• Heavy foot traffic on the panels
• Installation errors

These microcracks disrupt current flow, which creates temperature imbalances that turn into hot spots.

Microcracks often go unnoticed until production drops significantly.

4. Faulty or Aging Bypass Diodes

Bypass diodes protect solar panels from shading. When a diode fails:

• Current flows unevenly
• Heat builds quickly
• Entire cell groups become hot

Bypass diode issues are one of the most dangerous causes of hot spots.

These problems become more common as systems age.

5. Loose Wiring or Connectors Under the Panels

Loose connections cause:

• Uneven voltage
• Increased resistance
• Heat buildup
• Intermittent production

When wiring becomes loose or damaged, parts of the panel heat up because the electricity is not flowing correctly.

Loose wiring often occurs due to:

• Texas heat
• Wildlife damage
• Storm vibration
• Poor installation

This is a leading cause of hidden hot spot development.

6. Bird Droppings and Nesting Material

Bird droppings are extremely opaque and block more sunlight than dirt.

Bird nests under the panels also:

• Restrict airflow
• Create trapped heat pockets
• Damage wiring
• Increase panel temperatures

Texas rooftops are a hotspot for nesting birds, especially near solar arrays.

7. Water Intrusion or Moisture Damage

Moisture enters through:

• Cracked backsheet
• Damaged sealant
• Failed edge bonding
• Junction box leaks

Once moisture reaches the cells, electrical resistance increases — which leads to overheating and hot spots.

Moisture issues worsen after heavy rain or hail.

Signs Your Solar Panels May Have Hot Spots

Most homeowners cannot physically see hot spots — they’re inside the panel. However, several symptoms reveal the presence of hot spots.

1. Sudden production drops

Especially during full sunlight.

2. Sharp dips at certain times of the day

Often heat-related or shade-triggered.

3. One string producing significantly less

A classic sign of uneven heating.

4. Unusual patterns on the monitoring graph

Hot spots create daily “valleys” in production.

5. Inverter warning messages

Such as:

• Voltage faults
• High temperature alerts
• String imbalance errors

6. Higher electric bills

Even though the system appears to be working.

7. Burnt smell or buzzing sounds under sunlight

This requires immediate professional attention.

How Hot Spots Damage Your Solar System Over Time

Hot spots start small but grow over time, eventually impacting your entire system.

1. Accelerated Panel Degradation

panels lose efficiency faster than normal when exposed to repeated heat stress.

2. Microcracks Spread Across the Cell

Heat expands cracks, causing long-term production loss.

3. Burned Backsheets

In severe cases, hot spots can burn through the panel backsheet.

4. Bypass Diode Failure

Once bypass diodes fail, shading or dirt creates even more heat.

5. Damaged Wiring or Connectors

Heat weakens wiring insulation, leading to bigger electrical problems.

6. Inverter Stress

The inverter tries to compensate for uneven voltage, reducing its lifespan.

How Texas Homeowners Can Prevent Hot Spots

You can’t control the Texas climate — but you can protect your solar system.

1. Get Regular Solar Panel Cleaning

Cleaning prevents:

• Dirt-based shading
• Pollen buildup
• Bird-dropping hot spots

Clean panels run cooler and produce more power.

2. Schedule Annual Solar Maintenance

Maintenance checks reveal:

• Loose connectors
• Wiring issues
• Diode damage
• Early shading problems
• Hot spots forming under the panel

Annual maintenance is the best defense against long-term heat damage.

3. Trim Trees That Cause Seasonal Shading

Tree growth changes shading patterns every year. Removing shade prevents temperature imbalance.

4. Improve Airflow Beneath the Panels

Good airflow reduces heat buildup.

Technicians can:

• Adjust panel spacing
• Fix sagging wires
• Correct rail alignment

Better airflow → lower temperatures → fewer hot spots.

5. Inspect the Array After Hail or Storms

Hail is a leading cause of microcracks in Texas. A quick post-storm inspection prevents further damage.

When a Solar Detach & Reset Is Necessary

Some hot spot issues can only be fixed by removing the panels.

A Solar Detach & Reset (D&R) is needed when:

• Wiring under the panels is damaged
• Wildlife nests are causing heat pockets
• Moisture has entered the array
• Bypass diodes are failing
• Panels need realignment
• Connectors need replacement

A D&R gives technicians access to hidden components and allows them to restore safe, balanced operation.

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