Most Common Solar Panel System Faults and Their Solutions

Solar panel systems are a great investment, but they’re not without their challenges.

If you’re like me, you want your system to run efficiently for as long as possible.

And how to fix them before they escalate into costly problems.

I’ve encountered issues ranging from improper installation to overheating, and knowing the solutions has saved me both time and money.

Whether you’re just starting out or looking to optimize your system, this blog will guide you through the most common solar panel faults and their solutions.

If you’re also interested in making the most of your solar investment, check out my Top Tips for Using Solar Power Effectively or learn what Common Mistakes People Make Before Installing Solar.

Poor Installation or Wrong Orientation Can Drag Down Your System’s Performance

Before installing solar panels, it’s important to inspect your roof thoroughly. I learned this firsthand when my roof’s age caused unexpected issues.

If the roof is too old, damaged, or not structurally sound, you could end up with problems like leaks or even roof failure.

Solar panels need to be securely attached using the right mounting systems. I highly stress this step carefully, as improper mounting could lead to costly repairs.

Equally important is positioning the panels correctly. They need to face the sun’s path (south-facing) to work efficiently.

If you don’t get the installation right, you’ll likely face constant problems, which can wear out the panels and other equipment faster. That’s why careful planning is key.

Micro-cracks in Solar Cells

Micro-cracks are tiny fractures in the solar panel cells or their protective layers. I’ve seen how these cracks can happen due to wind, birds sitting, or even during shipping and installation.

When the panels bend or angled, the cells inside can break.

These small cracks can mess with how electricity moves through the panel. This means less energy is produced.

In fact, a panel with micro-cracks can lose up to 20% of its power over time (Read more here).

While visual checks aren’t perfect, they can still help spot clear signs of damage or wear.

Regular inspections are a simple way to catch problems early.

Snail Trails (Gray Marks on Your Panels)

Snail trails, also called “snail tracks” or “worm marks,” are a problem you might have noticed on solar panels over time.

They show up as dark, wavy lines. These lines usually happen because moisture gets into the panel through tiny cracks or weak spots.

It causes a chemical reaction that leads to discoloration (color change).

Look for dark or brown streaks, especially near the edges or around the busbars. These can be signs that snail trails are forming.

Small cracks on panels aren’t easy to see. I recommend using your phone’s camera for a closer look.

Unfortunately, once snail trails appear, they can’t be undone. That’s why regular checks are so important to catch problems early.

Your Panels Might Get Damaged by Severe Weather

If you want to protect your solar panels from storms, start by focusing on the mounting structure.

I’ve found that high winds can cause serious damage if the mounting isn’t strong enough. That’s why it’s so important to use a sturdy system.

Hail can also be a concern, especially if the stones are larger than 1 inch in diameter.

Research shows that the risk of damage is usually low—less than 5% for most systems. However, it’s still something to keep in mind.

Solar panels are waterproof and can handle heavy rain. But over time, water can cause problems if dirt and debris build-up. I always make sure to keep my panels clean to avoid this issue.

Improper Earthing Can Cause Your Solar Panels to Catch Fire Due to Lightening

Though rare, a direct lightning strike can cause serious damage to solar panels and inverters.

The heat from the strike can melt them. If there’s no solid earthing, solar panels are at higher risk.

Poor grounding also increases the chance of static electricity building up. This can make things worse during thunderstorms (possibly leading to electrical discharge).

To stay safe, it’s important to have a strong grounding system in place.

This usually means installing a grounding rod deep into the ground (commonly known as a surge arrestor) and connecting it to the solar panel frame with thick copper wire.

Potential Induced Degradation (PID)

PID, or potential-induced degradation, happens when a voltage difference between the solar cells and parts like the glass or aluminum frame causes performance to drop.

It’s important to note that how you arrange the solar panels can make PID worse, especially if they’re in series strings.

Humidity and heat speed up this process by allowing ions to move more easily within the panel.

If your system runs at higher voltages, like 1000 to 1500 volts, the risk of PID goes up because the potential difference between the panels and the ground gets bigger.

To reduce this risk, make sure your system has proper grounding. I also recommend using transformer-based inverters, which provide isolation and help lower the chances of PID.

It’s a small step that can make a big difference in keeping your panels efficient.

Electrical Connection Issues

Over time, the wires connecting solar panels become loose or even disconnected if not installed properly.

I’ve seen how damaged wires can lead to bigger problems like ground faults or short circuits. This can not only hurt system performance but also create fire risks.

Ground faults can trip circuit breakers that cause power outages.

The good news is that all inverters come with sensors to detect these faults. If one is found, the system automatically shuts down until it’s fixed.

To prevent wire damage, I suggest using protective measures like conduit or buried in the ground. These simple steps help keep your system safe and running smoothly.

Overheating Panels Can Cause Efficiency to Drop

Regularly check the energy output of your solar panels. A big drop in production, especially during peak sunlight, can be a sign of overheating.

If you can, use an infrared thermometer to measure the surface temperature. If the panels get above the 25°C-45°C range, they start to lose efficiency.

Once they hit 70°C (95°F), the energy loss can be even more serious.

I’ve seen people install panels too close to the roof, thinking it helps protect from wind damage.

But that’s not the case.

There should always be enough space between the panels and the roof for proper airflow.

For larger setups, adding heat sinks or small fans can help cool the panels and improve performance.

Your Panels are at Risk of Theft or Tampering From Strangers

Be ready for anything—solar panel theft is becoming more common.

Here are some DIY (easy-to-apply) techniques to protect your panels:

• Replace regular screws with security fasteners that need special tools to remove. This makes it harder for thieves to steal your panels quickly.
• Install motion-activated lights around your solar panels. Thieves don’t like bright lights, and it can stop them from trying.
• Set up CCTV cameras (which are more affordable now) to monitor the area around your solar panels.
• Connect your solar panels to an alarm system that goes off when tampering is detected.

Battery Over-discharging and Heating Can Lead to Early Failure

Overcharging a battery can cause it to heat up because of increased internal resistance. This heat buildup can lead to something called thermal runaway.

If this happens, the battery might swell, leak, or even catch fire.

Over-discharging has its own warning signs. One sign is voltage drops. If you notice your battery’s voltage is consistently below recommended levels, it’s likely being over-discharged.

Another sign is swelling or deformation. If your battery changes shape, it’s a clear sign of overheating or internal damage.

Thankfully, a Battery Management System (BMS) can help. It can automatically disconnect the load when the voltage gets too low. It also manages charging cycles to prevent overcharging.

To keep your battery healthy, use a multimeter to check the voltage regularly. For lithium batteries, make sure they stay above 3.0 volts per cell.

For lead-acid tubular batteries, aim for at least 2 volts per cell. Regular checks can prevent major issues and extend your battery’s life!

Faulty Charge Controllers: Your Battery’s Worst Enemy

A faulty charge controller can allow batteries to overcharge, leading to damage.

Here are the different scenarios that need to watch out:

• If batteries consistently read above 14.4 volts (for a 12V system), this may indicate overcharging.
• On the other hand, a malfunctioning controller may not charge the batteries enough.
• Low battery voltage during peak sunlight hours could suggest the controller isn’t working properly.
• Frequent disconnections or erratic charging behavior can point to incorrect controller settings.
• If the solar panels produce more current than the charge controller can handle, the controller may shut down or fail.

Final Remarks

By now, you’ve seen that solar panel systems, like any technology, can face a variety of issues.

But most of these problems are easy to prevent or fix with a little attention.

The key is regular maintenance and inspections. It’s something I do myself, and it makes a big difference in keeping the system running efficiently.

Remember: Small steps today can prevent bigger (and more expensive) problems tomorrow. So, take a little time to care for your solar system, and it’ll take care of you for years to come!

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