8 Common solar panel issues and how to fix them

Key Takeaways

• Shading, faulty inverters, and weather damage can reduce solar power output, so check for obstacles, inverter errors, and panel defects.

• Sudden drops in energy production may signal a system issue requiring professional inspection.

• Compare current solar output to historical data to see if you should call a professional for analysis and repair.

Solar systems pump out energy from the sun when solar panels work correctly, but what about when things go south? Solar panel issues range from seeing a drop in power output to storage batteries not holding their rated capacity. Read on to learn about what to do if you run into different issues.

Solar panel issue #1: Not producing enough power

Are your solar panels not delivering the power you expected? It’s frustrating considering what you probably paid for installation. Shade from nearby trees, faulty inverters, damage from harsh weather, unexpected cloudy seasons, and awkward roof angles can all reduce your expected energy production, though there are often solutions.

What to do

Here’s what to do next:

• Check for new obstacles: Has a neighbor's tree grown taller or has a new structure been built nearby? Even partial shading can impact your energy production.

• Check the inverter: Look for error codes or warning lights that might indicate your inverter isn’t functioning properly. Remember, inverters typically last 10 or 15 years while panels last at least double that.

• Inspect the panels: You might spot visual defects like micro-cracks, snail trails (discoloration appearing as faint lines), or hot spots. These imperfections can may require a panel to be replaced if the issue is bad enough.

Keep in mind that seasonal changes naturally affect your solar output, but if you notice a sudden drop that doesn't align with weather patterns, that's a red flag.

To determine if your concerns are justified, compare your current production levels against your system's historical performance data or industry benchmarks for your region.

If there’s a big difference, you'll likely need to contact a solar professional for a thorough diagnosis and repair.

Solar panel issue #2: Covered in dirt or debris

You invested thousands to have clean energy, but now dust, pollen, bird droppings, and leaves block your savings. The worst part? You might not even notice a drop in performance until your electric bill spikes. What should be generating power is now just collecting grime. You definitely want to clean off dust and dirt to restore the energy flow.

What to do

Clean your panels with soft brushes and a solution of mild detergent and water during cooler parts of the day. Early morning or late afternoon work best. Avoid any abrasive materials or harsh cleaning chemicals that could scratch or damage the panels.

You should also inspect nearby trees every season. Consider trimming any overhanging branches that drop debris on your panels.

If you can’t physically reach the panels or get on your roof, schedule cleanings with a company at least twice a year.

Solar panel issue #3: Inverter malfunction

Whether you use string inverters, microinverters, power optimizers, or hybrid inverters, these components usually have shorter lifespans than the panels themselves. They can also malfunction before their expected lifetime is up, too. 

You might not have a visible problem, just mysteriously reduced output or complete system shutdown. Meanwhile, your panels sit there collecting sunshine that's going to waste. You might have to pay full electricity rates while waiting days or weeks for repairs.

What to do

Here’s how to troubleshoot inverter issues:

• Watch for warning signs: Note error codes, unusual noises, blank displays, reduced output, or overheating. When troubleshooting, first try restarting your inverter after a 5-minute power-down.

• Check connections: Check DC connections, verify grid stability, and guarantee proper airflow around the unit.

• Get professional help: For persistent issues, you'll need professional help to replace components, analyze grid faults, or reconfigure software.

To prevent future problems, get annual inspections and regularly update your system’s firmware.

Solar panel issue #4: Unexpectedly high electric bills

Shouldn’t your electric bill go down after you install solar, not up? If your system isn’t working properly, your bill might jump up suddenly. You invested in solar to reduce energy costs, so something’s wrong. 

Environmental changes like unusual weather patterns, new tree growth, or construction that creates shading can reduce your system’s capacity. Your household energy consumption may have increased beyond what your system was designed to handle, too. And in rare situations, components like panels or inverters can simply malfunction.

What to do

You should first verify if your system design matches your current energy needs. If you recently got an electric vehicle or added more energy-hogging appliances, your system might not be adequate anymore. Beyond that, consider the following:

• Understand your billing cycle and net metering: Take time to examine your billing cycle carefully. Many utility companies provide an annual true-up bill that might initially appear higher until your solar credits properly accumulate throughout the year.

• Monitor performance: Monitor your system's performance metrics regularly through an app or portal, and if you notice output has dropped considerably, consider scheduling a professional maintenance check.

• Consider usage times: Try adjusting your usage patterns to align with peak production hours when your panels generate the most electricity. You can heat or cool your home during the day to use less electricity from the grid at night, for example.

Solar panel issue #5: Loose or damaged wiring

Discovering loose or damaged wiring in your solar system can be alarming. You might worry about creating a fire hazard or the system failing if you find exposed or deteriorating connections. Plus, these issues often hide behind panels where you can't easily spot them. 

Wires shouldn’t touch the roof when properly installed, but thermal expansion and critters under your panels can cause issues over time. If you spot frayed cables or discolored connection points you're likely dealing with compromised wiring.

What to do

Here are steps you can take to solve some issues:

• Watch for signs: Monitor for unexplained production drops, inverter error codes, visible wire damage, burning smells, or overheating components.

• Tighten connections you can access: For immediate fixes, power down your system before securing loose connections with proper torque tools or replacing damaged cables. 

• Call a professional: Don't hesitate to call professionals for recurring issues, severe damage, or complex repairs.

• Invest in prevention: Schedule annual inspections, use protective coverings like weather-resistant conduits, and install monitoring systems to detect issues early.

While you can tighten connections using insulated tools and replace visibly damaged sections if you have electrical experience, remember that your safety comes first. Don't tackle repairs beyond your expertise.

Solar panel issue #6: Battery not charging properly

Battery charging issues can be really frustrating. You paid thousands for energy storage, but now it's not holding a charge when you need it most. And even on sunny days, the capacity remains low, leaving you vulnerable during power outages. Now, instead of providing energy independence, the battery is just an expensive box on your wall.

Battery charging problems can have many origins:

• Technical faults in charge controllers prevent proper voltage regulation

• Inverter monitoring issues causing incorrect readings or inefficient operation

• Insufficient capacity from undersized panels or improper system configuration

• Hardware problems like damaged diodes or faulty connections

What to do

You can diagnose the problem yourself by checking the status lights on your charge controller (which should show normal operation). You can also use a multimeter to test the voltage at key points and check the battery terminals for corrosion or buildup.

Most charging issues require either replacing faulty components or having a professional reconfigure your system. Even a battery that won’t charge can pose a risk of electric shock, so don’t do any DIY work you aren’t comfortable with.

Solar panel issue #7: Cracked or broken panels

Hairline fractures and shattered glass reduce your output. But they can also lead to water infiltration and electrical issues over time. Hailstorms, debris like falling branches, or extreme temperature fluctuations can crack the glass surfaces over time. 

Thermal stress from rapid heating and cooling cycles or manufacturing defects might create micro-fractures that worsen over the years. Figuring out whether the manufacturer, installer, or insurance is responsible is another headache. 

What to do

Solar panels can continue to function for a while with cracks and even broken glass, but you’ll want to have a professional replace the panel as soon as possible. Water could enter the crack and cause more issues with the system.

That said, if you built your own DIY solar setup, you might look into sealing the glass with a clear polyurethane. Of course, test the panel first to make sure it still functions well enough to be worth keeping.

Solar panel issue #8: Decreasing efficiency over time 

Solar panel efficiency naturally degrades over time. It’s just a fact of life. However, efficiency should only degrade by 0.5% to 1% per year. If you notice your system performs 5% worse than the year before, something fishy is going on.

What to do

Your first task is to figure out if efficiency loss is within the manufacturer's guidelines. Consult your solar panel manufacturer’s ownership documentation and warranty. If you’ve had the panels for 10 years and have seen a 5% drop in efficiency over that time, your panels are functioning as expected.

Now see if the efficiency loss follows a steady decrease. A quick drop in output can be caused by other things we’ve covered above, like debris or damage.

If you see a steady decrease in efficiency above the manufacturer's tolerances, it’s time to contact the manufacturer. Most solar panel performance warranties are effective for 20 to 30 years, so the manufacturer may cover the replacement panel. That said, you could still have to cover shipping and installation costs.

Bottom line: Solar panel issues have solutions

Solar panels do have issues, and going solar isn't for everyone. That said, many solar panel problems have straightforward solutions. Solar panels also don’t have any moving parts, so repairs tend to be few and far between with the right setup. If you’re thinking of going solar, plan some extra room in your budget for occasional issues so you aren’t taken by surprise.

FAQs about solar panel issues

Below are some frequently asked questions about issues with solar panels.

What is the biggest issue with solar panels?

The biggest issue with solar panels is the payoff isn’t worth the high initial cost for many homeowners. This depends on lots of factors like net metering availability, financing options, and your current energy bill. Research solar panels thoroughly to decide if they’re worth it.

Can a damaged solar panel be repaired?

Yes, some damaged solar panels can be repaired. You can fix minor cracks with laminating film or epoxy resin and then test with a multimeter after repairs. However, the repaired panel might not work very well or last as long as a new one.

What should I do if my solar panels are not working?

If your solar panels stop working, check your monitoring system, inspect for visual damage, verify circuit breaker connections, and check your inverter status. Look for shade issues or loose wiring before calling a professional.

What is a common defect on a solar panel?

Solar panel hot spots are defects that happen when localized areas overheat. This could be because of partial shading, cell mismatches, physical damage, poor connections, or bypass diode failures. These failure areas convert energy to heat instead of electricity, causing reduced output and even permanent damage.