Most homeowners never notice their solar system is underperforming until the utility bill arrives. By then, the problem has often been going on for weeks or months, quietly costing money every day. According to the 2025 Global Solar Report by Raptor Maps, equipment-driven underperformance has increased 214% since 2019, resulting in an estimated $10 billion in lost energy value worldwide in 2024 alone. That figure is not a commercial-scale anomaly. It shows up on residential rooftops too, panel by panel and kilowatt-hour by kilowatt-hour.
The good news is that most solar panel problems are diagnosable and fixable when caught early. The key is knowing what signs to watch for, understanding which issues require a professional, and acting before a minor fault becomes a full system failure.
This guide covers the most common reasons a solar system stops producing, what you can check yourself, when to call for solar panel repairs, and how to protect your warranty in the process.
Your Monitoring App Is the First Place to Look
Every modern solar installation comes with a monitoring platform, most commonly SolarEdge, Enphase Enlighten, or a similar app. These tools show real-time and historical production data, and they are the fastest way to identify whether your system is actually underperforming or simply responding to a cloudy stretch of weather.
Log into your monitoring portal and compare current production to the same month in a prior year. A single low-output day is rarely a cause for concern, but a consistent week-over-week decline that does not match weather patterns is a signal worth taking seriously. If your system has panel-level monitoring, look for individual panels showing zero or near-zero output. That localized drop often points to a failed microinverter, a shading issue, or physical damage on a specific module rather than a system-wide problem.
Before calling for service, screenshot your monitoring data. Many warranty claims require documented evidence of performance degradation over time, and having that data on hand makes the process significantly faster.
The Five Most Common Causes of Solar Panel Problems
Not every drop in output means your panels are broken. But several issues show up repeatedly across residential solar systems, and knowing them helps you describe the problem accurately when you call for service.
Inverter faults
The inverter converts the DC electricity your panels generate into the AC power your home uses. When it fails, your system can stop producing entirely. Research from the National Renewable Energy Laboratory (NREL) found that around 50% of all solar PV system downtime is caused by inverter failures. Common warning signs include error codes on the inverter display, the unit feeling hot to the touch, frequent automatic shutdowns, and a sudden drop to zero production on an otherwise sunny day. String inverters typically last 10 to 15 years, which means systems installed in the mid-2010s may be approaching the end of their inverter lifespan now.
Wiring and connection issues
Loose, corroded, or damaged wiring is one of the more serious faults a system can develop because it does not just reduce output; it creates a fire hazard. Rodents are a frequent culprit, particularly in areas with heavy wildlife activity. Squirrels and birds can chew through wiring beneath panels, causing intermittent faults that are difficult to diagnose without a professional inspection. Never attempt to investigate or repair wiring yourself. This is work for a licensed solar technician with proper safety equipment.
Physical damage to panels
Cracked glass, delamination (where the panel layers begin to separate), and hot spots caused by cell damage can all reduce output. Some physical damage is visible from the ground with binoculars. Hot spots in particular are invisible to the naked eye but detectable through thermal imaging, a diagnostic tool that professional solar technicians use to locate failing cells without disassembling the system. Small cracks and chips on the glass surface may be repairable, but panels with internal cell damage typically require replacement.
Soiling and debris buildup
Dirt, dust, bird droppings, and pollen accumulation can reduce solar output by 5 to 25% depending on severity. In the Central Valley, where agricultural dust and dry conditions are a year-round reality, this is a particularly common performance drain. If your monitoring data shows a gradual, steady decline rather than a sudden drop, soiling is often the first thing to rule out. Professional cleaning typically resolves this quickly and at low cost.
Monitoring and communication failures
According to SolarReviews‘ 2025 industry survey, 52% of solar installers report that monitoring, communication, and internet connection problems are the most common after-installation issues they handle. If your app shows no data but your system appears to be running, the system itself may be fine. A Wi-Fi dropout or communication device failure can make a functioning system look like a dead one. This is worth ruling out before assuming a hardware problem.
What You Can Check Yourself vs. What Requires a Professional
There is a clear line between homeowner troubleshooting and professional solar panel repairs, and staying on the right side of it protects both your safety and your warranty.
Things you can check yourself:
- Your monitoring app for production data and error alerts
- The inverter display for visible error codes
- Whether the inverter’s Wi-Fi or communication device is connected
- Visible debris or shading on panels (from the ground using binoculars)
- Whether your main electrical panel has tripped a breaker related to the solar system
Things that require a licensed solar technician:
- Any wiring inspection or repair
- Inverter diagnostics, repair, or replacement
- Physical inspection of panels on the roof
- Thermal imaging to detect hot spots or cell damage
- Warranty claims that require documented professional assessment
Attempting to repair electrical components yourself not only risks personal injury; it can void your equipment and workmanship warranties. Most manufacturers explicitly state that DIY repairs or unauthorized modifications will cancel coverage.
Understanding Your Warranty Before You Call for Repairs
Solar systems come with several overlapping warranties, and knowing which one applies to your problem determines whether a repair is free or out of pocket.
Panel product warranties typically cover defects in materials and workmanship for 10 to 25 years depending on the manufacturer. Performance warranties are separate and guarantee that panels will produce at least 80% of their original output after 25 years, with a degradation rate of no more than 0.5% to 1% per year considered normal. If your system is declining faster than that, a performance warranty claim may apply.
Inverter warranties vary significantly by technology. According to EnergySage, string inverters typically carry 10 to 12 years of warranty coverage, while microinverters from brands like Enphase are often covered for 25 years. One detail most homeowners miss: manufacturer warranties generally cover parts but not the labor and truck roll costs required to perform the repair. Those costs are usually the homeowner’s responsibility unless an extended service plan was purchased at installation.
Workmanship warranties come from your installer and cover the quality of the installation itself. These typically run 5 to 10 years. If a wiring fault or mounting failure is traced back to a problem with the original installation, this is the warranty that applies.
If your original installer is no longer in business, your panel and inverter manufacturer warranties remain valid. You will need to work with a licensed solar company to coordinate the warranty claim and perform any covered repair or replacement.
Frequently Asked Questions About Solar Panel Repairs
How do I know if my solar panels are not working properly?
The most reliable way is to check your monitoring app and compare current production to the same period in prior years. A drop of more than 15% that is not explained by weather or seasonal changes warrants a professional inspection. A higher-than-expected utility bill is often the first sign homeowners notice.
How much do solar panel repairs typically cost?
Costs vary by the type of repair needed. Professional cleaning runs $150 to $400. Inverter repairs range from $500 to $3,000 depending on the type of inverter and the extent of the fault. Panel replacement costs depend on the model, but physically damaged panels that fall outside warranty coverage can run $200 to $700 per panel plus labor. Many repairs are covered partially or fully under manufacturer warranties, so checking warranty status before paying out of pocket is always the right first step.
Will my solar panels work during a power outage?
Standard grid-tied solar systems without battery storage shut down automatically during a grid outage. This is a safety feature required by law, designed to prevent backfeed from energizing utility lines while crews work on them. If you want backup power during an outage, a battery storage system paired with your solar installation is what makes that possible.
Can I get solar panel repairs done if my original installer went out of business?
Yes. Your panel and inverter manufacturer warranties remain in force regardless of whether your original installer is still operating. A licensed solar contractor can inspect your system, identify the issue, and work with the manufacturer to process a covered repair or replacement. What you lose when an installer closes is access to the workmanship warranty, which is tied to that company specifically.
How often should I have my solar system professionally inspected?
Most solar professionals recommend a professional inspection every one to two years, in addition to routine monitoring through your app. An annual inspection covers wiring integrity, inverter function, mounting hardware, and panel condition, catching issues before they compound into larger, more expensive problems.
A System That Stopped Producing Is a Problem You Can Solve Today
Solar panel problems are rarely catastrophic when caught early. The homeowners who see the biggest losses are typically the ones who did not notice the drop in production for months, or who waited too long to call because they were unsure whether the issue was real. If your monitoring data looks off, your bill is higher than it should be, or your inverter is throwing error codes, those are not signs to wait on.
Pacific Solar provides solar repair services for systems across the Central Valley, including diagnostics, inverter service, wiring inspections, and warranty claim support. If your system is not performing the way it should, the team at Pacific Solar can assess what is wrong and get it back to full production. Contact Pacific Solar today to schedule a diagnostic inspection.