Most solar system failures show up first as a number: a production reading that is lower than it should be, or a monitoring alert that appears one morning and does not go away. By the time a homeowner notices their PG&E bill has crept back up, the system may have been underperforming for weeks.
The Central Valley’s solar environment is demanding. Summer temperatures in Fresno regularly exceed 105 degrees Fahrenheit, agricultural dust accumulates on panels faster than in most other markets, and systems installed in the mid-2010s are now reaching the age where inverters commonly fail. Knowing what to look for, what each type of repair costs, and who to call makes the difference between a fast fix and months of lost savings.
The Most Common Reasons Solar Systems Fail
Inverter Failure
The inverter converts the DC electricity your panels generate into the AC power your home uses. It is also the component most likely to fail. A study of 100,000 PV systems by the National Renewable Energy Laboratory found that inverters are the most frequently failing component, accounting for 4 to 6 percent of system failures, and a kWh Analytics analysis found that roughly 80 percent of solar array downtime is inverter-related.
String inverters typically last 10 to 15 years. Systems installed in Fresno and the Central Valley between 2010 and 2015 are now at or approaching that threshold, which means inverter replacement is an increasingly common repair for the region’s existing solar stock. Microinverters, mounted on each individual panel, tend to have longer warranties but can still fail and are more complex to diagnose when they do.
Warning signs of inverter trouble: error codes or warning lights on the inverter display, the unit running noticeably hot to the touch, the system going offline on sunny days, or a sudden drop to zero production visible in your monitoring app.
Wiring and Connector Faults
Loose, corroded, or damaged wiring reduces output and, in serious cases, creates a fire hazard. NREL’s field reliability research identifies connector and wiring failures as a significant source of production loss and safety concerns, frequently linked to undersized components, improper connections at installation, or deterioration over time from heat cycling and moisture.
In the Central Valley, rodent activity is an additional risk factor. Squirrels and other small animals nest under rooftop panels and chew through wiring insulation, a failure mode that does not always trigger an obvious alert but steadily degrades system performance. A system producing 10 to 15 percent below expected output with no inverter errors is often showing a wiring fault rather than a panel problem.
Panel Damage
Physical panel failures are relatively rare compared to inverter and wiring issues. NREL’s analysis of over 50,000 systems found a median panel failure rate of approximately 5 panels per 10,000 annually. When panels do fail, the most common causes are cell delamination from heat and moisture cycling, micro-cracks from physical impact or thermal stress, and junction box failure at the electrical connection point on the back of the panel.
Visible signs of panel damage include discoloration, scorch marks (hotspots), cracked glass, or sections of a panel that appear darker or lighter than adjacent cells. A panel with a hotspot or crack may continue producing power at reduced output, which is why monitoring data often catches these problems before a visual inspection does.
Soiling and Shading
Not every production drop is a mechanical failure. In the Central Valley, agricultural dust, wildfire ash, and Tule fog residue accumulate on panels faster than in most other California markets. A system with heavily soiled panels can lose 15 to 25 percent of its output. Before calling for a repair, check whether the production drop aligns with recent weather events or a period without rain, and consider whether a professional cleaning might resolve the issue.
Similarly, new shading from tree growth, a neighbor’s structure, or a rooftop addition that was not present at installation time can cause production losses that look like equipment failures in monitoring data. Shading that affects only certain panels or certain hours of the day is a diagnostic clue that the issue is environmental rather than mechanical.
What Solar Repairs Cost in Fresno
Repair costs vary depending on the type of failure, the age and brand of the equipment, and whether the repair falls within warranty coverage. The figures below reflect typical out-of-pocket costs for Central Valley homeowners when repairs are not covered under warranty.
| Repair Type | Typical Cost Range | Notes |
| System diagnostic / inspection | $150 – $300 | Often waived if repair is booked |
| Inverter repair | $500 – $1,500 | Depends on fault complexity |
| Inverter replacement (string) | $1,500 – $2,500 | Parts + labor; brand-dependent |
| Inverter replacement (micro) | $300 – $600 per unit | Individual microinverter swap |
| Wiring / connector repair | $200 – $600 | Most residential fixes |
| Panel replacement | $400 – $800 per panel | Higher for discontinued models |
| Professional cleaning | $150 – $400 | Recommended annually in CV |
Note: Many repairs are fully or partially covered under manufacturer warranties or installer workmanship warranties. Always check your warranty status before paying out of pocket. SunMade can assist with warranty claims regardless of who performed the original installation.
How to Tell If Your System Has a Problem
The fastest way to catch a solar system issue early is consistent monitoring through your inverter’s app or web portal. Most modern inverters, including systems from Enphase, SolarEdge, and SMA, provide daily production data that makes it easy to spot anomalies. Here is what to look for:
- Production significantly below the same period last year, adjusted for weather and season
- A panel or string showing zero or near-zero production on a clear day
- Error codes or warning alerts from your inverter’s monitoring system
- Your PG&E bill increasing despite consistent sunlight and usage
- The inverter display showing a fault code, blinking lights, or no display at all
- Visible physical damage: cracked glass, scorch marks, or discoloration on any panel
If your system does not have active monitoring, or if you are not sure how to read the data, a professional diagnostic visit is the appropriate starting point. A licensed technician can assess the full system, identify the fault, and give you a clear picture of what the repair involves before any work begins.
What You Should Not Do When Your System Fails
Solar systems operate at high-voltage DC power levels that are significantly more dangerous than standard household electrical systems. Before attempting any self-diagnosis beyond checking your monitoring app, be aware of what creates real risk:
- Do not walk on or near panels. Even light pressure can cause hidden micro-cracks that void manufacturer warranties and degrade output.
- Do not touch wiring, connectors, or junction boxes. DC power from a solar array does not shut off when the inverter is disconnected, and shock from an unprotected connection can be fatal.
- Do not pressure wash panels. High-pressure water can break seals, strip anti-reflective coatings, and force water into connections, converting a performance issue into a component failure.
- Do not ignore inverter warning codes. A fault that is flagged and addressed quickly is usually a minor repair. The same fault left unattended for weeks or months can cause cascading damage to other components.
Does Your Original Installer Have to Do the Repair?
No. Any licensed solar contractor can service your system, file warranty claims on your behalf, and perform repairs, regardless of who installed it originally. Manufacturer warranties on panels and inverters are tied to the equipment, not to the installing company. If your original installer has gone out of business, moved out of the region, or simply stopped returning your calls, another licensed contractor can step in.
What you lose when an installer is no longer available is access to the workmanship warranty, which is specific to that company. Manufacturer equipment warranties remain valid and can be processed by any certified service provider.
SunMade services and repairs solar systems across Fresno and the Central Valley regardless of who installed them. That includes navigating manufacturer warranty claims for customers whose original installer is no longer operating.
Frequently Asked Questions
How do I know if my solar system needs a repair or just a cleaning?
Soiling-related production drops typically appear gradually over weeks and worsen after dry periods or dusty conditions. A repair issue, particularly an inverter fault, usually shows up as a sudden drop on a specific day, a flat-line reading from one panel or string, or an error code. If cleaning does not restore production within a few days of clear weather after a thorough clean, the issue is likely mechanical rather than soiling.
My solar monitoring app shows one panel not producing. What does that mean?
A single panel showing zero or near-zero output on a clear day typically points to one of three causes: a failed microinverter (if your system uses them), a shading obstruction that is affecting that location only, or a failed panel. A licensed technician can isolate the cause with electrical testing in a single visit.
Can I file a warranty claim without my original installer?
Yes. Panel and inverter manufacturer warranties are tied to the equipment and remain valid regardless of who installed it or whether that company still exists. A licensed solar contractor can inspect your system, document the fault, and submit the warranty claim to the manufacturer on your behalf. What requires your original installer specifically is the workmanship warranty, which does not transfer.
How long does a typical solar repair take in Fresno?
A diagnostic visit typically takes one to two hours. Simple repairs such as a wiring connection, a cleaning, or a single microinverter swap are often completed in the same visit. Inverter replacements that require a specific unit to be ordered generally take three to seven business days from diagnosis to completion, depending on parts availability.
Should I repair my old inverter or replace it?
If your string inverter is approaching or past the 12-to-15-year mark, replacement is usually the better investment. Repairing an aging inverter often addresses one symptom while leaving other age-related components intact. Replacing the inverter also provides an opportunity to upgrade to a model with better monitoring, compatibility with modern battery storage, or improved efficiency ratings.
SunMade Repairs What Others Installed
SunMade Energy provides solar repair and diagnostic services throughout Fresno, Clovis, and the broader Central Valley. Our licensed team handles inverter failures, wiring faults, panel replacements, and system troubleshooting, whether or not SunMade performed the original installation.
If your system is underperforming, showing errors, or has gone offline, the fastest next step is a professional diagnostic. We identify the fault, give you a clear explanation of what the repair involves, and provide a cost estimate before any work begins. Many repairs are covered under existing warranties, and we handle that process on your behalf.
