Solar Panels Not Producing Power? Causes and What to Check
If your solar system seems to be making less power than it used to, or nothing at all, the cause is usually one of a short list. Some you can check in five minutes. Others need a technician.
Check these first (safe, no tools)
- Look at the inverter. A solid green light normally means it is producing. Red, flashing or blank means a fault or no power. Write down any error code or take a photo.
- Check your monitoring app. If it says offline, the panels may be fine and only the internet link is down. See monitoring offline.
- Compare to last year. Open the same month from last year. A big drop on a similarly sunny stretch is a real signal.
- Look for new shade. Tree growth, a new building or a satellite dish can shade part of an array.
- Look at your bill. If your bill rose with no change in how you use power, your system may be making less than you think.
Do not open the inverter, panel boxes or wiring. Switches on the outside are fine to read, but leave the rest to a licensed technician.
Common causes
- Inverter fault or failure. The most common cause. String inverters often fail in the 10 to 15 year range, and heat shortens that.
- One failed unit. On systems with microinverters or optimizers, one bad unit cuts output without shutting the system down, so it can go unnoticed for months.
- Tripped breaker or rapid shutdown device. Power can be lost to the whole array from one switch.
- Ground fault or wiring damage. Often shows as an isolation or ground-fault error on the inverter.
- Dirty or shaded panels. Dust, bird droppings and shade lower output but rarely stop it.
- Monitoring only. The system works but the data link dropped.
Why a drop can go unnoticed
On a sunny day a partly failed system still looks busy. That is why a drop is easy to miss: the roof is making power, just less than it should. The most reliable check is comparing expected output with what your actual bill shows over a full year, not looking at one afternoon.
What we do
We review your photos, inverter model and error codes, and your utility bill, and then tell you plainly what we think is wrong, whether it is covered by a warranty, and what a fix involves. We work on any brand and any installer, including companies that have closed. The first evaluation is free and has no obligation.
Get a free evaluation
Tell us about your system and we will start with your photos and your bill. Where it makes sense, we will schedule a technician visit or a guided video evaluation. No obligation.
Book a Free Evaluation → Call (619) 777-6527Common questions
Check the inverter light and your monitoring app, and compare this month to the same month last year. A system can look fine on a sunny day and still be making much less than it should.
Yes. An inverter fault, one failed microinverter or a tripped switch may not trigger a visible alarm, so a drop can go unnoticed for months.
It depends on the part and who made it. Many inverters and panels carry long manufacturer warranties even if the installer has closed. We check what applies to your equipment.