Solar Panels Not Generating? Here's How to Diagnose It
If your solar panels suddenly stopped producing electricity, take a breath — in most cases the panels are fine and the problem is at the inverter or a tripped switch, not the roof. This page walks you through the most likely causes in order, the handful of checks you can safely do yourself, and exactly when to stop and call a registered electrician. For ongoing care see our solar panel maintenance guide, and if you suspect the inverter itself, our inverter comparison explains how they work.
Quick Answer
The most common reason solar panels stop generating is the inverter being off, in fault, or a tripped breaker or isolator. Check the inverter display first: if there is no light or a red light, look at the AC/DC isolators and the consumer-unit breaker, and confirm it is not simply night, low light, or a power cut before assuming a fault.
Last updated June 2026
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
Why are my solar panels not generating electricity?
There is rarely a single obvious culprit, so it helps to work through the possibilities from most to least likely. The good news is that the most common causes are reporting or switching issues, not failed panels. Here are the usual suspects, roughly in order of how often they turn out to be the problem.
1. Inverter is off, in fault, or a switch has tripped
This is by far the most common cause. The inverter is the brain of the system, and if it is off, showing a fault, or a breaker or isolator feeding it has tripped, generation stops even though the panels are perfectly healthy. Always check the inverter display, the AC and DC isolators, and the consumer-unit breaker first.
2. It is night or very low light
Solar systems produce little to nothing in darkness, heavy overcast, or at dawn and dusk. Before assuming a fault, confirm there is genuinely daylight on the panels. A reading of zero at night is completely normal.
3. A string MCB or fuse has tripped
A protective MCB or fuse on a panel string can trip, taking that string offline. You may notice output that is roughly half or a third of normal rather than a full zero. This usually needs an electrician to investigate safely.
4. A grid fault or power cut
By design, a standard grid-tie inverter shuts down during a power cut so it cannot feed electricity back into a dead network. Unless you have a battery or backup-capable inverter, no grid usually means no solar generation. Check whether your whole house, or the wider area, has power.
5. An inverter fault code or isolation fault
Inverters self-protect and will display a fault code or warning light for issues such as an isolation (earth) fault. Note the code or message shown, but do not open the unit — this is diagnostic information for your installer or electrician.
6. A tripped RCD
A residual current device (RCD) in your consumer unit may trip and cut power to the solar circuit. You can look to see if an RCD has tripped, but repeated tripping points to an underlying electrical fault that needs a professional.
7. A monitoring app glitch
Sometimes the panels and inverter are working fine and only the reporting is down — a dropped Wi-Fi connection, an app outage, or a logged-out account. If your app shows zero but the inverter display shows normal output, the issue is reporting, not generation.
8. Shading or soiling
New tree growth, a satellite dish, scaffolding, heavy moss, bird droppings, or thick dirt can reduce output. This usually causes a gradual drop rather than a sudden zero, but heavy shading on a string can have an outsized effect.
9. A failed panel, string, or chewed cabling
Less commonly, a panel or string fails, or rodents and martens chew through cabling under the array. These need a qualified professional to diagnose and repair safely.
What can I safely check myself?
There are a few simple, no-risk checks you can do without touching any wiring. These resolve a surprising number of cases on their own, and even when they don't, the information helps your installer or electrician fix things faster. Work through them in order.
Step 1 — Read the inverter
Look at the inverter's status light and display. A green light usually means normal operation. A red or orange light, a blank screen, or a fault code points to where the problem is. Write down any code or message exactly as shown.
Step 2 — Check the isolators are ON
Your system has AC and DC isolator switches near the inverter. Confirm they are in the ON position. They can be knocked off accidentally. Just check the switch position — never open the isolator or inverter housing.
Step 3 — Check the breaker
Look in your consumer unit (fuse board) for the solar circuit breaker or RCD. If one has tripped, you can switch it back on once. If it trips again immediately, leave it off and call an electrician — that is a sign of a real fault.
Step 4 — Confirm it is daylight
Make sure it is genuinely daylight and not a dim, overcast early morning. Zero output at night or near dusk is normal and not a fault. Compare what you see now to a bright midday.
Step 5 — Check the app
Open your monitoring app and compare it to the inverter display. If the inverter shows output but the app shows zero, the panels are working and only the reporting (often Wi-Fi) is down. Try reconnecting the inverter to your home network.
Step 6 — Rule out a power cut
Check that the rest of your house has power and look up whether there is an outage in your area. A standard grid-tie inverter will not generate during a power cut, so this alone can explain zero output.
When should I call an installer or electrician?
Safety: this part is genuinely dangerous
Solar DC wiring and inverters carry lethal voltage and stay live whenever there is daylight on the panels — there is no "off switch" for the sun. You may check app, breaker, and display-level things, but you must never open an inverter or touch the DC wiring. For anything electrical, use a RECI / Safe Electric registered electrician in Ireland, or the original SEAI-registered installer while the system is under warranty.
Stop your own checks and bring in a professional if any of the following apply:
- The inverter shows a fault code, an isolation fault, or a persistent red light.
- A breaker or RCD trips again as soon as you reset it.
- Output is partial (for example roughly half), suggesting a string MCB, fuse, or panel issue.
- You see scorching, melting, burning smells, buzzing, water ingress, or chewed cabling.
- Everything looks fine on your side but generation is still zero in full daylight.
Who to call, and in what order
If your system is still under warranty, contact the original SEAI-registered installer first — opening the equipment yourself or using an unauthorised contractor can void cover. If the installer is unavailable or the system is out of warranty, use a RECI / Safe Electric registered electrician. Always confirm registration before any work on the AC or DC side of a solar system.
The Irish context: ESB Networks, NC6 & power cuts
A few things specific to Ireland are worth understanding when your system goes quiet, because some "faults" are actually normal, designed behaviour.
No generation during a power cut is normal
In Ireland, grid-tie solar is connected under the ESB Networks NC6 process. By design these systems will not run your loads during a power cut unless you have a battery or a backup-capable inverter. So during an outage, zero solar output is expected, not a fault.
Grid voltage and the inverter shutting down
Inverters monitor the grid and can pause if the local network voltage drifts outside permitted limits. This is a protective feature. If it happens repeatedly, your installer can raise it with ESB Networks, but it is not something a homeowner adjusts.
Smart meters, export and your supplier
Under the National Smart Metering Programme, an NSMP smart meter records what you export. If generation looks fine but you are not being paid, that is usually a metering or supplier-side issue rather than a panel fault. Our microgeneration guide explains how export payments and the Clean Export Guarantee (CEG) work in Ireland.
Solar Panels Not Generating FAQ
Why have my solar panels suddenly stopped generating?
The most common cause is the inverter being off, in fault, or a tripped breaker or isolator, rather than a panel failure. Check the inverter display first. If there is no light or a red light, check the AC and DC isolators are on and look at the solar breaker in your consumer unit. Also rule out night-time, very low light, or a power cut before assuming a fault.
Do solar panels work during a power cut in Ireland?
Usually not. In Ireland, standard grid-tie systems are connected under ESB Networks NC6 and shut down during a power cut by design, so they cannot feed a dead network. Unless you have a battery or a backup-capable inverter, zero output during an outage is normal and expected, not a fault.
Can I fix my solar inverter myself?
No. Solar DC wiring and inverters carry lethal voltage and stay live whenever there is daylight, so you must never open an inverter or touch the DC wiring. You can safely check the display, isolator switch positions, the breaker, and the monitoring app. Anything beyond that needs a RECI / Safe Electric registered electrician or your original SEAI-registered installer.
My monitoring app shows zero but is the system actually broken?
Not necessarily. Sometimes only the reporting is down, often a dropped Wi-Fi connection or an app outage, while the panels and inverter keep working. Compare the app to the inverter display itself. If the inverter shows normal output but the app shows zero, the issue is monitoring, not generation, and reconnecting the inverter to your home network usually fixes it.
Who should I call if my solar panels are not producing power?
If the system is under warranty, contact the original SEAI-registered installer first, because opening equipment yourself or using an unauthorised contractor can void cover. If the installer is unavailable or the system is out of warranty, use a RECI / Safe Electric registered electrician. Always confirm registration before any work on the AC or DC side of the system.
Related Guides
Solar Troubleshooting
Diagnose common solar faults: generation, inverter, battery, export.
Solar Inverter Fault
Red light or fault icon? What it means and what to check.
Solar Generation Low
Producing less than expected? Season, shading, soiling and more.
Maintenance Guide
Cleaning, monitoring, warranties, and lifespan.
Sources
- ESB Networks — Connecting a Micro-Generator (NC6)
- Safe Electric — Registered Electrical Contractors (RECI)
- SEAI — Solar Electricity Grant & Registered Installers
Last updated 11 June 2026.
John Rooney is the founder of Solar Info and has been covering the Irish solar energy market since 2023. He fact-checks all content against official SEAI data and maintains relationships with SEAI-registered installers across Ireland.
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