No. A standard grid-tied solar system in Ireland stops producing the moment the grid goes down, even in bright sunshine. That is not a fault and it is not your installer cutting corners. Every micro-generator connected to the ESB Networks system has to comply with IS EN 50549-1 with current Irish settings, and that standard requires the inverter to disconnect when it loses the mains. The reason is straightforward: a solar system feeding a dead line could kill the network technician repairing it. Getting power during an outage is possible, and ESB Networks sets out how, but it needs specific hardware and a Registered Electrical Contractor to fit it. A battery on its own does not do it.
- Panels alone give you nothing in a power cut. The inverter shuts down within milliseconds of losing the grid
- A battery alone does not fix it either. Most are wired to charge and discharge alongside the grid, not replace it
- ESB Networks explicitly allows solar, batteries and EVs to be used as standby generation, but only in island mode with a changeover switch that breaks parallel with the mains
- That work must be designed, installed and tested by a Registered Electrical Contractor under Safe Electric
- There is no SEAI grant for a battery or for backup hardware. The Solar Electricity Grant covers PV and caps at €1,800 in 2026
Why Your System Shuts Down When the Grid Does
A grid-tied solar inverter does not generate 230V out of nothing. It synchronises to the voltage and frequency it senses on the ESB Networks supply and pushes power out in step with it. Take the grid away and the reference signal disappears with it.
The inverter could, in principle, carry on and energise your house anyway. It is specifically built not to. ESB Networks requires that the generator (inverter) must comply with IS EN 50549-1 with current Irish settings, and a type test certificate proving that compliance has to accompany your NC6 notification form. Loss-of-mains protection is part of what that standard covers. When the grid voltage vanishes, the inverter disconnects, typically in a fraction of a second.
The safety case behind it is not theoretical. During a storm, ESB Networks crews work on low-voltage lines they have isolated and expect to be dead. If a house on that line were quietly back-feeding solar into the network, the line would be live and there would be nothing on the pole to tell the technician. The industry term for that hazard is islanding, and the protection against it is anti-islanding.
Why a Battery on Its Own Is Not the Answer
This is the part that catches people out, usually after they have paid for the battery. A home battery in a standard Irish installation is there to shift energy through time, not to keep you running when the network fails. It soaks up midday surplus and gives it back in the evening, cutting what you import at peak rates.
In a power cut, that battery can be sitting at 90% charge and still give you nothing. It discharges through the same inverter, which has just disconnected for the reasons above. Unless the system was specified with backup in mind, a full battery and an empty one behave identically during an outage.
Two things have to be true before stored energy reaches your sockets:
- The inverter must support island mode. Most quality hybrid inverters do. Standard string inverters generally do not, and no amount of extra battery capacity changes that
- There must be a way to physically break parallel with the grid. That is the changeover switch, and it is a separate piece of hardware
If you already have solar and are wondering which category your kit falls into, the inverter model number is the place to start. Our guide to solar inverters in Ireland covers the difference between string and hybrid units.
What ESB Networks Actually Permits
Backup is not a grey area or a workaround. ESB Networks addresses it directly, and the wording matters, so here it is close to verbatim.
Asked whether you can use solar PV, a battery or an EV as a standby generator, ESB Networks answers yes. These sources may be used in the event of a loss of mains electricity supply. In normal circumstances they run in parallel with the mains supply. However, if they are to be used as a source of standby generation, meaning island or off-grid mode, they need to be designed, installed and tested for correct operation by a Registered Electrical Contractor. An appropriate changeover switch to break parallel with the ESB Networks mains electricity supply, as per the National Wiring Rules for Electrical Installations, must be used.
Three things follow from that:
- It is permitted. You are not bending any rule by wanting backup power
- It is not a DIY job and not a job for a general handyman. The contractor has to be registered with Safe Electric, and the installation has to be tested, not just wired
- The changeover switch is mandatory, not optional. It is the thing that guarantees your island cannot back-feed a dead network
One further point worth knowing: ESB Networks states that standby generators cannot be used to sell electricity to the grid. Running in island mode and earning Clean Export Guarantee payments are two separate modes of operation. You are not exporting while you are islanded, which is the whole point.
The Two Routes to Backup Power
Once you accept that some extra hardware is needed, there are two realistic options, and they sit a long way apart on price.
Route 1: Changeover switch, no battery
The cheaper route. A changeover switch, sometimes called a transfer or islanding switch, is fitted so you can disconnect the house from the grid. The inverter then detects it is isolated and runs in island mode, feeding a defined backup circuit directly from the panels.
The honest limitation is daylight. With no battery in the system, you have exactly as much power as the roof is producing at that moment. On a bright afternoon in May that might be several kilowatts. At 9pm in January it is zero. A storm outage that starts on a wet winter evening is precisely when this route delivers least.
Most versions are also manually operated. You go to the switch, throw it, and throw it back when supply returns. Irish installers publishing prices put this work at roughly €800 to €1,500 installed, depending on how the backup circuit is configured. Treat that as a planning figure and get it quoted for your own house.
Route 2: Hybrid inverter plus battery
The full solution. A hybrid inverter with a battery and backup capability detects the outage, isolates from the grid automatically, and carries the backup circuit on stored energy plus whatever the panels are making. Better systems do this fast enough that the lights barely flicker.
What you gain over the switch-only route is time-of-day independence. The battery works at 3am in December just as well as at noon in June, which is the whole reason people want backup in the first place.
A 10 kWh battery costs €4,500 to €7,000 installed in Ireland. Add backup switching on top of that. The Tesla Powerwall 3 is the best-known example of a unit with whole-home backup and automatic switchover built in, at roughly €8,000 to €11,000 installed.
What a Backup Circuit Realistically Runs
Backup in an Irish home almost always means essential circuits, not the whole house. That is a deliberate design choice rather than a compromise. High-draw appliances would flatten a battery in under an hour and can exceed what the inverter can deliver at all.
A sensibly specified backup circuit typically carries:
- Lighting, which on LED draws very little
- Fridge and freezer, the loads with the most to lose in a long outage
- Broadband router and phone charging
- Heating controls, so an oil or gas boiler pump and thermostat keep working
- A handful of nominated sockets
What gets left off: electric showers, electric ovens, immersion heaters and tumble dryers. Each of those pulls in the region of 3 kW or more.
The arithmetic is reassuring once you scope it that way. Fridge, lights, router and heating controls together sit in the low hundreds of watts. A 10 kWh battery running a few hundred watts of essentials covers well over a day, and any daylight generation extends that further.
Why This Question Comes Up in Ireland
Irish homeowners ask about power cuts more than homeowners in most of Europe, and the reason is the weather.
Storm Éowyn hit on 24 January 2025 and took supply from 768,000 ESB Networks customers. ESB Networks called it by far the worst storm it has experienced, both in customers losing supply and in the scale of damage to the network. Restoration ran for over a week in the worst-hit areas. Anyone who sat through that with panels on the roof and no power in the house has a fair question about what those panels were doing.
The answer is that they were doing exactly what the connection rules require. Whether that is acceptable depends on where you live. In a suburban estate on an underground network, outages are rare and short, and a changeover switch is peace of mind more than necessity. On a rural overhead line in the west, where a bad winter can mean several days without supply, a battery with proper backup starts to look less like a luxury.
There Is No Grant for Any of This
Worth stating plainly, because it comes up in nearly every quote conversation. The SEAI Solar Electricity Grant covers solar PV and caps at €1,800 in 2026. It does not cover home batteries, hybrid inverter upgrades bought for backup, or changeover switches.
Backup hardware has to justify itself on what it is worth to you, not on payback. A battery bought purely for backup will not pay for itself in savings. A battery bought for daily self-consumption that happens to also give you outage cover is a different proposition, and that is the maths in our solar and battery guide.
Frequently Asked Questions
Do solar panels work during a power cut in Ireland?
No, not on a standard grid-tied system. The inverter must comply with IS EN 50549-1 with current Irish settings as a condition of connecting to ESB Networks, and that standard requires it to disconnect when it loses the mains supply. Your panels can be generating in full sun and your house will still have no power. Backup requires an inverter that supports island mode plus a changeover switch, fitted by a Registered Electrical Contractor.
Will my solar battery power my house in a blackout?
Only if the system was specified for backup. A standard home battery discharges through the same inverter that shuts down when the grid fails, so a fully charged battery gives you nothing during an outage unless the inverter supports island mode and a changeover switch has been fitted to break parallel with the ESB Networks supply. Ask your installer to confirm backup capability in writing rather than assuming the battery covers it.
Why do solar inverters shut off when the grid goes down?
To protect the people repairing the network. If your system kept generating into a line that ESB Networks had isolated for repair, that line would be live with no indication at the pole, putting technicians at risk of electrocution. The protection is called anti-islanding and it is built into the IS EN 50549-1 standard that every micro-generator inverter connected in Ireland must meet.
Is a changeover switch legal in Ireland?
Yes. ESB Networks states that solar PV, batteries and electric vehicles may be used as standby generation during a loss of mains supply, provided they are designed, installed and tested for correct operation by a Registered Electrical Contractor, using an appropriate changeover switch to break parallel with the ESB Networks mains supply as required by the National Wiring Rules for Electrical Installations. It is permitted, but it is not a DIY job.
How much does it cost to add backup power to an existing solar system?
It depends on what you already have. If your inverter is hybrid and supports island mode, Irish installers put changeover switch work at roughly €800 to €1,500 installed. If you have a standard string inverter, it needs replacing with a hybrid unit first. Adding a battery for backup that works at night costs €4,500 to €7,000 for a 10 kWh unit on top. There is no SEAI grant for any of it.
Can I still earn export payments if I have backup capability?
Yes, in normal operation. Your system runs in parallel with the grid the vast majority of the time and exports surplus as usual under the Clean Export Guarantee. You only island during an outage, and ESB Networks is clear that standby generation cannot be used to sell electricity to the grid. Backup capability does not reduce your export income for the rest of the year.
Connection and standby generation rules from ESB Networks micro-generation guidance, current at July 2026. Storm Éowyn outage figures from ESB press release, 25 January 2025. Grant figures from Citizens Information (grants for solar panels, last edited 10 March 2026). Cost ranges are indicative planning figures published by Irish installers; get a written quote for your own property.