Will Your Solar Battery Work in a Power Cut or Blackout? (Ireland 2026)
Short answer: most home batteries in Ireland switch off during a power cut. Unless your installer fitted a backup (EPS) circuit or a backup gateway, your solar and battery shut down the moment the grid goes, by law, to protect ESB crews working on the lines. With winter storms on the way, here is how to check yours, what backup actually costs, and how long a battery can keep the essentials running.
Why this matters: Storm Éowyn left 768,000 homes and businesses without power
When Storm Éowyn hit on 24 January 2025, ESB Networks reported a peak of 768,000 customers without power, with more than 10,000 faults on the network. Kilkenny, Waterford and Tipperary were among the worst-hit counties on the day. Around one in ten of those customers, roughly 75,000, waited more than a week for power to come back, and some 25,000 homes, farms and businesses were still without electricity 12 days after the storm. Only weeks earlier, Storm Darragh had cut power to about 395,000 customers, with restoration taking around seven days.
Many homeowners with solar panels and a battery were surprised to find their system was dark too.
Why most solar batteries switch off in a power cut
A standard grid-tied solar inverter must disconnect when the grid fails. This is called anti-islanding protection, and it stops your panels sending power back into lines that ESB crews believe are dead. The battery is connected through the same inverter, so it stops as well, even if it is fully charged.
We supply and fit batteries and inverters across Ireland, with the €600 SEAI battery grant (5kWh or more) handled for you.Battery storage & the €600 grant
To keep power on, your system needs one of these:
- An EPS or backup output on a hybrid inverter, wired to a separate backup circuit (for example the fridge, router, lights and boiler controls).
- A backup gateway or automatic changeover (such as the Sigenergy Gateway or Tesla Backup Gateway) that isolates your home from the grid and runs it from the battery.
Both need to be planned and wired in by your installer. Many systems in Ireland were fitted without them to keep the price down.
How to check if your battery will work in a power cut
- Look at your inverter or battery paperwork for the words EPS, backup, off-grid output or backup gateway.
- Check your fuse board for a separate, labelled backup or EPS board or circuit.
- Look in your monitoring app for a backup or EPS setting, and whether it is switched on.
- Ask your installer directly: “If the grid goes down, which circuits stay on, and for how long?”
If the answer is “nothing stays on”, backup can often be added to an existing system. Ask us to check yours.
How long can a battery keep the essentials running?
A rough guide for a typical Irish home running essentials only: fridge-freezer, Wi-Fi router, LED lights, phone and laptop charging, a TV, and the controls and pump for an oil or gas boiler. That comes to roughly 2.5 to 3kWh a day. Electric showers, immersions, cookers, kettles and heat pumps use far more and are usually left off the backup circuit.
| Usable battery capacity | Essentials only (about 2.5–3kWh a day) |
|---|---|
| 5kWh | About 1.5 to 2 days |
| 10kWh | About 3 to 4 days |
| 15kWh | About 5 to 6 days |
These are estimates. Your own figure depends on your appliances and how full the battery is when the power goes. In winter, solar panels add only a little each day, but on a bright day they can partly recharge the battery and stretch these times further. For a full-house backup, a larger battery and a properly sized inverter are needed.
No solar battery? Portable backup for power cuts and blackouts
If you don’t have solar, rent your home, or live in an apartment, a portable power station is the quickest way to get blackout backup. It’s a large rechargeable battery with normal sockets: charge it from the mains or a folding solar panel, and when the power goes, plug your fridge, router, lights and phone chargers straight into it. No electrician, no wiring changes, and it switches on instantly.
- Essentials for a night (router, lights, phones, laptop): around 1kWh, e.g. BLUETTI Elite 100 V2.
- Fridge, router and lights for about a day: around 2kWh, e.g. BLUETTI Elite 200 V2.
- Longer storms or bigger homes: 3kWh and up, expandable, e.g. BLUETTI Elite 300 or Apex 300.
Irish Wind & Solar is an official BLUETTI partner in Ireland. See BLUETTI Ireland for the models we recommend, or our guide to backup power and solar for apartments.
What backup costs and the grants available
Adding backup to a new battery install usually costs a few hundred euro more for an EPS circuit, or more for a whole-house gateway. Retrofitting an existing system depends on your inverter. The SEAI pays €600 towards a home battery of 5kWh or more alongside the solar PV grant, and homes on certain social welfare payments can get up to €9,000 for solar and a battery.
Farms and businesses
For farms, a power cut can mean no milking, no water pumps and no cooling. A battery with backup can keep critical loads running for hours, and a properly sized generator changeover is still worth having for longer outages. See farm solar or book a free energy audit for your business.
Common questions
Will my solar panels work in a power cut?
Not on a standard grid-tied system. They shut down with the grid for safety. They only keep working if your inverter has a backup output or a backup gateway is fitted.
Can I add backup to my existing battery?
Often, yes. Many hybrid inverters have an EPS output that was simply never wired in. Some systems need a gateway or an inverter upgrade.
Is a generator better than a battery?
A generator can run for days on fuel but is noisy and must be used outdoors. A battery switches over automatically and silently. Many rural homes and farms use both.
Not sure if your battery would keep the lights on? Irish Wind & Solar can check your system and quote for backup. Call 083 480 0023 or get in touch.
Sources: ESB Networks Storm Éowyn updates (January 2025); RTÉ News, 24 January 2025; The Irish Times, 4 February 2025; Irish Examiner reporting of ESB Networks figures. Backup run times are Irish Wind & Solar estimates.
Related: fitting backup? Read why a backup gateway needs an isolator in your meter cabinet, and what EirGrid blackout warnings mean.
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