Can I Use Solar Energy During Power Outages?

It’s one of the first things people ask when they’re looking at solar panels for their home if the power goes out, will my solar keep the lights on? After storms like Eowyn and Darragh left thousands of Irish homes without electricity for days, it’s a fair question. And the honest answer might surprise you.

The short version? Most solar panel systems in Ireland will not work during a power cut. Not unless they’re specifically set up for it. But with the right equipment, yes, you absolutely can keep your home running on solar when the grid drops out.

Standard grid-tied solar panels shut down automatically during a power outage. This is a safety feature to protect ESB line workers. If you want your solar system to work during a blackout, you need three things: a battery storage system, a hybrid inverter, and a changeover switch. Without all three, your panels will sit idle until the grid comes back.

Why Do Solar Panels Switch Off During a Power Cut?

This catches a lot of people off guard. You’ve got panels on the roof, the sun is out, but the house is still dark. Here’s why.

When the ESB grid goes down, your solar system is designed to shut off automatically. It’s called anti-islanding protection, and it exists for a very good reason. If your panels kept feeding electricity into the grid during an outage, they could send power down lines that ESB crews are working on. That’s a serious safety risk.

So every grid-tied inverter sold in Ireland (and across Europe) has this built in. The moment the grid drops, the inverter stops producing power. Your panels might still be generating electricity from daylight, but it has nowhere to go.

This applies whether you have a string inverter, microinverters, or even a hybrid setup that hasn’t been fully configured for backup. No grid signal means no power to your home.

What Do You Need to Use Solar During an Outage?

If you want your solar system to keep your home running when the power goes, you need a few specific components working together. Miss one and it won’t work.

Battery Storage System

The battery stores excess electricity your panels produce during the day. When the grid fails, this stored energy is what powers your home. Without a battery, there’s simply no way to use your solar during a blackout (your panels can’t send power directly to your circuits when the grid is off).

A typical home battery in Ireland holds around 5 kWh of usable energy. The average Irish home uses roughly 10–12 kWh per day, so one battery covers about half a day. Two batteries will see most families through a full day, especially if you’re being mindful about what you switch on. If you’re considering this option, our guide on solar panel battery storage covers the basics of how these systems work and what to look for when choosing one.

Hybrid Inverter

A standard inverter only converts solar DC power to AC for your home and the grid. A hybrid inverter does that too, but it can also manage battery charging and (here’s the bit that matters) switch your home to battery power when the grid fails.

Not all hybrid inverters support off-grid backup, though. Some are designed purely for self-consumption — storing solar power to use in the evening, for instance — but they still shut down during a power cut. So it’s worth confirming with your installer that the specific model supports backup functionality.

Changeover Switch

This is the piece that physically disconnects your home from the ESB grid and connects it to your battery and panels instead. It’s a legal and safety requirement in Ireland. The changeover switch makes sure you can’t accidentally feed electricity back out to public lines while crews are working on them.

Some systems use a manual changeover switch (you flick it yourself when the power goes), while newer setups from companies like Sigenergy use automatic gateways that switch over the moment mains power drops. Either way, this component must be installed by a registered electrician.

Is It Actually Allowed in Ireland?

This is where things got a bit messy over the past year or two. After storms Darragh and Eowyn, there was genuine confusion among homeowners and even some installers about whether off-grid backup was permitted under Irish regulations.

The good news: Safe Electric confirmed that backup systems are allowed under the National Rules for Electrical Installations (I.S. 10101), as long as the installation is carried out properly by a registered contractor. The SEAI also confirmed that grants are being paid for systems with backup capability, once they meet safety requirements that protect both your household and the wider grid.

There was a brief pause on some grant payments while the safety of off-grid setups was reviewed. That’s since been resolved. But it does highlight why working with an experienced, SEAI-approved installer matters. The wiring for a changeover switch (particularly the neutral treatment) needs to be done right. Get it wrong and you risk damaging your inverter or, worse, causing a fire.

At Going Solar, we’re engineers first. We’ve completed over 8,000 residential solar installations across Ireland, and every system we design is tailored to the property and the homeowner’s needs, including backup requirements if that’s something you want built in from the start.

How Long Will Your Battery Last During a Power Cut?

That depends on two things: the size of your battery and how much electricity you’re using.

Most backup systems are set up to run your essentials — lights, fridge, heating controls, phone chargers, your broadband router. You’re not going to run an electric shower or a tumble dryer off a single 5 kWh battery. But for the things that matter most during a power cut, one or two batteries will keep you going.

Here’s a rough guide for an average Irish home:

• One 5 kWh battery: roughly 8–12 hours powering essential circuits only.
• Two 5 kWh batteries (10 kWh total): a full day or more on essentials, especially if your panels are topping up the batteries during daylight.
• Larger setups (15+ kWh): multiple days of backup, depending on usage.

The advantage of having solar panels alongside the battery is that your panels can recharge the battery during the day, even while you’re off-grid. So during a multi-day outage with some daylight (which is most outages, even in winter), your system keeps cycling — generating, storing, and powering your home.

If you’re looking at how solar and battery systems work together in more detail, we’ve written a full breakdown on how you can combine solar panels with a home battery system that covers compatibility, inverter types, and what to ask your installer.

Should You Plan for Backup From the Start?

If there’s one piece of advice we’d give here, it’s this: if backup power matters to you, mention it before your system is designed. Adding a battery and changeover switch from the start is straightforward and more cost-effective than retrofitting later.

Not everyone needs backup. Power cuts in most urban parts of Dublin and Leinster tend to be short (a few hours at most). But if you’re in a more rural area where outages can last days, or if you have someone medically vulnerable at home, it’s well worth the extra investment.

The SEAI solar grant of up to €1,800 applies to solar PV systems generally, and that can offset a good chunk of the overall cost when you’re budgeting for panels, battery, and backup.

Talk to your installer early. Make sure they’re SEAI-approved, experienced with hybrid systems, and can explain exactly what your setup will and won’t do during a power cut. That one conversation can save a lot of frustration down the line.

Worth Knowing Before You Commit

A backup-capable solar system isn’t just a nice-to-have any more. After the storms of 2024 and 2025, more and more Irish homeowners are asking for it. The technology is proven, the regulations allow it, and the costs are coming down.

But it has to be done properly. Cheap changeover switch installations and unqualified electricians are a real risk. Stick with a registered, SEAI-approved installer who can show you exactly how the system will perform when the grid drops.

If you’d like to find out whether backup solar is right for your home, get in touch with Going Solar for a free consultation. We’ll survey your property, talk through your options, and design a system that works for you — rain, shine, or power cut.

Get a free quote or try our solar calculator to estimate your needs.