A grid-tied solar inverter is built to shut down the moment the grid does, so your solar panels stop feeding your house as well as the grid during a power cut. Only a battery with a specific backup circuit changes that, and only when it is wired and configured for it. Once the grid returns, the inverter is designed to reconnect on its own, with nothing for you to press or reset. What is worth checking afterwards is whether it all came back: an inverter can restart cheerfully while one string, one optimiser or one microinverter stays dark, invisible from the ground and invisible from a healthy-looking light on the wall. Only your own production history shows it.
Why your solar inverter switches off in a power cut too
Nothing has failed and there is nothing to reset: the equipment is doing what it is built to do. A grid-tied inverter needs a live grid to synchronise with before it can export anything; take the grid away, and there is nothing for it to feed into, so it disconnects. That holds however bright the sun is outside, and it is the detail you are most likely to get wrong about your own system: sunshine does not mean power during a cut.
Reporting a power cut: who fixes the grid, and who doesn’t touch your solar inverter
If the power goes off, the fix sits with the network operator, not with your energy supplier and not with your solar installer. In Great Britain, Ofgem says to report it to your network operator, which you can find on the Powercut 105 website, or call 105. Operators such as Electricity North West answer 105 around the clock, every day of the year.
The 105 service restores the connection to your house. What happens next to the inverter behind your meter is yours to check.
In Ireland, report it to ESB Networks on PowerCheck, or call 1800 372 999 (+353 21 2382410 from outside Ireland). The PowerCheck map only shows outages affecting more than ten properties, so a single dead connection, or a fault on a short run of houses, may not appear on it.
What should happen once the power is back
Once the grid is live again, a healthy grid-tied inverter reconnects on its own, and nobody has to flip a switch or press reset. If your display or app is still showing nothing well after the rest of the street has power back, that is no longer a normal wait: work through the checks further down.
What can go wrong instead, and why it still looks fine
Two things can go wrong after that, and they look different from the outside.
The first is loud: the inverter itself does not come back. It sits in a fault state rather than resuming (a tripped isolator, a fault the outage exposed rather than caused, ageing electronics that did not like the surge), and there is no production at all. That is a full stop, and it is covered step by step in the inverter offline / not producing triage.
The second is quiet. The inverter comes back, production resumes, the app shows a number again, and everything from the ground looks completely normal, but one string, one optimiser or one microinverter does not rejoin it. The rest of the array carries on, so the system is producing, just less than it should, and nothing about it announces itself. No error code appears and no light turns red: the light on the wall looks perfectly healthy while the system is down a third or a half of one string.
A third pattern can confuse you for a different reason: monitoring and production can come back out of step with each other. A router that resets during a long outage sometimes comes back on a different channel, with a new IP address, or, if it was replaced or reconfigured while the power was off, under a different network name entirely. The datalogger can rejoin that network and start talking to the manufacturer’s cloud again while the inverter itself is still sitting in fault, so the app shows a healthy connection while production is actually zero. Or the reverse: the inverter is producing perfectly well, but the datalogger’s wifi details did not survive the router change, so the app shows stale or offline while the panels are fine. Comms and production are two separate questions, and a power cut is exactly the kind of event that can knock their answers out of sync.
None of this is visible from the ground or from a single light. A light on the wall tells you the inverter is switched on; it does not tell you that all of it is.
Why the app is the last place to check this properly
The instinct after an outage is to open the app, see a number, feel reassured, and move on. That instinct is the weak point. Current power, or today’s total climbing, tells you that the parts which are working are working. It says nothing about the part that is not, because a dead string does not subtract itself from the display in any way you would notice by eye. A system running at two-thirds of its capacity still produces a graph that looks like a solar graph: up in the morning, a peak at midday, down in the evening. The shape survives; only the height is wrong, and the app gives you no reference for what the height should have been.
The only thing that actually answers the question: your own production history
The number that settles it is one you already have: your daily production (from the manufacturer app, or a monthly report) for the days after the power cut, compared against the days immediately before it, and against what the weather was actually doing on each of those days, because a lower total on a duller day is weather, not a fault. Check your solar production against the weather sets out that comparison properly: a reference for what your roof should have produced given the sky, held against what it actually reported.
Run it for the week after the outage. If the ratio of actual to expected sits roughly where it sat the week before, everything came back, including the part you cannot see from the ground. If it is sitting noticeably lower, and stays there past the ordinary noise of a few cloudy days, something did not reconnect, and you now have a number to put in front of an installer rather than a feeling.
Solmiro runs that comparison for you every day: it works out what the weather over your roof allowed, and it e-mails you when production falls well short of that or stops. Connecting is free.
If a battery or a backup circuit is part of your system
Everything above describes a plain grid-tied system, which is what most solar installations are: no battery, no backup, power cut means the inverter stops until the grid returns. A battery changes that only under specific conditions, and owning one is not the same as having power during a cut.
GivEnergy, a UK battery and inverter maker, puts the condition plainly: “With the correct inverter and backup configuration, a battery can power essential circuits during power cuts.” A battery installed purely to shift your own midday surplus into the evening, with no backup circuit wired in, does exactly that job and nothing more. Ask whoever installed yours which kind you have. What a home battery for your solar panels actually does goes through the sizing and the backup question in more detail.
If it still hasn’t come back
If the display shows zero or an error well after the rest of the street has power, or the app is still stale after a day or more, stop waiting for it to sort itself out. Solar inverter offline, or not producing? is the fifteen-minute triage for exactly that: reading the inverter’s own display or LEDs per brand, checking the breaker and the meter, and working out whether what you have is a comms fault, a production fault, or the partial fault described above, before you call anyone out.
Questions owners ask
Do solar panels work in a power cut?
Not in the way people expect. A grid-tied inverter — the kind most home solar systems use — shuts down automatically the moment the grid does, so the panels stop feeding your house as well as the grid. That's the inverter working correctly, not failing. Only a battery with a specific backup circuit changes it, and only when it's wired and configured for that.
Why does my solar inverter switch off in a power cut?
Because a grid-tied inverter needs a live grid to synchronise with before it can export anything, and a power cut removes that. It disconnects by design, however bright the sun is, and reconnects on its own once the grid is back.
Will my solar panels turn back on by themselves after a power cut?
The inverter is designed to reconnect on its own once it detects the grid is back, with nothing for you to switch or reset. What's worth checking afterwards is whether all of it came back — an inverter can resume happily while one string or one microinverter stays dark, and that isn't something a light on the wall will show you.
How do I know if my solar panels are still working properly after a power cut?
Not from the app alone, and not from looking at the panels. Compare your daily production for the days after the power cut against the days immediately before it, and against what the weather allowed on each of those days — our guide to checking production against the weather sets out how. If the numbers hold up, everything reconnected; if they don't, something didn't.
Does a home battery keep the lights on in a power cut?
Only if it's wired and configured for it. GivEnergy, a UK battery maker, puts it plainly: 'With the correct inverter and backup configuration, a battery can power essential circuits during power cuts.' A battery that is only set up to store your own solar surplus is not configured for that.