UK's Trusted Solar Installer 
Excellent 
Will Solar Panels Work in a Power Outage?Why Do Solar Panels Switch Off During a Power Cut?How Can Solar Panels Work When the Power Goes Out?What Is Islanding Mode and Why Is It Important?Do All Batteries Include Backup Power?What Can You Power During a Power Outage?How Long Can a Solar Battery Power Your Home During an Outage?Can You Add Backup Power to an Existing Solar System?Common Myths About Solar Panels in BlackoutsDo Solar Panels Work in a Power Cut FAQs
Will Solar Panels Work in a Power Outage?Why Do Solar Panels Switch Off During a Power Cut?How Can Solar Panels Work When the Power Goes Out?What Is Islanding Mode and Why Is It Important?Do All Batteries Include Backup Power?What Can You Power During a Power Outage?How Long Can a Solar Battery Power Your Home During an Outage?Can You Add Backup Power to an Existing Solar System?Common Myths About Solar Panels in BlackoutsDo Solar Panels Work in a Power Cut FAQs
Many people assume their solar system will automatically provide backup, but it's important to understand that the reality is more nuanced.
Most standard grid-tied solar systems switch off during a blackout for safety reasons. However, with the right equipment, such as a battery storage system, hybrid inverter, or emergency power supply (EPS) function, your solar panels can still generate and power your home during an outage.
In this guide, we explain how solar behaves in a power cut, why most systems shut down and what upgrades can keep your lights on when the grid goes dark.
Ready to see your solar savings? Fill in the form below for a free, no-obligation quote designed for your property:
In most cases, standard grid-connected solar panel systems will not work during a power outage. This is a built-in safety feature, not a design problem, to protect utility workers and prevent damage to the grid.
When the electricity grid goes down, your solar inverter automatically shuts off. This stops solar energy from feeding back into the power lines, which could otherwise create a hazard for engineers repairing the network.
So, if you have a typical grid-tied setup without additional backup equipment, your solar panels won’t supply power to your home during a blackout, even if it is a sunny day.
However, certain systems can keep working. Homes equipped with battery storage, hybrid inverters or emergency power supply (EPS) functions can continue using solar energy when the grid fails. We'll touch on this more later in the article.
Solar panels switch off during a power cut to protect utility workers and the electrical grid. This automatic shutdown is a legal and safety requirement for all grid-tied systems.
When the grid goes down, engineers may need to work on power lines to restore electricity. If your solar system kept feeding energy into the grid, it could create a live circuit, putting those workers at serious risk.
Your solar inverter is designed to detect grid failures instantly. As soon as it senses a power outage, it disconnects your system to prevent any electricity from flowing back into the network.
This safety feature is called 'anti-islanding.' It ensures your home doesn’t become an unintended power source during an outage, which could also damage appliances or your own system.
While it may seem frustrating that your panels don’t work when you need them most, this shutdown mechanism is essential for everyone’s safety. The good news is that with the right backup equipment, you can still enjoy solar power during outages.
Want to learn more about how solar panels perform in different conditions? Explore our related guides:
Solar panels can work during a power outage, but only if your system includes specific backup equipment. Standard grid-tied setups will always shut off, so you’ll need additional components to keep generating and using solar energy.
The most common solution is a home battery storage system. Batteries store excess solar energy generated during the day, then release it when the grid fails. Paired with a compatible inverter, this allows your home to run on solar power even during a blackout.
Another option is a hybrid inverter with an emergency power supply (EPS) function. These inverters can automatically switch your home into 'island mode' during an outage, letting your panels power essential circuits directly.
For whole-home backup, you can combine solar panels with a larger battery bank and a critical loads panel. This setup powers more appliances and keeps your home running longer when the grid is down.
While these upgrades come at an extra cost, they provide energy independence and peace of mind. If reliable backup power is important to you, talk to a qualified solar panel installer, such as Glow Green.
To keep your solar panels working during a blackout, you’ll typically need:
✓ A battery storage system
✓ A hybrid inverter or inverter with EPS/islanding capability
✓ A critical loads panel or dedicated backup circuit
✓ Professional installation and grid-compliance approval
Islanding mode is a feature that allows your solar system to disconnect from the grid and power your home independently during a blackout. This is essential for keeping your lights and appliances running when the grid fails.
When a power outage occurs, most solar inverters automatically shut off to prevent electricity from feeding back into the grid. Islanding mode overrides this by creating a self-contained 'island' of power, using your solar panels and battery to supply your home safely.
This capability is important because it provides backup power without relying on the grid, keeping your fridge, heating and essential devices working. It also protects engineers by ensuring no stray current flows into power lines during repairs.
Not all inverters support islanding mode. You’ll need a hybrid inverter or a system specifically designed for backup operation, often classed as EPS or anti-islanding compliant.
As we've briefly touched on, no, not all solar batteries include backup power. Some battery systems are designed only for energy storage and self-consumption, meaning they cannot supply electricity to your home during a blackout.
To provide backup power, a battery must be paired with a compatible inverter that supports islanding or EPS functionality. Without this, the battery will disconnect along with your solar panels when the grid fails.
Many modern home battery systems, such as the Tesla Powerwall, GivEnergy and Fox ESS, do offer backup capabilities, but it’s not guaranteed across all models. Always check with an installer, such as Glow Green, on whether the battery supports blackout protection.
If your main goal is to keep your home powered during outages, confirm that both the battery and inverter are backup-ready before purchasing.
The appliances and devices you can run during a power outage depend on your backup system’s capacity, typically measured in kilowatts (kW). Most home battery and solar backup setups are designed to keep essential circuits running, not your entire house.
Commonly powered items during an outage include:
Lights and LED fixtures
Fridge and freezer
Wi-Fi router and phone chargers
TVs and small entertainment devices
Boilers, control panels and smart thermostats
Microwaves and small kitchen appliances (used intermittently)
Medical devices and home office equipment
Items usually not powered by standard backup systems:
Electric ovens and hobs
Electric showers and immersion heaters
Air conditioning units (unless specifically sized for them)
Washing machines and tumble dryers (high draw, often excluded)
Electric vehicle chargers
Whole-home heating systems with high power demands, such as heat pumps
For whole-home backup, you’ll need a significantly larger battery and inverter setup, often at a much higher cost. Most people prioritise essential loads to maximise runtime and value.
The length of time a solar battery can power your home during an outage depends on its capacity, your energy usage and which appliances you’re running. Most home batteries range from 5 kWh to 15 kWh, though larger systems are available.
For example, a 10 kWh battery could typically power essential loads like lights, a fridge, Wi-Fi,and a boiler for 12 to 24 hours, assuming moderate use. If you’re only running minimal essentials, it could last even longer.
However, high-draw appliances like electric showers, ovens or heating systems will drain the battery much faster. That’s why backup systems usually focus on a dedicated 'critical loads' circuit rather than your entire home.
Keep in mind that if your battery is paired with solar panels, it can recharge during daylight hours, extending your backup power significantly. On a sunny day, you might generate enough to run essentials indefinitely, even during a prolonged outage.
Want to learn more about solar battery storage? Explore our related guides:
Yes, you can often add backup power to an existing solar panel system, but it depends on your current inverter and setup. If you have a standard grid-tied inverter, you’ll need to upgrade to a hybrid inverter or add a separate backup-capable inverter to enable islanding during a power cut.
One common approach is to install a home battery system that’s compatible with your existing solar array. Many modern batteries can integrate with legacy solar setups, provided the inverter supports AC coupling or has an EPS port.
If your current inverter doesn’t support backup functionality, you may need to replace it with a hybrid model. While this adds to the upfront cost, it’s often more affordable than installing a completely new system, and it unlocks the ability to run essential circuits during outages.
Before proceeding, consult with a qualified solar installer, such as Glow Green, to assess your current equipment and grid compliance requirements. We'll confirm whether your system is retrofit-ready and recommend the most cost-effective backup solution for your needs.
Looking for the right battery to add backup to your system? Read our in-depth reviews:
Despite growing interest in solar energy, several misconceptions persist about how panels behave during power cuts. As we've covered, here’s what’s actually true:
Reality: Standard grid-tied systems automatically shut off during outages for safety. Only systems with backup capabilities, like batteries or hybrid inverters, can keep running.
Reality: Not all batteries support backup power. You need a battery paired with an inverter that offers islanding or EPS functionality to run your home during an outage.
Reality: Most backup systems are designed for essential circuits only, like lights, fridge and Wi-Fi. High-draw appliances (ovens, electric showers, etc.) usually can’t be supported without a much larger, whole-home setup.
Reality: Many existing solar setups can be retrofitted with a compatible battery or hybrid inverter to enable backup power, often at a lower cost than a full replacement.
Reality: While there’s an upfront cost, battery prices have dropped significantly. For many households, the combination of energy savings, increased self-consumption and blackout protection makes it a smart long-term investment.
Most standard grid-tied solar panel systems do not work during a power cut because they automatically shut off for safety reasons. However, systems equipped with battery storage or hybrid inverters that support islanding mode can continue to power your home.
No, not all solar batteries include backup power capabilities, only those specifically designed with islanding or EPS features and paired with a compatible inverter can supply electricity during a blackout.
Yes, if your system includes a compatible battery and inverter with islanding capability, solar panels can continue to charge the battery and power your home during a blackout, provided there’s sufficient sunlight.
If your system has battery storage, it can continue to supply power as long as the battery has charge and the solar panels can recharge it during daylight. Without a battery, your system will remain off until the grid is restored.
Yes, whole-home solar backup is possible but requires a large battery bank, a high-capacity hybrid inverter and careful load management. However, it’s significantly more expensive than backing up only essential circuits.
