It’s one of the biggest surprises for homeowners with solar panels. The sun is shining, your panels are generating electricity, yet as soon as there’s a power cut, everything stops working.
Many people assume their solar panels will continue powering their home during an outage. However, solar panels stop working during a power cut for a very important reason. It’s not because your system has developed a fault. Instead, it’s a built in safety feature that protects both your home and the engineers working on the electricity network.
Quick Answer
Yes, most standard solar panel systems automatically switch off during a power cut.
This happens because the inverter detects that the mains electricity supply has failed. It immediately disconnects from the National Grid to prevent electricity from being sent back into damaged power lines while engineers are carrying out repairs.
Although your solar panels may still be producing electricity, they cannot normally supply your home unless your system has been specifically designed with backup capability.
Why does the inverter switch off?
Your solar inverter is constantly monitoring the electricity network.
If the mains supply disappears, the inverter immediately shuts down. This safety feature is known as anti islanding protection.
Without it, electricity generated by your solar panels could continue flowing onto the National Grid while engineers are repairing damaged cables.
Although it can be frustrating during a power cut, this protection plays an important role in keeping people safe.
Standard Solar vs Solar with Battery Backup
| Feature | Standard Solar | Solar with Battery & EPS |
|---|---|---|
| Generates electricity during daylight | ✅ | ✅ |
| Automatically disconnects from the grid during a power cut | ✅ | ✅ |
| Can supply selected circuits during a power cut | ❌ | ✅* |
| Stores unused solar energy | ❌ | ✅ |
| Helps reduce electricity imported from the grid | ✅ | ✅ |
*Only when the battery system has been designed with Emergency Power Supply (EPS) or backup capability.
What is Emergency Power Supply (EPS)?
Some battery storage systems can be installed with Emergency Power Supply (EPS).
This allows selected circuits within your home to continue operating during a power cut, using energy stored in the battery.
Depending on the system design, this may include:
- Lighting.
- WiFi.
- Refrigeration.
- Selected sockets.
- Essential household appliances.
It’s important to understand that not every battery installation includes EPS as standard. If backup power is something you’d like, it’s best to discuss this with your installer before the system is designed.
Thinking about battery storage?
If you’re planning a new solar installation or looking to upgrade an existing system, it’s worth considering how you’d like your system to operate during a power cut.
Our team can explain the different battery options available, including systems with backup capability, and help you choose the solution that’s right for your home.
Can my existing solar system be upgraded?
In many cases, yes.
If you already have solar panels, it may be possible to add battery storage with backup functionality, depending on your existing equipment.
Many homeowners installed solar panels years ago simply to reduce their electricity bills. Today, battery technology has advanced significantly, giving homeowners the opportunity to store excess electricity and, where appropriate, provide backup power during an outage.
Every property is different, so we’ll always assess your existing system before recommending the most suitable upgrade.
Things to consider
Before choosing a battery storage system, it’s worth asking your installer:
✔ Does this battery support Emergency Power Supply (EPS)?
✔ Which circuits will continue working during a power cut?
✔ Can the battery capacity be expanded in the future?
✔ Will the system work with my existing solar panels?
✔ How much stored energy will be available during an outage?
Asking these questions early helps ensure your system meets both your current and future needs.
Why doesn’t every battery provide backup power?
One of the biggest misconceptions is that every battery storage system will automatically power your entire home during a power cut.
In reality, this depends on how the system has been designed.
Some batteries provide backup to selected essential circuits only, while others can support more of the property with the correct equipment and battery capacity.
This is why it’s so important to discuss your expectations before installation, rather than assuming every battery works in the same way.
Understanding your options
Although solar panels stop working during a power cut, they do so for a very good reason. The automatic shutdown protects electricity network engineers and forms an important part of modern solar installations.
If having electricity during an outage is important to you, battery storage with Emergency Power Supply may be worth considering. However, every property is different, so the best solution depends on your existing system, your electricity usage and your expectations.
At West Coast Electrical & Renewables, we help homeowners choose solar and battery systems that are designed around the way they live. Whether you’re installing solar for the first time or upgrading an existing system, our experienced team can explain your options and recommend the right solution.
