Power cuts, voltage issues and your low carbon technologies (LCTs)
Here’s what you need to know
Low carbon technologies (LCTs) such as electric vehicle charge points (EVCP), heat pumps, solar panels and battery storage systems are designed with safety in mind. During a power cut or electricity network fault, these systems will either shut down safely or, in some cases, continue operating in a controlled way depending on how they are designed and installed.
Here’s what you need to know
Low carbon technologies (LCTs) such as electric vehicle charge points (EVCP), heat pumps, solar panels and battery storage systems are designed with safety in mind. During a power cut or electricity network fault, these systems will either shut down safely or, in some cases, continue operating in a controlled way depending on how they are designed and installed.
What happens during a power cut or voltage fluctuations?
What happens during a power cut or voltage fluctuations?
- EV charge points have built‑in safety protection that automatically disconnects them from the electricity network during a power cut or electricity network fault
- This prevents electricity flowing back into the electricity network and helps keep customers, engineers and the public safe
- Once power is restored, some charge points may need to be manually reset, usually by switching the unit off and back on. Always refer to the manufacturer’s instructions or online guidance for your specific device.
- EV charge points have built‑in safety protection that automatically disconnects them from the electricity network during a power cut or electricity network fault
- This prevents electricity flowing back into the electricity network and helps keep customers, engineers and the public safe
- Once power is restored, some charge points may need to be manually reset, usually by switching the unit off and back on. Always refer to the manufacturer’s instructions or online guidance for your specific device.
- Solar panel systems are designed to shut down automatically during a power cut
- This is a standard safety feature that prevents electricity feeding back into the electricity network when engineers may be working on it
- When power returns, systems usually restart automatically after a short delay (often around 20 seconds), in line with industry safety standards. Some systems may display status messages or require checks in line with manufacturer guidance.
- Solar panel systems are designed to shut down automatically during a power cut
- This is a standard safety feature that prevents electricity feeding back into the electricity network when engineers may be working on it
- When power returns, systems usually restart automatically after a short delay (often around 20 seconds), in line with industry safety standards. Some systems may display status messages or require checks in line with manufacturer guidance.
- Battery storage systems will usually shut down during a power cut unless they are designed to operate in backup or ‘island mode’
- This is a standard safety feature that prevents electricity feeding back into the electricity network when engineers may be working on it.
- Battery storage systems will usually shut down during a power cut unless they are designed to operate in backup or ‘island mode’
- This is a standard safety feature that prevents electricity feeding back into the electricity network when engineers may be working on it.
What is island mode?
Island mode (sometimes called backup or standby mode) allows a battery system, often alongside solar panels, to safely disconnect from the electricity network during a power cut while continuing to supply electricity to selected circuits within the property. These circuits might include lighting, sockets or other essential equipment. Not all battery systems have this capability, and it must be specifically designed and installed.
- If island mode is available and enabled, selected circuits can continue to run using stored energy (and, in some cases, solar generation)
- If island mode is not available or not enabled, the battery system will safely disconnect and stop supplying power
- Always refer to your installer or manufacturer documentation for advice on operation, restart and reset following a power cut.
- Heat pumps do not export electricity back to the electricity network, so they do not require the same type of protective disconnection as generating equipment
- During a power cut, heating and hot water will pause because the system has no electricity supply
- Once power is restored, heat pumps typically resume normal operation automatically, although some systems may take a short time to reset or rebalance
- As with any electrical equipment, during storms or power cuts customers may choose to switch off or unplug devices as a general precaution, but this is not a requirement specific to heat pumps.
- Heat pumps do not export electricity back to the electricity network, so they do not require the same type of protective disconnection as generating equipment
- During a power cut, heating and hot water will pause because the system has no electricity supply
- Once power is restored, heat pumps typically resume normal operation automatically, although some systems may take a short time to reset or rebalance
- As with any electrical equipment, during storms or power cuts customers may choose to switch off or unplug devices as a general precaution, but this is not a requirement specific to heat pumps.
How can I prepare for a planned power cut or severe weather?
If you are aware of a planned power cut or are preparing for severe weather, there are a few practical steps you can consider:
- If you have solar panels and battery storage with island mode, check with your installer or manufacturer whether this can be enabled in advance and which circuits will remain powered
- Make sure you understand how to safely reset your EV charge point or battery system if a manual reset is required after power is restored
- Follow any manufacturer guidance for safe operation of your equipment before, during and after a power cut.
How can I prepare for a planned power cut or severe weather?
If you are aware of a planned power cut or are preparing for severe weather, there are a few practical steps you can consider:
- If you have solar panels and battery storage with island mode, check with your installer or manufacturer whether this can be enabled in advance and which circuits will remain powered
- Make sure you understand how to safely reset your EV charge point or battery system if a manual reset is required after power is restored
- Follow any manufacturer guidance for safe operation of your equipment before, during and after a power cut.
How do I know if I have battery backup or island mode?
This depends on how your solar or battery system was designed and installed. Your installer or equipment manufacturer will be able to confirm whether your system can operate in backup or island (standalone) mode and which circuits, if any, it can supply during a power cut.
If your system does not support island or backup mode, your generation and storage equipment will be designed to shut down safely during a power outage.
Frequently asked questions
This factsheet provides general information only. Always refer to your installer or manufacturer for guidance specific to your equipment.
This factsheet provides general information only. Always refer to your installer or manufacturer for guidance specific to your equipment.