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Emergency Power Cuts

Emergency power cuts – which are used in response to a national energy emergency at times of severe shortage of electricity generation in the UK – are still unlikely this winter, but we want to ensure our customers and communities are as prepared as possible by explaining more on what this might mean for you.

National Grid Electricity System Operator (NGESO) is responsible for balancing energy supply and demand and ensuring there is enough electricity generated to power homes and businesses. If we have an extreme shortage, it might be deemed necessary for NGESO to instruct SP Energy Networks and other network operators to implement emergency power cuts. In that scenario, we are legally required to act on instructions given by National Grid and UK Government.

We have therefore put together more information on what you need to know should that happen and how you can be as prepared as possible this Winter – including tips and advice for business owners. Please refer to our information leaflets below and further information / FAQs on this page.

Prepare your business for a power cut.

For further information, including identifying your block letter (more on that below on this page) and details on any current incidents, please refer regularly to

Should emergency power cuts be implemented, the associated rota will also be published on

Click here to jump straight to frequently asked questions.

An electricity shortage - what happens?

It’s important to know that before any emergency planned power cut instruction is given, National Grid ESO takes several steps to protect customers. These include:

  • Encouraging additional generation through the supply market.
  • Asking heavy industrial users to limit their demand during peak periods.
  • Reducing domestic power demand – this could include paying customers to change how and when they use appliances like washing machines and dishwashers or reducing voltage across the country by a small percentage, which would be undetectable.

Procedures for emergency planned power cuts like this have existed for decades and are simulated in emergency exercises by the energy sector each year. If National Grid determine it’s necessary to instruct SP Energy Networks to implement emergency power cuts, we might not get much notice and may have to implement these immediately. We would be legally required to act on these instructions given by both National Grid ESO and the UK Government.

If needed, the emergency procedures are designed to minimise the impact on customers as far as possible, by limiting power cuts to shorter periods in order to manage overall electricity demand. However, while the winter is expected to be challenging, there is no guarantee emergency measures will be necessary.

If an emergency power cut is implemented, customers in certain parts of the country would typically be without power for around three hours per day during the emergency, but this could depend on the situation at the time.

Longer-duration power cuts

Distribution network operators, which run the local power networks, would be legally instructed by National Grid ESO, which controls the flow of energy around the country, to disconnect power supplies using established procedures.

These procedures are set out by the government in a document known as the Electricity Supply Emergency Code, sometimes referred to as ESEC or Rota Load Disconnection.

The procedures make sure that power is shared fairly across all customers during a national energy emergency.

  • The purpose of Rota Load Disconnection is to control/reduce the demand for electricity to the level of generation that is available.
  • This is achieved by dividing all users of electricity into groups called ‘blocks’; a customer's block is determined by their postcode and position on the local network.
  • These blocks are then switched off in turn, on a ‘rota’, for a period of three hours. If the level of electricity shortfall increases, more blocks are switched off resulting in interruption to a larger number of customers.
  • Once introduced Rota Load Disconnections will continue for the full duration of the shortfall in electricity generation.
  • The Schedule of Emergency Power Cuts will be published through national and local TV and/or radio stations. It will also be available to view on 

There are government guidelines which allow a very few essential organisations to remain on supply during Rota Load Disconnection (these companies MUST however reduce their electricity consumption). These are referred to and categorised within the Protected Site List. An example of a ‘Protected Site’ could be: a vital service such as major hospitals, airports or water treatment sites, major food manufacturers or a significant manufacturer with continuous 24/7 processes (e.g. steelworks, glass producers).

Tips on being prepared

  • If you run a business, think about what may be impacted if you do not have power and how you might be resilient in such an event.
  • When the power goes off, switch off electric heaters and cookers to avoid a fire risk when the power is restored.
  • It’s always best to switch off and unplug equipment but leave a light on to tell when the power is restored. It may help if you can turn off your central heating time switch while the electricity supply is off.
  • Fill a vacuum flask with hot water boiled in the kettle and recharge mobile phones and rechargeable batteries for torches before the supply goes off.
  • Household cordless phones don’t work without electricity, so consider having a basic wired telephone in case of emergencies.
  • Keep fridge and freezer doors closed. Contents should be safe for many hours but, if in any doubt, dispose of the food if it appears to have defrosted.
  • Check on elderly or infirm neighbours and make them aware of the electricity supply interruption situation.
  • To keep warm, stay in one room, or even in bed, and remember gas and oil central heating boilers generally won’t work without electricity to power their pumps.
  • When using an alternative form of heating or lighting - use it safely.  BBQ’s should not be brought indoors.
  • Listen out for information on local radio — use your car radio if you don’t have a battery radio.
  • It may be necessary to adjust time switches and clocks when your power returns.
  • Back up your computer work before the power is expected to go off.
  • A battery back-up alarm clock may be useful for any overnight or early morning power interruptions

In order for us to provide the best possible service during a scenario like this or any other network outages, it’s important we have your correct contact details. Please therefore take a moment to update your details with us: Update Your Details

Click here for more information on being prepared: Preparing for a power cut

More information and Frequently Asked Questions 

What is a network operator?

You can choose who supplies your energy. This company known as your energy supplier and they bill you for the energy you use. Your network operator is different. They manage and maintain the wires, pipes and other infrastructure which delivers electricity and gas to your home, business and community.

How can I find out who my local network operator is?

If you live in Central and Southern Scotland, North Wales, Merseyside, Cheshire and North Shropshire, there is a very good chance SP Energy Networks is your network operator. However, if you are unsure you can find out who your operator is by entering your postcode at

Your network operator is who you should call if there is a power cut as they are responsible for the network of towers, transformers, poles, cables and meters that deliver power to your home. If you are experiencing a power cut go online to your local network operator’s website to report the problem or call 105 – this is free from most landline and mobile numbers and will put you straight through to your Distribution Network Operator.

What is an emergency power cut?

Emergency power cuts mean switching power off to at least 5% of UK households at once. They can take place without warning, if National Grid ESO instructs local networks to reduce power demand in the local area to protect the electricity grid and avert longer term issues.

However, where possible, National Grid ESO plans to implement a national timetable of power cuts to fairly share power across the country.

The electricity system in Great Britain is sectioned into blocks that can be temporarily switched on and off, typical for three-hour periods, until the shortage is resolved, and the network can safely go back to normal.

Each electricity meter is assigned a ‘block letter’. In the event of an emergency power cut, where there is time to implement an emergency rota, different block letters will be timetabled to be without power for around three hours once or twice a day.

Why would emergency power cuts happen?

Russia’s invasion of Ukraine means that overall, this is likely to be a challenging winter for energy supply throughout Europe.

If there isn’t enough electricity to power every home and business in Britain at the same time, the Electricity System Operator (otherwise known as National Grid ESO) – which is responsible for ensuring there is enough power to meet demand – could instruct the companies which operate the local power network to reduce electricity demand through emergency power cuts.

Before this happens, there are a number of tools National Grid ESO can use. These include increasing the amount of power being generated, asking large industrial customers to reduce the amount of power they’re consuming and paying customers – through their energy supplier – to use less energy at certain times.

Emergency power cuts are only implemented to protect the electricity network from more damage, which would be more disruptive to customers for a much longer period. They are a last resort and wouldn’t affect everyone at the same time.

How likely are emergency power cuts?

Emergency power cuts are unlikely this winter. It’s important to know that before any emergency planned power cuts occur, National Grid ESO undertakes a ‘winter outlook’ every year which helps to inform the electricity industry and prepare for the winter ahead. There are a number of additional factors to consider this year, but it is normal for a winter outlook to be published.

As part of this process, National Grid ESO takes several steps to protect customers. These include:

  • Asking companies to generate more power to meet the demand and switching on generators which aren’t currently supplying power to the market.
  • Asking heavy industrial users to limit how much power they use during certain periods.
  • Reducing household power usage – this includes paying customers to change how and when they use appliances like washing machines and dishwashers or reducing voltage across the country by a small percentage, which would be undetectable.

How are rotas devised?

Each distribution area across the UK is split into 18 blocks which are each made up of a number of discrete geographical areas.  Each of these blocks is assigned a letter between A and U. The letters F, I and O are not used.

In the event of an emergency power cut, different block letters are timetabled to be without power for typically around three hours once a day (however, depending on the severity of the scenario, power may be interrupted multiple times over the period of the event).

Each day of the week is split into 8 three hour SLOTS. The first slot of the day starts at 00:30.

The blocks are allocated to the slots in a way that allows businesses to operate as normally as possible for 3 days in succession. This means that power cuts will either be concentrated between Monday and Wednesday or Thursday and Saturday, with Sunday being shared between all blocks. The more severe the emergency, the greater the number of blocks that will be switched off at the same time.


How can I find my personal power cut timetable (rota)?

Before an emergency power cut starts, a timetable will be available at

The timetable will tell you when you will definitely be without power, and when there is a risk, you may be without power. Your power might be switched off or reconnected around 30 minutes before or after the published time depending on national electricity use at that time. This is because of the need to phase disconnections and reconnections, creating a short overlap.

If your power is not restored within an hour, please check our website for more information and to report your power cut.


Could I still be affected by emergency power cuts even if my rota block is not affected?

Even if your rota block is not confirmed for disconnection you should be aware that, in isolated instances, due to the large scale of emergency power cuts, there is a possibility that you may experience some short duration (< 3min) effects. For example, dimming of lights or low power. Please only contact us if you continue to experience these issues for more than an hour after the emergency power cut.

Where can I find my block letter? What if I can't find it?

You can find your block letter by entering your postcode at

It should also be printed on the top half of your electricity bill in a small square. If you can’t find it, you should contact us by calling 105.

How will you know if emergency power cuts are being implemented?

In the unlikely event of emergency power cuts becoming necessary, a rota will be published on – please note, this information will only be made available if a rota is implemented.

National campaigns will be rolled out, with information being available alongside the rota on

*Please note – due to the emergency nature of this sort of scenario, it may not be possible for customers to be given notice ahead of any emergency power cuts being implemented.

How often will I be switched off?

The electricity supply will be turned off to certain areas, or blocks, for three hours at a time, depending on the shortage of electricity. This could be affected by the weather, the time of day and the demand for electricity.

At the lowest level of emergency, you could expect to be without electricity for just three slots in a week. However, if there is a severe shortage of electricity, you may be without supply for several slots in a week. You will receive 48hrs notice of Emergency Power Cuts being introduced.

What do I do if my electricity does not come back on when I expect it to?

If your electricity supply has not been restored after four hours, please call us on 105.

Customers medically dependent on electricity

In most cases, customers who are medically dependent on electricity will be familiar with the process and limitations of their equipment as power cuts can occur from time-to-time during a typical year, including during severe weather, for regular maintenance or due to damage and other routine faults.

These customers often have backup power sources to keep vital equipment powered for several hours during a power failure. 

Customers who require a continuous supply of electricity for medical reasons and would need medical support during a power cut, should seek advice from their local health service provider.

Backup power supplies and associated equipment should be regularly checked and maintained by a competent person. If you're concerned, you should speak to your medical equipment or health care provider now.

If emergency power cuts are needed customers will be able to find their rota and what it means for them at by entering their postcode. The rota will only be published once emergency power cuts have been approved to take place.

Priority Services Register

I’m on the Priority Services Register. How much notice will I get?

Power cuts can occur at any time, without notice.

In the event of an emergency power cut, it won’t be possible for us to give you advanced notice in the way we normally would for a planned outage. This is because we as a Distribution Network Operator may only receive as little as 30 minutes’ notice of an instruction for them to implement a power cut.

We are contacting customers on the Priority Services Register now, to ensure we have up-to-date information and to remind them about being prepared for winter.

Whenever possible, we will begin contacting customers in advance of a rota coming into operation.

Please note that in the event of emergency power cuts being implemented, all customers will be impacted regardless of PSR status.


I have a stairlift- what should I do, and how can I prepare?

Stairlifts often have backup batteries. You should check how long your backup battery is expected to last. If you are unsure, you should speak to your manufacturer.

Emergency power cuts are expected to last around three hours, once or twice per day. A timetable will set out who will be without power and when. You should make sure you have access to a ground floor exist, telephone and heating for the duration of the time you are scheduled to be without power.


Why can’t you protect me from these power cuts?

Distribution Network Operators like us are legally required to implement power cuts, when instructed by National Grid ESO. We are not allowed to protect customers from power cuts unless those customers have been classified as a ‘protected site’ under government and National Grid ESO rules.

Sites protected from emergency power cuts

Are any sites protected from the power cuts?

A very limited number of sites are protected from emergency power cuts. These are typically locations which are deemed to be critical national infrastructure, such as air traffic control centres and major hospital facilities with accident and emergency departments.

Can my home or business become a ‘protected site’?

Homes cannot become ‘protected sites’ as they are not critical national infrastructure.

Organisations which are not already aware of their protected status will need to apply to become ‘protected’ as this is not automatic. There is very strict qualifying criteria set out by the Government, and more information on this is provided via the Electricity Supply Emergency Code procedures.


What about hospitals?

Most hospitals have backup generators to ensure they can continue to operate in the event of power disruption.


What about hospices, care homes, schools and other core services?

Business continuity plans will vary across specific organisations and service providers. Power cuts can occur at any time so most will have plans in place. Whilst National Grid ESO’s base case scenario does not expect any planned power disruption, it’s sensible to review any additional risks from three hours without electricity, as a precaution.

Businesses which are responsible for caring for vulnerable customers are always encouraged to ensure they have robust business continuity plans in place, which may include investing in their own emergency backup generator system. Find out more about preparing your business for a power cut via our winter preparedness guide available on our website: Preparing your business for a power cut

Using portable generators

You should not connect portable generators to your home wiring unless you have had a proper connection installed by an authorised person. An incorrectly connected generator could cause danger to yourself and your electrical equipment.

How do I participate in a demand flexibility service?

It may be possible to avoid some power cuts by reducing the amount of electricity you are using.

Please turn off every non-essential item, such as dish washers or tumble dryers, and minimise the use of electric cooking. Also, unplug all equipment that has a standby feature — they use electricity even when you are not using them.

A Demand Flexibility Service (DFS) has been developed to allow National Grid ESO (NGESO) to access additional flexibility when the national demand is at its highest - during peak winter days - which is not currently accessible to the ESO in real time. This new innovative service will allow consumers, as well as some industrial and commerical users (through suppliers/aggregators) to be incentivised for voluntarily flexing the time when they use their electricity.

Find out more on the NGESO website by clicking here.


Can I claim compensation?

No. Under Ofgem rules, compensation is not available for an emergency power cut of this nature.


Will I still be charged for electricity?

You will only be charged for the amount of electricity you use.



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