Rota Load Disconnection Alpha Identifiers


On October 6th 2022 the National Grid Electricity System Operator (ESO) published their 2022 – 23 Winter Outlook report. The report was published at a time of unprecedented flux both domestically and abroad, largely stemming from the Russian invasion of Ukraine earlier this year, and outlined a number of scenarios that could occur this winter.  One of the scenarios was the very small possibility of supply shortages, caused when the demand for electricity is higher than the amount being generated. The most extreme scenario would be a period of supply disconnection. This would be an extremely rare event, however, it is important to be aware of how to prepare for this eventuality.

We have created this update to present useful information and a link to the government’s Electricity Supply Emergency Code (ESEC).  The government’s ESEC includes a ‘Rota Load Disconnection’ measure, which is a pre-prepared plan involving power being disconnected from specific areas in turn for part of each day.  The Electricity Supply Emergency Code can be found here:

Electricity Supply Emergency Code – GOV.UK (

What is an Alpha Identifier?

An Alpha Identifier is the letter allocated to business energy customers in a particular block, which is in turn linked to the postcode. If required, the National Grid will refer to these letters when announcing supply emergency measures to inform businesses if their ‘block’ will be impacted.

Where is the Alpha Identifier located on BPG’s invoices?

Business Power and Gas Limited Customers can find their Rota Load Disconnection Alpha Identifier on their invoice on the right-hand-side beneath their MPAN number.

What if I don’t have an Alpha Identifier on my invoice?

Please let us know if you do not have an Alpha Identifier on your invoice. It could be because your postcode might not have been assigned one by the Network Operator or the postcode we have for you is incorrect. If you do not have an Alpha Identifier, please contact us on 0843 504 7799 or and our account services team will assist.

Why is it necessary to implement Emergency Power Cuts?

An emergency power cut is an extremely rare event. They are only used when it’s necessary to protect the wider power network; if there is a serious problem and demand for electricity is expected to exceed the levels of supply available.

How should businesses plan ahead?

National Grid are aiming to provide advanced notification of any planned power cut, to allow businesses to plan ahead. Each distribution area across the UK is divided into 18 blocks which are made up of a number of discrete geographical areas. Each block is assigned an alphabetic letter, known as an ‘Alpha Identifier’. The blocks are allocated to the slots and are designed to allow businesses in any given block 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.  Customers should speak to their insurance companies to understand if any losses are covered.

What is a protected customer?

The Electricity Supply Emergency Code (ESEC) has compiled the criteria for a site receiving Protected Status. This is defined in section 5.2 of the ESEC. Protected customers include hospitals, emergency services, water/sewerage installations etc.

Process for applying to be a Protected Site

To apply to be a Protected Site customers should initially review sections 5.3 and 5.4 of the ESEC. Customers will need to contact their local Distribution Network Operator (DNO) if they believe they fall under any of the criteria of a protected customer.

What if I classify as a Vulnerable Customer?

We request that if you believe you fall under the category of a vulnerable customer in your business activities, that you register for the ‘Priority Services Register’. A vulnerable customer could be someone classified as elderly or medically dependent on electricity (e.g., dialysis machines). Registering for the Priority Services Register can be done by either contacting your local network operator or by e-mailing to allow us to register you on BPG’s Priority Services Register and with the industry.

Useful contact information and resources:

Distribution Network Operators: Emergency contacts – BPG Energy

Priority Services Registration: Getting extra help from your energy network operator – Energy Networks Association (ENA)

Energy Networks Association: What to do during a power cut – Energy Networks Association (ENA)