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How Britain's electricity system works

Who generates, moves and sells electricity in Great Britain, and how the system is kept in balance.

From power station to plug

  1. Step 1GenerationPower stations, wind and solar farms, and imports through cables from other countries.
  2. Step 2TransmissionThe high-voltage network carries power long distances, from generators to the regions.
  3. Step 3DistributionYour local network operator steps the voltage down and runs the wires to streets and homes.
  4. Step 4Your homeYour meter records what you use. Your supplier buys the energy and sends the bill.

Your supplier is separate. It buys energy on your behalf and bills you, including the network companies' charges. If the power goes off, contact the network operator (call 105), not your supplier.

The system right now

Electricity demand

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Unavailable

Generated in Great Britain

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Named sources, same snapshot

Net imports

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Through interconnector cables

Grid frequency

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Frequency over the last hour

Frequency stays close to 50 Hz when supply and demand match. It rises a little when there is more generation than use, and falls when there is less; NESO keeps it within set limits by changing generation and demand.

Data currently unavailable · Source: Elexon BMRS FREQ · Great Britain · Hz

Who does what

  • NESO

    Balances and operates Great Britain's electricity system second by second, and plans the system for the future. Publicly owned since October 2024, separate from National Grid.

    Official site →

  • National Grid Electricity Transmission

    Owns, builds and maintains the high-voltage transmission network in England and Wales.

    Official site →

  • SP Transmission and SSEN Transmission

    Own and maintain the transmission network in southern and northern Scotland.

    Official site →

  • Distribution network operators

    Run the local networks and fix local power cuts. There are six in Great Britain, such as National Grid Electricity Distribution and UK Power Networks.

    More →

  • Energy suppliers

    Sell you energy, set your tariff and handle your bills. They don't run the wires.

    More →

  • Ofgem

    Regulates the energy market and the network companies in Great Britain, including the price cap.

    Official site →

  • National Gas

    Owns and operates Great Britain's high-pressure gas transmission system. NESO does long-term gas planning, but doesn't run the gas network.

    More →

This covers Great Britain. Northern Ireland has its own system: SONI operates it and NIE Networks owns the network, as part of a single electricity market with Ireland.

How it stays balanced

Balancing

Electricity can't easily be stored in bulk, so the amount generated must match the amount used at every moment. Generators and suppliers plan ahead in half-hour periods; NESO then adjusts in real time, paying some generators to increase or reduce output, and calling on batteries, pumped storage and flexible demand.

Imports and exports

Undersea cables link Great Britain to France, Belgium, the Netherlands, Norway, Denmark, Ireland and Northern Ireland. Power flows towards the market where it is worth more at the time, so Britain imports at some times and exports at others.

Network constraints

Sometimes the wires between regions can't carry all the power available, for example from Scottish wind farms to the south. NESO then pays generators on one side to turn down and others to turn up. These constraint payments are part of balancing costs, which also include other services.

A local fault isn't a national shortage

Almost all power cuts are caused by faults on local distribution networks, such as a damaged cable or storm damage to overhead lines, and are fixed by the network operator. A national shortfall in generation is rare and is managed by NESO, which has emergency arrangements in place.

Related

Check for a power cut →Find your network operator and listed incidents.Your area →Your network region, carbon and local prices.Live generation →What is powering Great Britain now.Why is my bill high? →Check your bill in three questions.
Sources