UK grid frequency, live
The grid is running at 50.108 Hz, 108 mHz above 50.
Live data, updated .
Grid frequency: how steady it is
system frequency, last hour
108 mHz above 50, inside the normal band.
the numbers
more supply than demand pushes it above 50. NESO keeps it within 0.2 Hz either side
More on grid frequency →Why frequency matters
Every generator on the grid spins in step at 50 Hz. Frequency is the grid's instant balance gauge: it rises when there is more power than demand and falls when there is less. Most of the time the wobble is a few hundredths of a hertz, handled by batteries and power stations that adjust automatically. Larger dips, after a big power station or cable trips, are what the grid's reserves are there to catch.
Common questions
What is the UK grid frequency?
Britain's grid runs at 50 hertz: the alternating current changes direction 100 times a second. The exact figure drifts a little above or below 50 every second as supply and demand move.
What does it mean when frequency goes above or below 50 Hz?
Above 50 Hz means slightly more power is being generated than used; below 50 Hz means slightly less. NESO keeps it within 49.8 to 50.2 Hz in normal operation, and the legal limits are 49.5 to 50.5 Hz.
What happens if the frequency drops too far?
Fast-acting reserves, such as batteries, respond within a second or two. If frequency falls much further, automatic systems disconnect some demand to protect the grid, as happened on 9 August 2019 when two large generators tripped and frequency fell to about 48.8 Hz, cutting power to around a million customers.
Is the frequency the same everywhere in Britain?
Yes. The whole of Great Britain is one synchronous grid, so the frequency is the same in every socket at the same moment. Ireland and continental Europe run their own grids at 50 Hz, linked by direct-current cables.