Frequency response services

We have a licence obligation to control system frequency at 50Hz plus or minus 1%. We make sure there is sufficient generation and demand held in readiness to manage all credible circumstances that might result in frequency variations. On this page you can find out more about the different types of frequency response.

Solar panels

Dynamic Containment

Dynamic Containment is the first of our new end-state services, in order to meet our most immediate need for faster-acting frequency response.

National Grid ESO - windmill in field

Dynamic Moderation (DM)

Dynamic Moderation (DM) rapidly delivers with the aim of assisting the ESO to keep frequency within operational limits.

National Grid ESO - North sea offshore wind farm project - Stay up to date

Dynamic Regulation (DR)

Dynamic Regulation (DR) is a pre-fault service designed to slowly correct continuous but small deviations in frequency.

National Grid ESO - Early Competition Plan - Our progress - project reviewing digital whiteboard

Balancing services website review

We are making improvements to our website to make it easier for you to find the information and support you need. As part of this, we are reviewing the structure of our balancing services area. We've put together a short exercise to help us understand where you would expect to find certain information. If you could spare 5 to 10 minutes to complete this, we'd really value your input.

Take part in the balancing services review

System frequency is a continuously changing variable that is determined and controlled by the second-by-second (real time) balance between system demand and total generation. If demand is greater than generation, the frequency falls while if generation is greater than demand, the frequency rises.

There are two categories of frequency response.  

Dynamic frequency response is a continuously provided service used to manage the normal second by second changes on the system

Non-dynamic response is usually a discrete service triggered at a defined frequency deviation.

Frequency data

You can find real-time data, such as demand data and frequency data over the last 60 minutes, on our Realtime Extranet site.

For historic frequency data, please visit the page Historic Frequency Data.