The GB electricity transmission network

Britain’s electricity transmission network transmits high-voltage electricity from where it is produced to where it is needed throughout the country.

The system is made up of high voltage electricity wires that extend across Britain and nearby offshore waters.

It is owned and maintained by regional transmission companies, while the system as a whole is operated by a single Electricity System Operator (ESO).  This role is performed by National Grid Electricity System Operator (NGESO). NGESO is responsible for ensuring the stable and secure operation of the national electricity transmission system.

We have an important role in regulating the activities of these natural monopolies. We seek to protect consumers’ interests by regulating the companies through price control periods where we set the maximum amount of revenue that they can recover from users. These arrangements also seek to incentivise the companies to improve efficiency (keeping costs down for consumers), innovate technically and to act in line with the interests of consumers and other stakeholders.

Most users that take power from the transmission system are connected to the distribution networks across GB.  These networks carry electricity from the transmission systems to industrial, commercial and domestic users.

There are currently three Transmission Operators (TOs) permitted to develop, operate and maintain a high voltage system within their own distinct onshore transmission areas. These are National Grid Electricity Transmission plc (NGET) for England and Wales, Scottish Power Transmission Limited for southern Scotland and Scottish Hydro Electric Transmission plc for northern Scotland and the Scottish islands groups. 

Further detail on the offshore transmission system and offshore TOs can be found in our Offshore Transmission section.

Publications and updates

  • Published: 2nd Nov 2018
  • Decisions
  • 2 Associated documents
Ofgem has published its determination and notice of licence modification on National Grid Electricity Transmission’s Dorset AONB mitigation project under the RIIO1 provisions for enhancing pre-existing infrastructure.

  • Published: 23rd Aug 2017
  • Guidance
  • 1 Associated documents
Certification arrangements in Great Britain following amendments to the ownership unbundling requirements of the Gas Act 1986 and the Electricity Act 1989

  • Published: 16th Jul 2015
  • Decisions
  • 1 Associated documents
The Authority has approved CUSC Modification Proposal CMP223 WACM1.

  • Published: 24th Jun 2015
  • Decisions
  • 5 Associated documents
The Authority has approved the Network Access Policies for Scotland, England and Wales applicable to the SP Transmission, SHE Transmission plc and National Grid Transmission's electricity transmission licences.

  • Published: 16th Jun 2015
  • Reports and plans
  • 2 Associated documents
This report presents our assessment of the energy efficiency potential of the gas and electricity infrastructure in Great Britain.

  • Published: 13th Mar 2015
  • Decisions
  • 1 Associated documents
The Authority has approved Modification Proposal CMP238 ‘Application of Statement of Works process when a modification application is made'.

  • Published: 23rd Jan 2015
  • Closed: 20th Feb 2015
  • Consultations and responses
  • 3 Associated documents
This consultation is on our view that the revenue Scottish Power Transmission receives for the five years following construction remain at £19.366 million.

  • Published: 28th Jul 2014
  • Closed: 28th Aug 2014
  • Consultations and responses
  • 8 Associated documents
We propose to modify National Grid’s electricity transmission licence so that it must produce an electricity ten-year statement. This replaces the previous requirement for a seven year statement and offshore development information statement.

  • Published: 12th May 2014
  • Closed: 9th Jun 2014
  • Consultations and responses
  • 4 Associated documents
This letter sets out our proposal to modify Standard Licence Condition C11 to oblige National Grid Electricity Transmission plc (NGET) to produce an Electricity Ten Year Statement (ETYS).

  • Published: 17th Dec 2013
  • Closed: 21st Jan 2014
  • Consultations and responses
  • 8 Associated documents
Consultation on changes to National Grid Electricity Transmission plc’s electricity transmission licence to publish the Electricity Ten Year Statement (ETYS)