Developing our future electricity network
About future electricity networks
The electricity grid is the national infrastructure that allows us to transport power from where it is generated to the end user (see diagram). It consists of a transmission network that moves electricity over long distances at high voltages, and a number of lower voltage regional distribution networks that feed electricity into homes and businesses. It is a fundamental asset and vital to the UK’s economic and national security.
DECC’s Aim and Objectives
DECC's work on future electricity networks spans the whole of the GB systems: onshore, offshore, interconnection, transmission and distribution.
Our aim is to ensure the timely, cost-effective and reliable connection of electricity generation to demand, to support a low carbon, secure and affordable GB electricity system.
As such, our objectives for future electricity networks are to:
- Maintain GB's electricity network reliability, in order to facilitate economic and social prosperity
- Ensure new generation (including renewables, nuclear and fossil fuels) and new demand (including electric vehicles and heat pumps) receive timely and affordable connection to the network
- Networks are cost-effective, due to effective regulation, competitive pressure and the use of smarter technology
The current British Electricity Network
Electricity generators, including those generating electricity from renewable energy sources, normally connect to either the transmission grid or the distribution networks.
The GB transmission grid consists of around 25,000 circuit kilometres of high voltage overhead lines (the national grid) and 800,000 circuit kilometres of overhead lines and underground cables (the regional distribution networks).
The difference between these grids is normally the voltage:
- Transmission grid voltages are normally 275 kilovolts and above in England and Wales; (132 kilovolts in Scotland and offshore).
- Distribution network voltage levels are normally 11 kilovolts, 33 kilovolts, 66 kilovolts and 132 kilovolts (except for offshore wind and Scotland).
- National Grid owns the England and Wales transmission system. Scottish Power Transmission (SPT) and Scottish Hydro Electric Transmission Limited (SHETL) each own part of the transmission system in Scotland. As transmission owners, these companies are responsible for building and maintaining safe and efficient networks, and are regulated by Ofgem. The grid in Northern Ireland is owned by Northern Ireland Electricity.
As the National Electricity System (NETS) system operator, National Grid is also responsible for overseeing and managing the flow of electricity across the whole of the GB transmission network. This includes the elements owned and operated by SPT and SHETL and the offshore transmission connections. National Grid also co-ordinates connection offers to new generators. The system operator for Northern Ireland, SONI, manages the electricity system and flows in Northern Ireland.
There are 14 licensed distribution network operators (DNOs) each responsible for a distribution service area. The 14 DNOs are owned by six different groups.