Electricity gets from power plants to electricity meters through transmission and distribution networks. This section explores the distribution component of the electricity supply chain.
What is an electricity distribution network?
Electricity distribution networks carry electricity from major grid supply points (where electricity transmission networks end) to industrial, commercial and residential customers.
Electricity gets to a distribution network substation at 275,000 or 400,000 volts. Transformers reduce voltage to 132,000. Voltage is further reduced to:
- 33,000 volts for heavy industry customers
- 11,000 volts for towns and villages and light industry customers
- 230 volts for homes, schools, shops and businesses
The electricity that comes out of your plug or lights your home (domestic usage) is set at 230 volts.
Electricity distribution networks are also the points of contact for power cuts, new connections to the grid, safety, and incident reporting. In a nutshell, electricity distribution networks are responsible for ensuring the light goes on and stays on if you have paid your bills.
Electricity distribution networks in brief
There are seven privately-owned electricity distribution companies in the United Kingdom covering 14 regions, as well as six independent distribution network operators (IDNOs).
Electricity North West
Electricity North West distributes power to 2.4 million customers in the North West of England through 13,000km of overhead lines, 44,000km of underground cables and 34,000 transformers.
Northern Ireland Electricity (NIE)
Northern Ireland Electricity delivers power to over 840,000 customers in Northern Ireland through 45,000km of overhead lines and underground cables, 75,000 pole-mounted transformers and 258 major substations.
Northern Powergrid distributes power to 3.9 million customers spread over 25,000 sq km in the North East of England, Yorkshire and northern Lincolnshire through 91,000km of overhead line and underground cables and 31,000 substations.
SP Energy Networks
SP Energy Networks distributes power to 3.5 million customers: 1.5 million customers in Merseyside, Cheshire, North Wales and North Shropshire and 2 million customers in Central and Southern Scotland. SP Energy Networks operates through 40,000km of overhead lines, 65,000km of underground cables and 30,000 substations.
SSE Power Distribution
SSE Power Distribution serves 3.7 customers in central Southern England and the north of Scotland through 130,000km of overhead line and underground cables and 106,000 cubstations.
UK Power Networks
UK Power Networks distributes electricity to 8.1 million customers in the East of England, the South East of England and London, an area of 30,000 sq km. Electricity distribution relies on 46,000km of overhead electricity lines, 138,000km of underground electricity cables, 118,000 transformers and 120,000 substations.
Western Power Distribution
Western Power Distribution serves 7.8 million customers in South Wales (WPD South Wales), South West England (WPD South West) and the Midlands (WPD Midlands), covering an area of 55,300 sq km through 220,000km of overhead lines and underground cables and 185,000 transformers.
Independent Distribution Network Operators (IDNOs)
Independent Distribution Network Operators provide distribution services in areas included in larger distribution networks. They do not have a specific geographical area and usually ensure electricity distribution from traditional electricity distribution areas to new constructions and developments. There are six IDNOs:
- Energetics Electricity
- ESP Electricity
- The Electricity Network Company
- UK Power Networks (IDNO)
- Utility Assets