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What we do

We own and maintain the electricity transmission network in England and Wales

What we do

We own and maintain the electricity transmission network in England and Wales

Our Transmission network consists of overhead lines, underground cables and substations. It operates at 400,000, 275,000 and 132,000 volts. Directly connected to our network are 45 power stations, 12 Distribution networks,which connect to people’s homes and businesses and a few large industrial customers. The transmission system is also connected to three interconnectors to other countries.  

We are regulated by Ofgem through a framework known as RIIO, and under this framework we charge our customers for using our network. The current regulatory period is known as RIIO-T1 and runs from 2013 to 2021. RIIO 2 is likely to run from 2021 to 2026.

We don’t generate electricity or own or operate UK Electricity Distribution networks, and we don’t sell electricity to household consumers in the UK.

The Electricity Transmission business in National Grid will soon be separate from the Electricity System Operator business. 

We want to make sure that the needs of our stakeholders are the key input into our future plans.


The Transmission network we know today was built in the 1950s and 1960s, and since then it has developed to meet the country’s energy needs – allowing large-scale sources of generation to connect into the network, acting as the connection point for interconnectors to/from other countries, and allowing energy to be supplied to areas of high demand from areas where there are large levels of generation.

But the energy industry in Great Britain is changing rapidly. More local solar projects, more wind farms, households moving to heat-pumps, and an increase in the number of electric vehicles on our roads all have an impact on what the Transmission network needs to provide. And there’s still a need for large-scale ‘steady’ sources of generation to fill the gaps when the sun doesn’t shine or the wind doesn’t blow.

There are many ways in which the future could unfold and it’s dependent on many factors, including new technologies, political priorities and the health of our economy. We believe that the Transmission network will play a vital role in helping the country deal with this uncertainty.

It will still need to move energy over long distances from a variety of sources to ensure the country has a reliable supply of electricity, and by operating at higher voltages (which lose less energy during transport), it can do this more cheaply than some other networks. It will also ensure that energy costs are as low as possible by giving consumers access to markets that otherwise would not have been the case, including those in other countries.

We know that some of our stakeholders might not agree though, so we’d love to hear your views on this.

Did you know that 27% of the electricity generation on the system today connects to the regional distribution networks or behind the meter?

Or that, in the Electricity System Operator's latest Future Energy Scenarios, the Community Renewables scenario has distributed generation exceeding 50% by 2034?

To find out more, read Senior Strategy Analyst Chris Harris’ second thought piece where he looks forward to the role electricity transmission can play in the future. Read the full article here.