What is the ESO and what does it do?

As the electricity system operator for Great Britain (GB), we move electricity safely, reliably and efficiently through the system.

We don’t generate or sell electricity and we are not responsible for the infrastructure, for example the pylons and cables, needed to move electricity around. We are only here to ensure homes and businesses have the power they need whenever it’s needed. It might sound simple but it’s a complicated job to deliver electricity every single minute of every single day, making sure that demand and supply are always balanced.

It can be helpful to think of GB’s electricity system in terms of our road network. National Grid, a legally separate company to the ESO, owns the motorways, or the transmission network. The ESO uses these motorways to run high voltage electricity through the system until it gets to the B roads, which are privately-owned local distribution networks. From there smaller operators - Distribution Network Operators, or DNOs – reduce the voltage and take electricity to peoples’ doors. Connected to these networks are privately-owned power stations, which are separate from National Grid. They generate and feed electricity into the network.

GB’s electricity runs through over 4,500 miles of overhead cable and 870 miles of underground cables. And when the UK does not have enough of its own energy, we import it from different countries including the Netherlands and France. We export too, when we have too much.

This video explains the role of the ESO
This infographic shows GB’s electricity ecosystem and the ESO’s role within it

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Why is the ESO a legally separate company to National Grid plc?

In 2017 Ofgem, the Department for Business, Energy and Industrial Strategy (BEIS) and National Grid plc agreed to create a legally separate business – National Grid Electricity System Operator (ESO) – within the National Grid Group. ESO became a separate entity within the group on 1 April 2019.

Separating the ESO business from National Grid Electricity Transmission provides transparency in our decision-making, and gives confidence that everything we do will promote competition and is ultimately for the benefit of consumers and industry stakeholders.

This map shows all of Great Britain's power stations by type of plant

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