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Electricity Ten Year Statement (ETYS)

Planning for the future.

Electricity in Great Britain is changing rapidly with more renewable generation from an increased number of sources. The ETYS provides our view of how this will impact the National Electricity Transmission System (NETS) for the next ten years. 

This year we have take a new approach to the ETYS and have published the analysis in a series of interactive webpages. We are keen to hear your thoughts on the new format!


Head of Networks, Julian Leslie highlights the key messages from this year’s report.

What is the ETYS?

Each year we publish the ETYS to share our latest assessment of the future requirements of Great Britain’s electricity transmission system. It highlights areas where there are uncertain future power flows and network reinforcements are needed. This creates opportunities for other industry participants to get involved by proposing innovative ideas and solutions that help us to further develop the electricity transmission system.  

How does it fit with our other publications?

We use the data from our Future Energy Scenarios (FES) to identify the points on the transmission network where there is going to be network congestion. We determine network transfer capacity in the region and overlay this on the power flows expected over the next 10 years, to identify what reinforcements are needed to deliver a safe and reliable supply of electricity to consumers. Once we know what the network requirements are, we invite stakeholders to propose solutions that will help us to meet these requirements. These proposals are assessed through our Network Options Assessment (NOA) process, where the most economic and efficient solutions are given a recommendation to proceed, and others told to hold or stop.

This publication cycle is key to our network planning process. The ESO’s ambition is to be able to operate a zero-carbon electricity system by 2025. This means if the market provides us with electricity solely generated from zero-carbon sources, we can run the system without needing to use any extra services that emit carbon. Achieving zero-carbon by 2025 is a big step forward in the UK’s journey to net-zero by 2050. We are keen to work closely with industry to develop solutions to network challenges so that we can operate a greener, cleaner electricity system.

Summary of key messages

  • Wind generation across the Scottish electricity networks will continue to increase over the next ten years, meaning that network reinforcements will need to be made to the north-to-south transmission network. We have identified that this will require a doubling of the north to south transfer requirements.
  • An increase in wind generation in Scotland, added to interconnection in the North of England would mean network reinforcements are needed in the Midlands to accommodate increased power flows.
  • We anticipate more interconnectors will be built in the south and east regions of GB. If more interconnectors export to Europe at the same time as significant wind output, there will be high power flows across the whole transmission network from north to south. This means more network reinforcements are required in the London and South England areas.
  • We are forecasting more generation coming from offshore wind on the east coast connecting to East Anglia. This would increase the need for reinforcement in this region of the network.
  • We’ve created a new chapter this year that focusses on a year-round assessment of requirements. This is because energy sources such as wind and solar, combined with new technologies such as electric vehicles, energy storage and heat pumps are increasing. This change in generation and demand patterns makes planning for the right network developments much more complex. Previously we only looked at winter peak conditions. Looking at requirements throughout the year will provide more clarity on the likely flows on the system over the next ten years and identify where more reinforcements will be needed.

This report is another example of the changes needed to deliver a zero-carbon power grid. We will build on this analysis and work with industry to inform the transformation of Great Britain’s electricity system and continue to deliver reliable, affordable energy for consumers.

You can read the full version of the ETYS here and find out how you can get involved.