Way forward

The ETYS is the ESO’s view of how the future transmission system requirements will be met. Currently, this focuses mainly on bulk power transfer requirements, particularly during winter-peak conditions.

As operation of the National Electricity Transmission System (NETS) becomes increasingly complex, we need new ways to identify weak points to address in the network planning process. This will involve the use of innovative analysis techniques, such as our work on year-round probabilistic analysis, and looking at the NOA pathfinders to see how we can better address both voltage and stability issues. This could lead to more informed network investment and operational planning decisions.

Year-round probabilistic analysis

We continue to develop our probabilistic analysis tools to analyse year-round system conditions. This will allow us to assess more snapshots and identify system needs that could arise from a range of generation and demand conditions.

This year we committed in our ETYS consultation to present our probabilistic tool developments in a separate publication. This will allow us to focus more on the probabilistic methodology and its potential use outside of our license requirements for the ETYS publication and allow the ETYS to focus on communicating system needs.

We will look at year-round network performance and requirements and demonstrate the new functionality added to our tool during the past year. The report will give more detailed insight into our analysis and updates on related innovation projects. We will also present our findings alongside a clear vision for their use cases and potential integration within the ETYS and NOA processes.

We intend to publish this new document in the first quarter of 2022.

NOA Pathfinder projects

The ETYS is looking to expand its view of system needs, informed by the NOA pathfinders. The road to determining the future network capability requirements and opportunities needs to be constantly refined and developed.

One of the ways we do this is through the NOA pathfinders.

These investigate specific network requirements and open the network development to a wider range of participants, both regionally and nationally.

The future development of the ETYS and NOA will be shaped by the NOA pathfinder projects which aim to resolve additional challenges related to thermal, high voltage and stability constraints.

In June we published our annual voltage screening report identifying areas that could have future high voltage system needs. We are now carrying out more detailed analysis to quantify the requirements.

Pathfinders already underway


NOA High Voltage Pathfinder

Finding solutions to regional high voltage issues.


NOA Stability Pathfinder

Addressing our immediate needs of national inertia, and local short circuit level needs in Scotland.


NOA Constraint Management Pathfinder

Resolving network constraint issues and lowering balancing costs.

Stakeholder engagement

The ETYS and NOA publications are continually evolving to meet our ambitions set out in the ESO’s RIIO-2 Business Plan. As the documents expand to a wider audience, we hope you will help shape them to become even more valuable for you and others to use.

We would like to hear your views on how we should shape the ETYS and NOA publications to make them more valuable. Our draft timetable for ETYS and NOA 2021 and our 2022 stakeholder activities is shown below.

We welcome your views on this year’s ETYS, what works well and what we need to improve. Our stakeholder activities are a great way for us to:

  • Learn more about the views and opinions of all our stakeholders

  • Provide constructive feedback and debate

  • Create open, two-way communication about assumptions, analyses and findings

  • Let stakeholders know how we have used their feedback

There are many ways you can let us have your feedback, including:

  • Taking part in our written ETYS Form consultation (planned for April 2022)

  • Consultation events as part of our customer seminars

  • Industry engagement events e.g. operational forums, etc

  • Email [email protected]

  • Stakeholder meetings

Discover more about ETYS

ETYS and the Network Planning Process

Learn about how we prepare the ETYS and how it fits with our network planning process.

Electricity transmission network requirements

You can discover more about the various regions of the transmission system and their capabilities.

Way forward

Read how we are going to improve the ETYS and how you can get involved.

ETYS documents

Get to the appendices, glossary and other helpful contact information.