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Electricity System Restoration Standard

A successful path to zero carbon necessitates changes to our existing Electricity System Restoration preparation arrangements. In particular, investments in services, new technologies, frameworks, operational tools and methods will be required to accommodate the transition efficiently.  

The Department of Business, Energy and Industrial Strategy (BEIS) released a Policy Statement setting out the need to strengthen the current regulatory framework by introducing a legally binding target for the restoration of electricity supplies in the event of a nationwide or partial power outage on the national electricity system – a new Electricity System Restoration Standard (ESRS).  

This new ESRS requires the ESO to have sufficient capability and arrangements in place to restore 100% of Great Britain’s electricity demand within five days. This should also be implemented regionally, with an interim target of 60% of regional demand to be restored within 24 hours. The ESO must ensure that everything is in place to comply with this standard by no later than 31st December 2026. 

In order to implement the new standard and meet the agreed deadline, the ESO will need to review its restoration plans and is envisaging, among others things, the need to procure additional restoration services from traditional and non-traditional sources. 

We have established industry working groups to identify and implement the changes that are required to resolve these issues and published a consultation seeking industry views on the impact of meeting the requirements of the ESRS.

ESRS Timeline

Working groups

Technology and Locational Diversity

Our Restoration (Black Start) tenders have been developed to encourage participation from a wider technology range of providers and increase competition. To meet the Electricity System Restoration Standard (ESRS) we will need a wider range of technologies across the different regions of GB to provide restoration service.

The Technology and Locational Diversity working group will assess how different technologies could contribute to faster restoration times and an enduring supply of demand (expected to be two to five days after a National Power Outage).

Working group documents

ESRS - Technology and Locational Diversity - Terms of Reference

Future Networks

A greater level of renewable energy is connecting across GB and electricity networks are developing to accommodate these changes in the generation mix. These networks will need to adapt further to meet the requirements of the Electricity System Restoration Standard (ESRS).

Additional providers are expected to be contracted to provide restoration services, and the networks they connect to will need to ensure that they can meet the technical requirements to enable them to provide that service in a National Power Outage.

The Future Networks working group will identify the development needs of networks to accommodate the changes in the generation mix across GB required to implement the ESRS.

Working group documents

ESRS - Future Networks - Terms of Reference

Markets and Funding Mechanisms

Procurement of Restoration (Black Start) services is defined in the Black Start Strategy and Procurement Methodology, which will be replaced by the new Electricity System Restoration (ESR) Assurance Framework to be published in April 2022.

The principles of this procurement methodology are:

  • A clear and transparent requirement.

  • Enabling competition, where appropriate.

  • Reducing and removing barriers to entry to enable broader participation.

In order to meet the requirements of the Electricity System Restoration Standard (ESRS) we want to encourage a diverse mix of technologies and locations to provide restoration services. We also need to ensure that costs are optimised and the services are procured efficiently, which is best done by procuring these services using competitive markets.

The ESO believes that efficient costs for transmission and distribution network changes in direct support of ESRS should be recouped through their respective price controls, and that network companies should have appropriate terms in their licence to enable recovery of costs associated with implementation of the ESRS.

The Markets and Funding Mechanism working group will understand how to further remove market and/or funding barriers (real or perceived) and assist in the development of agile solutions for restoration.

Please also note we have published our consultation on the Assurance Framework as part of the ESO Licence condition. This consultation ran for 30 days like the ESRS consultation and closed on the 17 December 2021.
Please send all responses to [email protected]

Working group documents

ESRS - Markets and Funding Mechanism - Terms of Reference

Regulatory Frameworks

The ESO are implementing changes to relevant codes to align with requirements of the Network Code on Emergency & Restoration (NCER) and to meet the recommendations from our Distributed Restart project.

We anticipate that further changes to codes will be identified and proposed to implement the Electricity System Restoration Standard (ESRS). The ESO intends to have all code modifications in place by September 2023 at the latest to allow required changes to be implemented by end of December 2026.

The Regulatory Frameworks working group will deliver the changes needed in the relevant industry codes that will enable the implementation of a fit-for-purpose framework for the ESRS.

Working group documents

ESRS - Regulatory Frameworks - Terms of Reference

Compliance Activities

The ESO will need to produce and consult on an Electricity System Restoration (ESR) Assurance Framework. This Framework will need to demonstrate that the ESO has a credible plan for monitoring its compliance with the Electricity System Restoration Standard (ESRS) at all times. Regular testing is already performed for existing Restoration Service Providers including restoration capability tests, voice system tests, control system resilience tests, cyber security tests, auxiliary power sources test and power island synchronisers tests.

However, in order to provide assurance that we have met the requirements of the ESRS, there is an increased need for a baseline level of testing and exercising of restoration capabilities, across the power sector.

The Compliance Activities working group will define mandatory and optional compliance activities per stakeholder group, and define the framework that will allow monitoring of industry performance against the mandatory compliance activities.

Working group documents

ESRS - Compliance Activities - Terms of Reference

Communication Infrastructure

Effective and efficient communication is key to enabling the restoration of the electricity network following a National Power Outage. We will need end-to-end operational telecommunication between all parties involved in system restoration to be available while supplies are restored (up to five days). This will enable exchange of data, supervisory control, provide situational awareness and voice communication between restoration participants.

The Distributed Restart project has identified several changes to systems, tools and data that need to be made to enable restoration from distributed energy resources including functional specification for resilient and cyber secure telecoms. The findings from this project will form some of the inputs for this working group.

The Communication Infrastructure working group will develop an understanding of the role of communications in restoration, and enable the delivery of a secure and resilient communications infrastructure.

Working group documents

ESRS - Communication Infrastructure - Terms of Reference

Modelling and Restoration Tool

The ESO will require the ability to model the restoration capability to provide the appropriate level of confidence to industry parties that the outcomes of the model are a fair representation of the restoration times in GB.

We currently use a probabilistic tool which was developed by the ESO on behalf of wider industry owing to our central role and access to relevant sensitive information. The results have been determined through Monte-Carlo simulation techniques to explore the range of possible outcomes for a set of central circumstances

The Modelling and Restoration Tool working group will develop a framework that will give relevant industry parties confidence that the restoration model(s) outputs are a fair representation of restoration times in GB.

Working group documents

ESRS - Modelling and Restoration Tool - Terms of Reference

ESRS Implementation Consultation

Please be aware we have published our consultation on the implementation of the ESRS (Electricity System Restoration Standard).

We have consulted on the services the Electricity System Operator (ESO) should establish and/or procure to comply with the new Electricity System Restoration Standard (ESRS), and the issues each sector of the electricity industry expect to face in providing, or facilitating the provision of, these services.

This consultation closed on 17 December and sought responses from all industry stakeholders. These will feed into our industry working groups who will be proposing changes to industry frameworks to support implementation of the ESRS and must come into effect by September 2023 at the latest.

Consultation documents

ESRS Implementation Consultation

ESRS Consultation Responses