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), now known as  Department for Energy Security and Net Zero (DESNZ), 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 obligates the Electricity System Operator (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. 

The ESO is obligated to adhere strictly to any directive related to Electricity System Restoration from the Department for Energy Security and Net Zero (DESNZ).

Following the ESRS directive, the ESO has put into motion several actions geared towards attaining full compliance by the deadline of 31st December 2026. Following the ESRS directive, the ESO has put into motion several actions geared towards attaining full compliance by the deadline of 31st December 2026. The actions vary from modifying the regulatory frameworks to accommodate ESRS, to revising the restoration strategy from a top-down restoration approach into a holistic strategy, which incorporates both top-down and bottom-up restoration approaches.  

The timeline below gives a vivid view of what has been done and what we intend to do prior to 31st December 2026. 

The ESO is committed to investing in activities that lead, organise and build consensus with government, regulators and the industry, to drive improvements to system restoration strategy.

Working groups

Non-code working groups

The Technology and Locational Diversity working group assessed how different technologies could contribute to faster restoration times and an enduring supply of demand (expected to be two to five days after a Total System Shutdown).

Working group documents

ESRS - Technology and Locational Diversity - Terms of Reference

ESRS - Technology and Locational Diversity WG report 

The Future Networks working group identified 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

ESRS - Future Networks WG report 

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

Working group documents

ESRS - Markets and Funding Mechanism - Terms of Reference

ESRS - Markets and Funding Mechanism report 

The Regulatory Frameworks working group delivered 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

ESRS - Regulatory Framework output 

The Compliance Activities working group defined the 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

Assurance Activities Workgroup report 

Appendix A Assurance Activities Framework 

The Communication Infrastructure working group developed an understanding of the role of communications in restoration and the necessity of a secure and resilient communications infrastructure to ESRS.

Working group documents

ESRS - Communication Infrastructure - Terms of Reference

ESRS - Communication Infrastructure report 

The Modelling and Restoration Tool working group developed 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 - Modelling and Restoration report 

We have consulted on the services the ESO should establish and/or procure to comply with the new 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 2021 and sought responses from all industry stakeholders. 

Consultation documents

ESRS Implementation Consultation

ESRS Consultation Responses

The consultation responses served as the basis for the formation of the GC0156 working groups.

GC0156 subgroups

Following the work done by the seven Non-Code Working Groups, four GC0156 Code Working Groups were constituted to focus on ESRS requirements under Assurance Activities, Communication infrastructure, Future Networks and Market and funding mechanisms. The final reports of the workgroups are presented below.

GC0156 subgroup reports

The Assurance Activities subgroup identified assurance activities required under ESRS and suggested their implementation routes as well as proposing relevant changes to Codes

Assurance Activities subgroup report 

The Communication Infrastructure subgroup proposed changes to the telecommunication requirements for Network Operators, TOs, OFTOs, CATOs, DNOs and Restoration Contractors and other relevant parties. These changes will enable communication to occur during restoration to guarantee that parties are informed of what steps to take. It also proposed the implementation of ICCP links or equivalent between ESO and all DNOs for Network visibility. 

Communication Infrastructure subgroup report 

The Future Networks subgroup proposed solution to challenges that may arise from the use of Distributed Energy Resources (DERs) as Restoration Contractors. The working group also looked the changes required on the NETs to be ESRS compliant.

Future Networks subgroup report 

The Markets and Funding Mechanisms subgroup proposed funding and compensation mechanisms which will be used by various stakeholders such as Anchor and Top-Up Restoration Contractors, other CUSC parties, Other DERs (Non-CUSC and Non-Contracted), Interconnectors, Non-restoration Users and All Network Owners (TOs, OFTOs, CATOs, DNOs). 

Market and Funding Mechanisms subgroup report 

On 21 November 2022, the ESO issued an industry wide consultation on the Grid Code modifications proposed by the GC0156 working group to accommodate ESRS. 

View the consultation documents

CMP398 guidance note