CM0107 Code Administrator Consultation (1)

1 Public Code Administrator Consultation CM0107: Update for Centralised Strategic Network Plan Overview: Due to the upcoming introduction of the Centralised Strategic Network Plan (CSNP), several sections of the System Operator Transmission Owner Code (STC)/ System Technical Code Procedure (STCP) need to be changed as the references are becoming outdated, including the Electricity Ten Year Statement (ETYS), the Seven Year Statement (SYS), the Network Options Assessment (NOA) and the Offshore Development Information Statement (ODIS). Modification process & timetable Have 5 minutes? Read our Executive Summary Have 30 minutes? Read the full Code Administrator Consultation Have 45 minutes? Read the full Code Administrator Consultation and Annexes. Status summary: We are now consulting on this proposed change. This modification is expected to have a: Low Impact Any STC parties currently impacted by the ETYS, SYS, NOA or ODIS. Governance route Self-Governance modification to proceed to Code Administrator Consultation Who can I talk to about the change? Proposer: Thomas Goss Thomas.goss2@neso.energy 07522 998 916 Code Administrator Chair: stcteam@neso.energy How do I respond? Send your response proforma to stcteam@neso.energy by 5pm on 27 May 2026 Code Administrator Consultation 06 May 2026 - 27 May 2026 Draft Final Modification Report 16 June 2026 Final Modification Report 13 July 2026 Implementation 31 August 2026 1 4 5 6 7 Proposal Form 10 April 2026 2 Public Contents What is the issue? ............................................................................................................... 3 Why change? ...................................................................................................................... 3 What is the solution? .......................................................................................................... 4 Legal Text .............................................................................................................................. 4 What is the impact of this change?................................................................................. 5 When will this change take place? .................................................................................. 8 Implementation approach ............................................................................................... 8 Interactions ......................................................................................................................... 9 How to respond................................................................................................................... 9 Acronyms, key terms and reference material ............................................................. 10 Annexes.............................................................................................................................. 11 3 Public What is the issue? The introduction of the Centralised Strategic Network Plan (CSNP) requires that any older references are updated to previous Electricity Planning Data methodologies such as the Electricity Ten Year Statement (ETYS), which provides NESO’s view of the future of transmission requirements. The final iteration of the ETYS is currently scheduled for release in summer 2026. NESO’s licence has been changed to include the Centralised Strategic Network Plan (CSNP). The Grid Code and System Operator – Transmission Owner Code (STC) will need to have any references to previous iterations of planning documents removed, including the ETYS and remaining references to the previous Seven Year Statement (SYS), Network Options Assessment (NOA) or Offshore Development Information Statement (ODIS). As functions of the ETYS and the data it produces are still valid, where the CSNP is directly taking over the function this needs to be included, and the wording of the legal text amended to ensure continuity. Why change? As above, the CSNP is taking over the functions previously provided by the ETYS, which is being phased out in 2026 as per the mandate from Ofgem, including the data which is input to NESO and the reports being produced. Therefore, there is a need to ensure that the STC, STCPs, Grid Code and Connection and Use of System Code (CUSC) are amended in line with the new situation and do not contain references to redundant processes, which would cause confusion and uncertainty among stakeholders. The Proposer is progressing the changes in these codes in parallel with this request. The SYS, NOA and ODIS are already redundant at the time of writing and references need to be removed from the codes. 4 Public What is the solution? As the ETYS is being removed and many of the functions replaced by the CSNP there is a clear need for the Codes to keep pace with these changes. The references to the ETYS and SYS will need to come out as they will be redundant, and where the function is being taken over by the CSNP this will need to be added into the legal text. A list of STC references to ETYS and SYS has been compiled (see Appendix) and there will be potentially three scenarios: 1. References to ETYS/SYS where the function as described in the code section is being taken over in its entirety by the CSNP, and the reference can therefore simply be replaced (i.e. a straightforward replacement of ETYS for CSNP or similar). 2. References to ETYS/SYS where part of the function as described in the code section is being taken over by the CSNP but not all. The code section will need to be amended to ensure that the new reference to CSNP is correctly describing the functions it will fulfil, and any others are either removed or amended to describe the function and how they are being fulfilled. References to ETYS/SYS where the function is either completely redundant or is only a description or confirmation of the ETYS/SYS. For example, this would include mentions in a definitions section, or a passage which is being removed from the Licence and can safely be taken out of the Code without needing further modification. Legal Text As per the above sections there will be several different changes to the existing STC legal text depending on how the change from ETYS to CSNP affect the wording, and other than the three types of changes there is no standard pattern. Documents outlining the specific proposed changes for each reference to ETYS, SYS, NOA and ODIS are included as Annex 02. The specific sections of the STC affected are as follows: • Section D Planning Co-ordination, Part 1 Introduction 1.1.3, 5 Public • Section D Planning Co-ordination, Part 1, 4 Electricity Ten Year Statement: Entire section, • Section H - Disputes: Section 4.3.12, • Section J – Interpretation and Definitions • Schedule 3 2.1 (j) and (k), 2.1.6 (b, ii), 3.7 • Schedule 8 1.3.3, STCP 16-1 Appendix D 'Abbreviations and Definitions’, • Schedule 8, TO Construction offer 1.1.3.2 (c), • Schedule 9 A: 2.62, B: 2.4, Contents Headings, • Schedule 9 C: 1.1, 2.7.2, Appendix For reference, a future STCP modification will be raised and is likely to make changes to the below STCPs. • STCP 03-1 Issue 008 Post Event Analysis and Reporting • STCP 18-1 Issue 016 Page 34, Stage 3, • STCP 20-1 Issue 007 Electricity Ten Year Statement: (Entire document), • STCP 21-1 Issue 006 Network Options Assessment, • STCP 22-1 Issue 006 Production of Models for GB System Planning There will also need to be code modifications raised for the Grid Code, STCPs and CUSC as these will also be impacted by the same changes to the ETYS. What is the impact of this change? This modification will impact any current STC parties who use or are involved with ETYS, i.e. anyone who provides data input to the ETYS process, and those who use the outputs of the ETYS. Ofgem decision states that the next iteration of the ETYS report (summer 2026) will be the final one. However, NESO’s licence has already been updated regarding the requirements for CSNP. The Proposer will be updating the codes to ensure that the information is submitted in accordance with the new processes. 6 Public Proposer’s assessment against STC Objectives Relevant Objective Identified impact (a) efficient discharge of the obligations imposed upon Transmission Licensees by Transmission Licences and the Electricity Act 1989; Positive This modification ensures that we have continuity in terms of the data gained from the affected parties. The expectations from customers will not be changing except for the new name, location and timing of the data they already provide. (b) efficient discharge of the obligations imposed upon the licensee by the Electricity System Operator licence, the Energy Act 2023 and Electricity Act 1989; Positive See (a), removes any ambiguity between the requirements of all parties. (c) development, maintenance, and operation of an efficient, economical, and coordinated system of electricity transmission; Positive Ensuring that the references in the STC are up to date and redundancy is removed, ensures a correct flow of information and facilitating more effective future planning operations. (d) facilitating effective competition in the generation and supply of electricity, and (so far as consistent therewith) facilitating such competition in the distribution of electricity; Positive By ensuring the codes refer to the correct name for the published network planning data, Generators are better directed and can research the market better, facilitating more effective competition. (e) protection of the security and quality of supply and safe operation Positive The STC is, by this modification, kept up to date with the latest NESO 7 Public of the National Electricity Transmission System insofar as it relates to interactions between Transmission Licensees and the licensee; Independent System Operator and Planner (ISOP) licence conditions C12/C17 regarding the production of a Centralised Strategic Network Plan in future. (f) promotion of good industry practice and efficiency in the implementation and administration of the arrangements described in the STC; Positive See (e) (g) facilitation of access to the National Electricity Transmission System for generation not yet connected to the National Electricity Transmission System or Distribution System; and Neutral (h) compliance with the Electricity Regulation and any Relevant Legally Binding Decisions of the European Commission and/or the Agency. Neutral * See Electricity System Operator Licence Proposer’s assessment of the impact of the modification on the stakeholder / consumer benefit categories Stakeholder / consumer benefit categories Identified impact Improved safety and reliability of the system Neutral Lower bills than would otherwise be the case Neutral 8 Public Benefits for society as a whole Positive The investment NESO is putting into the CSNP project will not only take over the functions which the ETYS provided but expand them as well. The new system will better utilise the data in terms of whole system analysis and future planning, ensuring that the network is as efficient and cost-effective as possible. Reduced environmental damage Neutral As the data that users send to NESO will be used as part of the overall CSNP process, analysis produced will better mitigate against environmental damage thanks to the whole system view the new process is conducting. Improved quality of service Positive See ‘Benefits for Society as a whole’. When will this change take place? Implementation date: 31 August 2026 Date decision required by: Mid-August 2026 Implementation approach The Proposer has been discussing the implementation of the necessary STC changes with the Transmission Owners (TOs) since the middle of 2025, and the draft of the changes has since been shared with them as well as approaching the STC Panel. Changes have also been discussed with Ofgem during this period. We have also been receiving comments in return over the last 6 months from the TOs, and the proposal has been raised in the Joint Planning Committee (JPC) 9 Public sessions and their sub-groups, as well as the STC Panel in February 2026 in readiness for the full Proposal in the April Panel. Interactions ☒Grid Code ☐BSC ☒CUSC ☐SQSS ☒European Network Codes Other modifications ☐Other Alongside this STC modification we are also raising one for the Grid Code changes as well as in the CUSC, and we will be raising STCP changes as a Consequential modification. How to respond Code Administrator Consultation questions • Please provide your assessment for the proposed solution against the Applicable Objectives versus the current baseline. • Do you support the proposed implementation approach? • Do you have any other comments? Views are invited on the proposals outlined in this consultation, which should be received by 5pm on 27 May 2026. Please send your response to stcteam@neso.energy using the response pro-forma which can be found on the modification page. If you wish to submit a confidential response, mark the relevant box on your consultation proforma. Confidential responses will be disclosed to the Authority in full but, unless agreed otherwise, will not be shared with the Panel or the industry and may therefore not influence the debate to the same extent as a non-confidential response. 10 Public Acronyms, key terms and reference material Acronym / key term Meaning BSC Balancing and Settlement Code CM Code Modification CSNP Centralised Strategic Network Plan CUSC Connection and Use of System Code ETYS Electricity Ten Year Statement ISOP Independent System Operator and Planner JPC Joint Planning Committee NESO National Energy System Operator NOA Network Options Assessment ODIS Offshore Development Information Statement SQSS Security and Quality of Supply Standards STC System Operator Transmission Owner Code STCP System Technical Code Procedure SYS Seven Year Statement TO Transmission Owner Reference material • ETYS-CSNP STC Legal Text changes proposal v1.xlsx • Centralised Strategic Network Plan (CSNP) | National Energy System Operator 11 Public • Electricity Ten Year Statement (ETYS) | National Energy System Operator Annexes Annex Information Annex 01 CM0107 Proposal Form Annex 02 CM0107 Legal Text