GC0164 Final Modification Report (2)

1 Public Final Modification Report GC0164: Simplification of Operating Code No.2 Overview: This modification seeks to help Users to clearly identify their obligations under Operating Code No.2 (OC2) by making it more accessible, easy to navigate and understand. This is the first modification resulting from the Alignment, Simplification and Rationalisation Workstream (ASRW) of the Digitalised Whole System Technical Code project. Modification process & timetable Have 30 minutes? Read our Executive summary Have 120 minutes? Read the full Final Modification Report Have 210 minutes? Read the full Final Modification Report and Annexes Status summary: This report has been submitted to the Authority for them to decide whether this change should happen. Panel recommendation: The Panel recommended unanimously that the original better facilitated the Applicable Grid Code Objectives. This modification is expected to have a: Low impact on Restoration Service Providers, Generators, Interconnector Owners, Transmission Owners, Non-Embedded Customers, Network Operators and The National Energy System Operator (NESO) Modification drivers: Efficiency and Transparency Governance route Standard Governance modification assessed by a Workgroup Who can I talk to about the change? Proposer: Frank Kasibante, NESO frank.kasibante1@neso.energy Code Administrator Chair: Deborah Spencer deborah.spencer@neso.energy Proposal Form 12 October 2023 Implementation 10 BD after Decision Second Draft Final Modification Report 15 April 2026 Workgroup Consultation 07 June 2024 - 08 July 2024 Workgroup Report 20 November 2024 Second Code Administrator Consultation 27 February 2026 - 27 March 2026 Final Modification Report 05 May 2026 1 2 3 4 6 5 7 2 Public Contents Executive Summary ................................................................................................................................................................................ 3 What is the issue? .................................................................................................................................................................................... 4 What is the defect the Proposer believes this modification will address? .......................................................... 4 Why change? .............................................................................................................................................................................................. 4 What is the solution? .............................................................................................................................................................................. 5 What is the impact of this change? ............................................................................................................................................. 8 Proposer’s assessment against Grid Code Objectives .................................................................................................... 8 Proposer’s assessment of the impact of the modification on the stakeholder / consumer benefit categories .................................................................................................................................................................................................... 10 Legal text ........................................................................................................................................................................................................ 11 Workgroup considerations ................................................................................................................................................................ 12 Workgroup Discussion ahead of the Workgroup Consultation ................................................................................. 12 Workgroup Consultation Summary ............................................................................................................................................ 14 Post Workgroup Consultation Discussion ................................................................................................................................ 16 Terms of Reference Overview .......................................................................................................................................................... 16 First Workgroup Vote ............................................................................................................................................................................. 18 First Code Administrator Consultation Summary .............................................................................................................. 19 First Panel recommendation vote ............................................................................................................................................... 20 Workgroup Discussions following Panel Send Back ......................................................................................................... 20 Panel Send Back of the Second Code Administration Consultation ..................................................................... 22 Workgroup Discussions following Panel Send Back ......................................................................................................... 23 Second Code Administrator Consultation Summary ..................................................................................................... 24 Panel Recommendation vote ........................................................................................................................................................ 26 When will this change take place? ...........................................................................................................................................30 Acronyms, key terms and reference material ...................................................................................................................... 31 Annexes ......................................................................................................................................................................................................... 31 3 Public Executive Summary This modification seeks to simplify the text in Operating Code 2 (OC2) within the Grid Code to help Users identify and understand the obligations placed upon them. What is the issue? OC2 within the Grid Code is widely agreed to be overly complex, poorly structured, and difficult for Users to navigate. The text makes it difficult for Users to understand and comply with current processes or understand their own and others’ obligations. It also contains Appendices which are more logically located in other sections of the Grid Code. What is the solution and when will it come into effect? Proposer’s solution: To simplify the text in OC2 ensuring any amendmaents have no material impact on any User or the NESO. Implementation date: 10 Business Days following the Authority decision. What is the impact if this change is made? Ease of use of OC2 which will help Users understand and implement their obligations correctly and for the NESO to administer the Grid Code. It is believed also, that simplifying the text could encourage potential market entrants and innovative industry entrants. Workgroup conclusions: The Workgroup concluded unanimously that the Original better facilitated the Applicable Objectives than the Baseline. Code Administrator Consultation: The Code Administrator Consultation received 1 non-confidential response. Panel recommendation: Panel met on 23 April 2026 to carry out their recommendation vote. 4 Public Interactions This modification has an interaction with the Electricity Balancing Regulation Article 18 Terms and Conditions due to changes to the Data Registration Code. There is also an interaction with 1GC0183, which makes changes to Operating Code 2. What is the issue? What is the defect the Proposer believes this modification will address? The Grid Code2 is widely agreed to be overly complex, poorly structured, difficult to navigate and complicated for Users to understand the obligations placed upon them. The Digitalised Whole System Technical Code (dWSTC) project3 was set up to address some of the challenges of using the technical codes and is an opportunity to support the Energy Codes Reform (ECR) objective of code simplification. The Operational Planning and Data Provision (OC2) is one section within the Grid Code where the complexity of the text could make it difficult for the reader to understand and comply with current processes or understand their own and others’ obligations. It also contains Appendices which are more logically located in other sections of the Grid Code. Why change? The dWSTC project was established to create an accessible and agile code system which is easier for both new and established market participants to access, understand and navigate than the current codes. The intention is to 1 GC0183 Generator and Interconnector Availability During a Severe Space Weather Event 2 The Grid Code 3 Digitalised Whole System Technical Code 5 Public achieve this by removing inefficiencies in operating and maintaining the codes and encouraging new industry entrants. This will also set up the codes for further development to match the current pace of change in the industry. The NESO received feedback from some parts of the industry, indicating that simplification of codes would deliver benefits to their organisations. OC2 has been selected as an initial focus for simplification by the Alignment, Simplification & Rationalisation Workstream (ASRW) because it is both somewhat outdated and not among the most frequently utilised sections of the Code. This provides an ideal opportunity to test the application of simplification principles, such as streamlining and clarifying text, incorporating diagrams, adopting plain English, eliminating unnecessary duplication, refining definitions, and ensuring legal enforceability within the constraints of current resources. Moreover, simplifying OC2 is expected to enhance both existing and prospective Users’ understanding of its requirements and provisions. The GC0164 Workgroup established by the Grid Code Review Panel has developed the improvements proposed by the ASRW which are presented in this second Code Administrator Consultation for consideration. The proposal represents the first attempt to incorporate Grid Code simplifications flowing from the dWSTC project. What is the solution? The modification is not intended to change any obligations placed on Users in the current OC2 text. The primary aim is to make OC2 easier to understand and apply. The process followed within this modification might prove helpful while considering streamlining and improving other codes. As part of the process of simplifying and rationalising OC2, extensive use was made of diagrams, avoiding duplication and using plain English. In addition, the opportunity was taken to move some sections of legal text out of OC2 and place them into other sections of the code where this was deemed as more appropriate. For example, the section on Generator Performance Charts has been moved from OC2 Appendix 1 into the 6 Public Planning Code and any changes to definitions used in OC2 have been applied to the Glossary and Definitions. It is important here to note that where changes have been made to other sections of the Grid Code (e.g., the Planning Code and Glossary and Definitions) these are consequential updates because of the rationalisation of OC2 and do not attempt to rationalise or simplify the Planning Code or Glossary and Definitions. These changes are summarised in more detail below and the full legal text is available in Annex 04. Collaboration with electricity industry stakeholders is essential in gaining a better insight as to what adds most value in attempting to simplify the Grid Code, and the formal modification of OC2 will be a key building block in the process. While every effort was made by the Proposer to engage industry stakeholders during this work, this was a challenge at times due to limited engagement, which may have been due to resource constraints and prioritisation of other work. The ASRW provided industry parties with the opportunity to provide early and detailed input towards the structure, content, breadth, and depth of redrafting OC2, and had developed some proposed legal text before the proposal entered this formal code modification process. The GC0164 Workgroup agreed to retain one set of definitions instead of creating a separate set for each simplified section of the Grid Code. The Proposer recommended that, in addition to the specific code modification, the Workgroup could consider how effective the process of proposal development has been, and whether it is suitable for wider adoption in relation to Grid Code alignment, simplification and rationalisation modifications. Due to the nature of this modification, i.e. seeking to make OC2 clearer by reviewing and re-writing sections of the Code without altering the requirements, it has been challenging to clearly present the changes made. The tables below contain a summary, but a more detailed comparison of the current version of OC2 with that proposed is available in Annex 05. 7 Public Summary of the changes to OC2 Section of OC2 What has changed 1. The Introduction, Objective, and Scope Have been rewritten in plain English and the text has been rationalised. 2. Descriptions of procedures Have been simplified and rationalised. Sections describing timelines have been amended to include diagrams to make them more comprehensible. 3. Text Flowcharts have been used to remove repetitive text. Overall text length (number of words) has been reduced 4. Generator performance charts Are proposed to be relocated in the Planning Conditions 5. All sections Changes have been made to improve readability and make text more concise Summary of changes to the Data Registration Code Section of the Data Registration Code What has changed OC2 references Have been updated Schedule 1 Power Generating Module Performance Chart has been introduced. 8 Public Summary of the Changes to the Planning Code Section of the PC What has changed 1. PC.A.3.2.2(f) Sub item (vi) ‘Generator Performance Chart(s) shall be in the format indicated in the Planning Code Appendix G’ was added to introduce location of the charts in the Appendix G. 2. APPENDIX G Introduced as new location of Performance Chart Examples Summary of the changes to the Glossary and Definitions Section of the Glossary and Definitions What has changed National Electricity Transmission System ‘NETS’ has been added as an abbreviated form of the ‘National Electricity Transmission System’. What is the impact of this change? Proposer’s assessment against Grid Code Objectives Relevant Objective Identified impact (i) To permit the development, maintenance and operation of an efficient, coordinated and economical system for the transmission of electricity; Neutral (ii) Facilitating effective competition in the generation and supply of electricity (and without limiting the Positive 9 Public foregoing, to facilitate the national electricity transmission system being made available to persons authorised to supply or generate electricity on terms which neither prevent nor restrict competition in the supply or generation of electricity); Users will find it easier to find information, saving time in determining compliance requirements. (iii) Subject to sub-paragraphs (i) and (ii), to promote the security and efficiency of the electricity generation, transmission and distribution systems in the national electricity transmission system operator area taken as a whole; Neutral (iv) To efficiently discharge the obligations imposed upon the licensee by this license* and to comply with the Electricity Regulation and any relevant legally binding decisions of the European Commission and/or the Agency; and Neutral (v) To promote efficiency in the implementation and administration of the Grid Code arrangements Positive A more usable version of OC2 will make it easier for Users to implement their obligations correctly and for the NESO to administer the Grid Code. Establishing a streamlined modification process for code alignment, simplification and rationalisation will help deliver more wide-ranging efficiency improvements to 10 Public the codes, including Energy Code Reform. 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 Positive Clearer obligations and easier implementation of them will help improve system reliability. Lower bills than would otherwise be the case Positive Lower Grid Code administration overheads across the industry will help to reduce bills. Benefits for society as a whole Neutral Reduced environmental damage Neutral Improved quality of service Positive Simplification of OC2 will result in more efficient use in complying with and understanding OC2. 11 Public Legal text The legal text for this change can be found in Annex 04. Please see the below table which indicates a summary of legal text changes with the interactions and additional changes required for if GC0183 is approved prior to a GC0164 decision. Legal text document Summary of changes under GC0164 Additional changes if GC0183 is approved prior to GC0164 decision Glossary and Definitions Simplification of NETS definitions and change to references Addition of definitions introduced under GC0183 (provided for context as these are referred to in OC2) Operating Code 2 Complete change to document for simplification Addition of text written in GC0183 Operating Code 5 Change to references N/A Operating Code 7 N/A Addition of text written in GC0183 including a change to a reference in this clause Balancing Code 1 Change to references Addition of text written in GC0183 including a change to a reference in this clause Balancing Code 2 Change to references N/A European Compliance Processes Change to references N/A General Conditions Change to references N/A 12 Public Data Registration Code Addition of Power Generating Module Performance Chart and checkbox Change to references N/A Planning Code Addition of Generator Performance Chart examples in Appendix G N/A Workgroup considerations Workgroup Discussion ahead of the Workgroup Consultation The Workgroup convened 12 times to discuss the perceived issue, detail the scope of the proposed defect, discuss the proposed solution, and assess the proposal in terms of the Applicable Code Objectives. The modification initially followed the Standard Governance route, but it was agreed by the Authority after Workgroup 1 that GC0164 should proceed to a Self- Governance route. The Authority assessed the modification proposal and decided that the intended changes to OC2 bore no material impact to Grid Code Users. Grid Code Panel members met on 25 January 2024 and agreed that GC0164 would follow the Self-Governance route and that the Terms of Reference should be updated accordingly. The Terms of Reference can be found in Annex 02. Due to a proposed change to the Data Registration Code (DRC) highlighted during the first Code Administrator Consultation, the Grid Code Panel, directed the Code Administrator to retract the Self-Governance statement under GC.2.4.11 and advised that the modification would follow the Standard Governance route. Further details can be found in the Workgroup discussions following Panel send back section on page 18. The Proposer delivered a presentation comparing the existing legal text with the revisions proposed by the Alignment, Simplification and Rationalisation Workstream (ASRW). Workgroup members undertook a detailed, page-by-page review of these suggested amendments, carefully evaluating each change to 13 Public ensure it met the intended objectives. In cases where modifications were deemed to have potentially significant impacts, or where the original language was already sufficiently clear, the group elected to retain the existing text. A member of the Workgroup raised concerns regarding the potential risks associated with altering or removing content from the existing OC2, cautioning that reducing detail might increase the risk of ambiguous interpretation. In response, the Proposer clarified that the primary objective was to streamline and clarify OC2’s language, ensuring the text remains both concise and unambiguous. A Workgroup member further emphasised the importance of considering the broader implications of any changes to definitions, particularly their potential impact on other sections of the Grid Code and related industry codes. The Proposer acknowledged this point, clarifying that there is no intention for the amendments to have a material effect elsewhere. Should the process of revising definitions prove too complex, the Proposer suggested that this task could be addressed separately at a later stage. Term of Reference (f) discussion Workgroup members also discussed item (f) in the Terms of Reference “Consider whether it is appropriate to have two sets of Grid Code definitions, one set to use with OC2 and a second (existing) set to be used for all other parts of the Grid Code’’. Workgroup members agreed that having two sets of Glossary and Definitions would cause confusion and therefore it was sensible to have one single set that covers the entire Grid Code. Legal Text Discussions During legal text discussions in Workgroup meeting 4, a Workgroup member sought clarification regarding references to Generator Performance Charts in the newly created Appendix G section of the Planning Code. The Proposer confirmed there was reference in OC2 regarding Generator Performance Charts, and that the key question was where in the Planning Code the reference should be introduced. 14 Public This was discussed and Workgroup members agreed that the Generator Performance Charts should be moved to a new Appendix G within the Planning Code. A new reference text was proposed and drafted in PC.A.3.2.2(f) as a result of the discussion. A recommendation was put forward to include a legal text reference table previously distributed by the Proposer to the Workgroup, highlighting the changes made to OC2 in the Annexes. This addition was intended to enhance industry stakeholders’ understanding of the proposed modification. The Proposer agreed and subsequently prepared a comparative document outlining the differences between the current and revised versions of OC2. This resource aims to assist readers who were not directly involved in the GC0164 process in evaluating the changes in relation to the stated objectives. The reference table is available in Annex 05. Workgroup Consultation Summary The Workgroup Consultation was held between 07 June – 08 July 2024 and received 3 responses. The full responses and a summary of the responses can be found in Annex 06. Applicable Objectives4 Met: Respondent one believed the original proposal better facilitated Grid Code objectives (a), (b), (c) and (d). Respondent two believed the original proposal better facilitated Grid Code objective (e). Respondent three believed the original proposal better facilitated Grid Code objectives (a), (c) and (e). Implementation approach: All three respondents supported the implementation approach. 4 On 01 October 2024, the Electricity System Operator (ESO) was formally rebranded as the National Energy System Operator (NESO). Concurrently, the ESO Licence was updated, transitioning the objectives from alphabetical to Roman numeral enumeration. 15 Public Alternatives: None of the respondents wished to raise an alternative. Have the changes to OC2 made it easier to understand than the existing version?: Respondents one and three agreed that the changes proposed had made it easier to understand than the existing version. Respondent two however advised that it was difficult to form a view. Would the Grid Code obligation remain the same if this version was implemented?: Respondents one and three confirmed that the Grid Code obligation would remain unchanged. Respondent two noted that some requirements have been changed/removed, adding changes may not have been intentional and were due to editorial changes. The Workgroup view is there should only be one set of Glossary and Definitions applicable to the entire Grid Code, do you agree?: Respondents two and three supported the view that a single, consolidated set of Glossary and Definitions should apply across the entire Grid Code, noting that the existence of multiple definitions for the same term would introduce unnecessary confusion. Conversely, respondent one disagreed, considering this approach a significant error that could impede the progress of the dWSTC project. The Generators Performance Charts will move from the Operating Code to the Planning Code under this Proposal, do you agree with this change?: All respondents agreed with this change, one respondent added that there are some further areas of OC2 which relate to the Generator Performance Chart which could be moved into the Planning Code. To help quantify the industry resources required to implement this type of change, the consultation asked respondents to indicate the number of hours spent reading and responding to the consultation: Respondent one advised it was difficult to quantify a number as they had spent more than one hundred hours overall working on the dWSTC project and GC0164 modification. Respondents two and three advised they had spent 16 Public approximately 5 and 10 hours reading and responding to the consultation. Details of the responses and summary can be found in Annex 06. Post Workgroup Consultation Discussion During the review of the legal text, several amendments were highlighted by a Workgroup member; the Proposer agreed to make the necessary changes and shared the updates with Workgroup members for their review. Terms of Reference Overview a) Implementation and costs It was suggested that Workgroup members share details of the time and effort invested during the modification process, this information could then be taken into consideration when deciding on similar projects in the future. The Workgroup Consultation received three responses regarding time and effort invested, with reported hours ranging from one to approximately one hundred, reflecting varying levels of involvement among respondents. b) Review draft legal text should it have been provided. If legal text is not submitted within the Grid Code Modification Proposal the Workgroup should be instructed to assist in the developing of the legal text A Workgroup member highlighted to the group that other areas within the Grid Code should be reviewed to ensure nothing has been missed, and updates were reflected correctly in OC2. The Proposer agreed to do a full review of the Grid Code and share their findings with members. The Proposer had previously reviewed the Grid Code to ensure the suggested changes within the legal text would not have any adverse effect but agreed to do a further assessment. At a later meeting the Proposer advised Workgroup members that no issues were found after a second review. c) Consider whether any further Industry experts or stakeholders should be invited to participate within the Workgroup to ensure that all potentially affected stakeholders have the opportunity to be represented in the 17 Public Workgroup. Demonstrate what has been done to cover this clearly in the report The Proposer engaged with industry through various forums to obtain feedback in relation to the OC2 changes. A Workgroup member highlighted that it was important that feedback be received by industry parties affected by the OC2 changes. It was agreed that the Proposer would attend the OC2 Forum and share the changes made to OC2 and request feedback. Workgroup members also agreed to assist by reaching out to relevant parties to request their input. During the OC2 Forum on 24 September 2024, the Proposer shared the GC0164 documentation with the forum members. The request was for members to feedback via a questionnaire whether the suggested changes made the document easier to use for industry, those members who responded felt the revised OC2 changes were easier to follow. The Chair explained that after reaching out to Industry, receiving feedback from Stakeholders at the OC2 forum and welcoming a new Workgroup member, Terms of Reference (c) had been fulfilled. The Workgroup members agreed and noted that the Proposer could not have done more to engage with industry to gain their feedback. d) Consider implications to sections linked to the Regulated Sections of the Grid Code During discussions, a question was raised regarding Term (d), a member asked whether the implications on the Electricity Balancing Regulation (EBR) Terms and Conditions had been considered. The Proposer explained that this was addressed in earlier Workgroup discussions and confirmed that GC0164 does not have any EBR implications. Another Workgroup member supported this view and added that the modification does not change the obligations within OC2 and should not have any implications.5 5 During the Workgroup period, no issues were identified concerning the Electricity Balancing Regulations (EBR). However, during the First Code Administrator Consultation, it became apparent that an amendment to the Data Registration Code was necessary. 18 Public e) Consider whether the proposed redrafted OC2 is easier for stakeholders to read and understand and that the existing obligations on all parties set out in the current OC2 version have been retained. During Workgroup discussions, it was agreed that although the Proposer had tried numerous times to engage with Stakeholders, further engagement was needed to ensure the redraft adequately addresses their concerns. As set out in the Terms of Reference (e) the Proposer attended the OC2 Forum, sharing the suggested changes and requested feedback from members. Those members who responded agreed the redraft was easier to read and the obligations on all parties set out in the current OC2 had been retained. This was reiterated by Workgroup members during discussion through the modification process. f) Consider whether it is appropriate to have two sets of Grid Code definitions, one set to use with OC2 and a second (existing) set to be used for all other parts of the Grid Code. The Proposer during Workgroup discussion advised that two sets of Grid Code definitions had been considered but was deemed impractical due to the potential confusion it would cause for readers. Workgroup members agreed noting that having two sets of definitions would contradict the overall objective of simplifying the code. g) Workgroup to assess and form a view whether there are material changes or not to the modification. Workgroup members have reviewed the legal text changes and confirmed they agree there have been no material changes. First Workgroup Vote The Workgroup met on 18 October 2024 to carry out their Workgroup Vote. The full Workgroup vote can be found in Annex 07. The table below provides a summary of the Workgroup Members view on the best option to implement this change. 19 Public For reference the Applicable Grid Code Objectives are: i. To permit the development, maintenance and operation of an efficient, coordinated and economical system for the transmission of electricity ii. Facilitating effective competition in the generation and supply of electricity (and without limiting the foregoing, to facilitate the national electricity transmission system being made available to persons authorised to supply or generate electricity on terms which neither prevent nor restrict competition in the supply or generation of electricity); iii. Subject to sub-paragraphs (i) and (ii), to promote the security and efficiency of the electricity generation, transmission and distribution systems in the national electricity transmission system operator area taken as a whole; iv. To efficiently discharge the obligations imposed upon the licensee by this license* and to comply with the Electricity Regulation and any relevant legally binding decisions of the European Commission and/or the Agency; and v. To promote efficiency in the implementation and administration of the Grid Code arrangements * See Electricity System Operator Licence The Workgroup concluded unanimously that the Original better facilitated the Applicable Objectives than the Baseline. Option Number of voters that voted this option as better than the Baseline Original 5 Following the changes to the legal text made after the Panel send-back, the Workgroup confirmed their Workgroup Vote at the meeting on 16 September 2025. First Code Administrator Consultation Summary The first Code Administrator Consultation was issued on 02 December 2024, closed on 16 January 2025 and received 4 responses. The full responses can be found in Annex 10 and a summary of the legal text queries raised can be found in Annex 11. 20 Public First Panel recommendation vote The first Draft Final Modification Report was submitted to the February 2025 Grid Code Review Panel for recommendation. The Panel considered the substantive changes in the legal text and agreed these should be reconsidered by the Workgroup, followed by a second Code Administrator Consultation. Workgroup Discussions following Panel Send Back The Workgroup reconvened 3 times following the Grid Code Review’s Panel for them to reconsider the legal text changes raised in the Code Administrator Consultation. At the Workgroup meeting held on 29 April 2025, Workgroup members considered the feedback received from the Grid Code Review Panel and confirmed that, due to a change now being required to the Data Registration Code (which is referenced in Annex GR.B Table 1), the modification has an interaction with the Electricity Balancing Regulation (EBR). The Workgroup provided this information to the Grid Code Review Panel in June 2025, and the Panel instructed the Code Administrator to retract the Self-Governance Statement under GR.24.11, meaning that the modification should proceed via the Standard Governance process. All identified typographical and substantive issues were compiled and circulated to Workgroup members in a detailed spreadsheet for their review and input Annex 11. The Proposer explained that the review process involved going through the legal text and identifying typographical and substantive issues, emphasising the importance of having an independent Workgroup member review their assessment to ensure accuracy and objectivity. The Workgroup agreed to go through the spreadsheet the Proposer had prepared, which listed the identified issues and their proposed resolutions. This 21 Public collaborative review aimed to ensure that all necessary changes were accurately captured and addressed. The following changes were made to the legal text following discussion by the Workgroup: • Restoration Contractors: The Workgroup discussed the references to restoration contractors in the legal text. A Workgroup member clarified that restoration contractors could include Generators or Interconnector owners and agreed to ensure that the text accurately reflected this. • Generating Plant: The Workgroup addressed the references to generating plant in the legal text and discussed the importance of using consistent terminology and agreed to use "Plant and/or Apparatus" to cover all relevant equipment. • Typographical Corrections: The Workgroup identified and corrected various typographical errors in the legal text. This included ensuring proper punctuation, correcting references, and making sure that all text was clear and consistent. • Consistency and Clarity: The Workgroup emphasised the need for consistency and clarity in the legal text. They discussed the importance of using precise language and ensuring that all references and terminology were used consistently throughout the document. • Diagram and chart issues: The Workgroup identified issues with diagrams and charts in the Planning Code, including missing lines and incorrect titles. The Proposer addressed these issues and also provided legal text within the Data Registration Code to ensure Users have a way of submitting information to NESO. On 16 September 2025, the Workgroup met to finalise the legal text including the interaction with GC0183 and confirm their Workgroup Vote. 22 Public Interaction with GC0183 On 09 July 2025, NESO raised GC0183: Generator and Interconnector Availability During a Severe Space Weather Event. This modification was identified to have an interaction with GC0164, due to proposed changes to OC2 (addition of clauses OC2.4.1.2.4 and OC2.5). Following agreement of the GC0183 legal text on 10 September 2025, the GC0164 Workgroup met on 16 September 2025 to agree changes to the legal text which would be required if GC0183 was approved prior to GC0164. Please see the full legal text in Annex 04 which provides versions of legal text which both include and exclude the additional GC0183 text. Panel Send Back of the Second Code Administration Consultation The Second Code Administrator Consultation was submitted to the Grid Code Panel on 25 September 2025 for their review. During this session, Panel members raised several questions and concerns regarding the consultation. A Panel member highlighted issues relating to terminology, definitions, graphical presentations, and noted a lack of consistency, which impacted the clarity and overall comprehension of the documentation. Another Panel member expressed that the legal text could be confusing for stakeholders, particularly due to the existence of multiple versions considering the interaction with GC0183 and GC0174. It was recommended that the Panel defer progression of the Second Code Administrator Consultation until formal decisions had been reached on GC0183 and GC0174, given that both modifications have implications for GC0164. In response, the Panel Secretary recommended that members with concerns join the Workgroup to collaboratively address and resolve any outstanding matters, thereby ensuring all issues are fully understood. Consequently, the Grid Code Panel did not approve the progression of the modification until all points raised had been satisfactorily addressed. 23 Public The Proposer organised meetings with the concerned Panel members to discuss and resolve all issues raised. It was agreed that the subsequent Workgroup meeting would be scheduled following receipt of the Authority's decisions on GC0183 and GC0174, both of which have implications for GC0164. Panel members confirmed their intention to attend the next Workgroup on 22 January 2026, where they would present their previous concerns and review the amendments made by the Proposer. Workgroup Discussions following Panel Send Back The Workgroup discussed concerns raised by the Grid Code Panel members regarding the GC0164 modification, particularly the need to address additional feedback on the legal text and its interactions with GC0183 and GC0174. The legal text was updated to reflect Ofgem’s recent decisions, and a revised timeline will be presented to the Grid Code Panel in January 2026. The Workgroup addressed the concerns raised by the Grid Code Panel regarding the GC0164 modification, with particular focus on the need to incorporate additional feedback on the legal text and its interactions with GC0183 and GC0174. The legal text was duly updated to reflect the most recent decisions by Ofgem, and it was agreed that a revised timeline would be presented to Grid Code Panel in January 2026. Key areas of discussion included ensuring that code simplification does not result in changes to obligations, enhancing the clarity and consistency of diagrams, eliminating duplication, and aligning terminology with the current Grid Code. The Workgroup reached consensus on specific revisions to formatting, diagrammatic structure, references to performance charts, and the correct integration of related modifications, while prioritising the preservation of the integrity of existing requirements. It was agreed that a further Workgroup would be needed to review these changes. 24 Public On February 11, the Workgroup evaluated the inclusion of a space weather diagram in OC2, emphasising the importance of clarity and consistency. Diagram formatting was standardised and it was agreed that diagrams will be incorporated only where they enhance understanding. In the Planning Code chart titles were revised to align with defined terms, and references were amended to specify all three chart types individually. The Workgroup decided to retain only two versions of diagrams tailored for different user groups and removed example charts from the DRC, preserving them exclusively in Appendix G. After these revisions, the Workgroup reaffirmed that their previously recorded vote remained the same after the updates to the legal text. The Workgroup agreed that all concerns raised had been resolved and the Second Code Administrator Consultation should be submitted to Grid Code Panel for review. On 26 February the Grid Code Panel agreed that GC0164 should proceed to a Second Code Administrator Consultation. Second Code Administrator Consultation Summary The Second Code Administrator Consultation was issued on the 27 February 2026, closed on 27 March 2026 and received 1 non-confidential response and no confidential responses. A summary of the response can be found in the table below, and the full responses can be found in Annex 12. Code Administrator Consultation summary Question Do you believe that the GC0164 Original Proposal better facilitates the Grid Code Applicable Objectives? The proposal is viewed positively, as it aligns with Grid Code Objectives i, iii, and v by simplifying and clarifying the drafting for OC2. The modification aims to use plain English, eliminate duplication, and improve 25 Public navigation, making the Grid Code more efficient and user-friendly. This approach is expected to be extended to other sections, further enhancing the overall effectiveness of the Grid Code. Do you support the proposed implementation approach? Yes - We endorse the revised text, particularly the inclusion of flow diagrams, as these will make navigation quicker and more straightforward. Simplifying and reorganising OC2 of the Grid Code demonstrates that codes written with users in mind—using clear language, flow diagrams and principle-based approaches—significantly improve accessibility. The proposed changes retain existing obligations but also reveal a challenge: some stakeholders favour absolute legal certainty, while others prefer greater clarity and ease of understanding. To further support code simplification, a thorough review of definitions may be required. Do you have any other comments? No other comments were received. Legal text issues raised in the consultation No legal text issues were raised. EBR issues raised in the consultation No EBR issues were raised. 26 Public Panel Recommendation vote The Panel met on the 23 April 2026 to carry on their recommendation vote. They assessed whether a change should be made to the Grid Code by assessing the proposed change against the Applicable Objectives. Vote 1: Does the original facilitate the Applicable Objectives better than the Baseline? Panel Member: Alan Creighton, Network Operator Representative Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - - - - Y Y Voting Statement The proposed text should make this part of the Grid Code easier for Users to understand and it should be implemented. However, I am not convinced that benefits outweigh the significant industry resources consumed to develop the proposal and suggest that resourcing be considered in advance of any similar modifications being proposed which seeks to simplify the way that Grid Code obligations are drafted. Panel Member: Andrew Allan, Generator Representative Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - - - - Y Y Voting Statement The proposal improves ease of interpretation and understanding of OC2. 27 Public Panel Member: Claire Newton, NESO Representative Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - Y - - Y Y Voting Statement A significant amount of NESO and industry effort has gone into this modification, which aims to simplify the text in OC2, without changing the requirements. As a result of this modification, users should find it easier to find information, and requirements should be clearer, saving user time in determining compliance requirements. Panel Member: Darshak Shah, Generator Alternate Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original y - - - y y Voting Statement The proposed modification simplifies the obligation and provides a clearer, easier-to- understand version of the text for users. Panel Member: David Michie, Onshore Transmission Owner Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - - - - Y Y Voting Statement 28 Public Simplification of legal text and the introduction of visual aids will enforce greater clarity and remove complexity from GC02. I support the reduction of overly complex and descriptive detail which makes decision making difficult for users. Panel Member: David Monkhouse, Offshore Transmission Licensee Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - - - - Y Y Voting Statement The proposed modification simplifies and rationalises the text within OC2 which is a benefit to users of the Grid Code. Panel Member: Graeme Vincent, Network Operator Representative Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - - - - Y Y Voting Statement The proposed simplification and rationalisation of OC2 should aid easier understanding and navigation by Grid Code Users. Panel Member: John Harrower, Generator Representative Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - - - - Y Y Voting Statement 29 Public This modification aims to simplify and streamline a section of the Grid Code which should improve readability. Any future repetition should weigh up the perceived benefits against the time and resource expended on the simplification of OC2. Panel Member: Sigrid Bolik, Generator Representative Better facilitates AO (i)? Better facilitates AO (ii)? Better facilitates AO (iii)? Better facilitates AO (iv)? Better facilitates AO (v)? Overall (Y/N) Original - Y Y - Y Y Voting Statement Alignment and simplification of paragraphs and inclusion of visual description allow for easier understanding of the obligation. Vote 2 – Which option best meets the Applicable Objectives? Panel Member Best Option Which objectives does this option better facilitate? (If baseline not applicable). Alan Creighton Original v Andrew Allan Original v Claire Newton Original ii, v Darshak Shah Original i, v David Michie Original v David Monkhouse Original v Graeme Vincent Original v John Harrower Original v Sigrid Bolik Original ii, iii, v 30 Public Panel Conclusion The Panel recommended unanimously that the original better facilitated the Applicable Grid Code Objectives. When will this change take place? Implementation date: 10 Business Days after Authority Decision Date decision required by: As soon as possible. Implementation approach: There are no system changes required as a result of this modification. ☐CUSC ☐BSC ☐STC ☐SQSS ☐European Network Codes ☒EBR Article 18 T&Cs6 ☒Other modifications ☐Other This modification has an interaction with the Electricity Balancing Regulation Article 18 Terms and Conditions due to changes to the Data Registration Code. There is also an interaction with GC0183 and GC0174, which makes changes to Operating Code 2. 6 If the modification has an impact on Article 18 T&Cs, it will need to follow the process set out in Article 18 of the Electricity Balancing Regulation (EBR – EU Regulation 2017/2195) – the main aspect of this is that the modification will need to be consulted on for 1 month in the Code Administrator Consultation phase. N.B. This will also satisfy the requirements of the NCER process. 31 Public Acronyms, key terms and reference material Acronym / key term Meaning ASRW Alignment, Simplification and Rationalisation Workstream BSC Balancing and Settlement Code CMP CUSC Modification Proposal CUSC Connection and Use of System Code DRC Data Registration Code dWSTC Digitalised Whole System Technical Code EBR Electricity Balancing Regulation ECR Energy Codes Reform NESO National Energy System Operator OC2 Operating Code No.2 PC Planning Code SQSS Security and Quality of Supply Standards STC System Operator Transmission Owner Code T&Cs Terms and Conditions Annexes Annex Information Annex 01 GC0164 Proposal Form Annex 02 GC0164 Terms of Reference Annex 03 GC0164 ASRW Considerations Annex 04 GC0164 Legal Text Annex 05 GC0164 Legal Text Comparison Documents Annex 06 GC0164 Workgroup Consultation and responses Annex 07 GC0164 Workgroup Vote Annex 08 GC0164 Action Log 32 Public Annex 09 GC0164 Attendance Record Annex 10 GC0164 First Code Administrator Consultation Responses Annex 11 GC0164 Summary of Legal Text queries from First Code Administrator Consultation Annex 12 GC0164 Second Code Administrator Consultation Responses