Capacity Market Modifications
Capacity Modifications Workshops consider any change to the Capacity Market Code. A Workshop is held every 2 months. Details of scheduled meetings can be found in the meetings calendar below.
Capacity Market Modifications Workshops
The Capacity Market Workshop forms part of the Capacity Market Modification process. The objective of this process is to progress Capacity Market Modification Proposals with a view to better facilitating the achievement by the Capacity Market Code of the Capacity Market Code Objectives.
Use the link below to see the full calendar of scheduled meetings. Each meeting event containts the relevant agenda and minutes.
See the meetings calendar| Mod ID | Title | Mod Status | Stage | Section Affected | Effective Date | Publication Date |
|---|---|---|---|---|---|---|
| CMC_18_25 | Introduction of Modular Generator Unit Types and De-rating Methodology | New | Active | Appendix D, Glossary, Section E | ||
| CMC_17_25 | Drawdown of Performance Security | New | Active | Section J | ||
| CMC_16_25 | CRM De-rating factors for DSU | New | Active | Section C, Section D | ||
| CMC_15_25 | Performance Securities for Extended Projects in T-4 2026/2027 | RA Decision: Recommended for Rejection | Closed | Section J | ||
| CMC_14_25 | New Dates in Capacity Auction Timetable | In Consultation | Active | Appendix C, Section C, Section F | ||
| CMC_13_25 | Amendments to Capacity Auction Timetable | RA Decision: Approved (Revised Legal Drafting) | Active | Section D | 29/08/2025 | |
| CMC_12_25 | RAs role in relation to FQDs | RA Decision: Approved (Revised Legal Drafting) | Active | Section B, Section E | 29/08/2025 | |
| CMC_11_25 | Clarification on provisions relating to 'final and binding' and dispute resolution under the CMC | In Consultation | Active | Section B, Section E, Section F | ||
| CMC_10_25 | Amendments to E.7 | RA Decision: Approved (Not Vetoed) | Active | Section E | 29/08/2025 | |
| CMC_09_25 | Registration and Qualification Auction Timetable Milestones | In Consultation | Active | Appendix C, Appendix E, Glossary, Agreed Procedure 3 | ||
| CMC_08_25 | Ensuring robust transparent and objective qualification criteria in the Capacity Market | In Consultation | Active | Appendix D, Section E | ||
| CMC_07_25 | Maintaining Net Present Value in new capacity market contracts for no fault delays | RA Decision: Recommended for Rejection | Closed | Glossary, Section J | ||
| CMC_06_25 | Amendment of ARHL De-rating Factor Definition to Exclude Intermediate Length Contracts | RA Decision: Recommended for Rejection | Closed | Glossary | ||
| CMC_05_25 | Early Termination of Intermediate Length Contract Capacity | RA Decision: Recommended for Rejection | Closed | Section J | ||
| CMC_04_25 | Adjustment of CMC auction qualification criteria to facilitate complex projects within State Aid Approval | RA Decision: Recommended for Rejection | Closed | Glossary, Section E | ||
| CMC_03_25 | Clarification of Proportion of Delivered Capacity for multiple tranches | RA Decision: Approved (Not Vetoed) | Active | Section G | 16/07/2025 | |
| CMC_02_25 | Separate De-rating Factor for New Vs Existing Capacity | RA Decision: Recommended for Rejection | Closed | Appendix D, Section C, Section D, Section E, Section G, Section I | ||
| CMC_01_25 | Provision of Information Related to Application Rejection under E.7 | RA Decision: Approved (Revised Legal Drafting) | Active | Section E | 29/08/2025 | |
| CMC_12_24 | Proportion of Delivered Capacity in respect of incremental New Capacity | Withdrawn | Closed | Section G | ||
| CMC_11_24 | Implementation of Early Delivery Incentives according to SEMC Decision Paper SEM-24-037 | RA Decision: Approved (Not Vetoed) | Closed | Appendix F, Glossary, Section D, Section F | 17/09/2024 | |
| CMC_10_24 | Introduction of Intermediate Length Contracts | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section D, Section E, Section F, Section G, Section J, Section M | 17/09/2024 | |
| CMC_09_24 | Amendments to J.5.7 and J.5.8 | RA Decision: Approved (Not Vetoed) | Closed | Section J | 27/09/2024 | |
| CMC_08_24 | Widening of Longstop Extension Process to Awarded Capacity for 2023-24 Auction | RA Decision: Approved (Not Vetoed) | Closed | Section J | 27/09/2024 | |
| CMC_07_24 | Treatment of Capacity Contracts of Varying Duration in Constrained Auction Solution | RA Decision: Further review required | Active | Section F | ||
| CMC_06_24 | Performance Securities for Extended Projects | RA Decision: Recommended for Rejection | Closed | Section J | ||
| CMC_05_24 | Amendment to J.6.1.6 to recognise extensions granted under SEM-23-101 and SEM-23-108 | RA Decision: Approved (Not Vetoed) | Closed | Section J | 01/10/2024 | |
| CMC_04_24 | Recovery of Net Present Value Lost as a Result of No-Fault Delays to New Capacity | RA Decision: Recommended for Rejection | Closed | Glossary, Section J | ||
| CMC_03_24 | Enduring Mechanism for Indexation based on GB Model | RA Decision: Recommended for Rejection | Closed | Section F | 03/10/2024 | |
| CMC_02_24 | Modification to the Performance Security Requirement | RA Decision: Recommended for Rejection | Closed | Section J | ||
| CMC_01_24 | Amendment to criteria to achieving Substantial Financial Milestone | Withdrawn | Closed | Section J | ||
| CMC_25_23 | Market Readiness Certification | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section C, Section G, Section J | 12/01/2024 | |
| CMC_24_23 | Revision of the Exception Application Timelines | RA Decision: Recommended for Rejection | Closed | Agreed Procedure 3, Glossary, Section J | ||
| CMC_23_23 | Mitigation of Impact on Participants relating to System Operator Grid Connection delays | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section J | 01/01/2024 | |
| CMC_22_23 | Indexation of Capacity Payment Price for inflation | Recommended For Rejection | Closed | Appendix F, Glossary, Section F | 01/10/2024 | |
| CMC_21_23 | Minimum Completion on Receipt of Interim Operational Notification | RA Decision: Recommended for Rejection | Closed | Section C, Section G, Section J | ||
| CMC_20_23 | Amendment to Timing of Opt Out Notifications | RA Decision: Recommended for Rejection | Closed | Section E | ||
| CMC_19_23 | Modification to implement the SEMC Decision set out in SEM-23-038 and SEM-23-045 | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section E, Section F | 12/12/2023 | |
| CMC_18_23 | Amendment to Definition of Third Party Extension Period | RA Decision: Approved (Not Vetoed) | Closed | Glossary | 16/02/2024 | |
| CMC_17_23 | Updates to LCC Areas | RA Decision: Approved (Not Vetoed) | Closed | Section C, Section D | 03/10/2023 | |
| CMC_16_23 | Extension to New Capacity Impacted by Indexation | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section J | 01/01/2024 | |
| CMC_15_23 |
Amendment to Performance Securities for Extended Projects
|
RA Decision: Approved (Not Vetoed) | Closed | Section J | 08/09/2023 | |
| CMC_14_23 | LCC Violation Criteria | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section F | 03/10/2023 | |
| CMC_13_23 | Min Completion Prior to Long Stop Date | RA Decision: Approved (Not Vetoed) | Closed | Section G, Section J | 20/12/2023 | |
| CMC_12_23 | Facilitation of Unit Specific Price Caps for Existing Capacity in Excess of the Auction Price Cap | RA Decision: Recommended for Rejection | Closed | Glossary, Section J | ||
| CMC_11_23 | Amendment to Drafting Introduced Under Modification CMC_15_22 | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section J | 22/11/2023 | |
| CMC_10_23 | Mitigation of Impact on Participants relating to 3rd Party Gas Connection delays | RA Decision: Approved (Not Vetoed) | Closed | Glossary, Section J | 01/01/2024 | |
| CMC_09_23 | Removal of Section J.6.1.6 (1) | RA Decision: Approved (Not Vetoed) | Closed | Section J | 01/01/2024 | |
| CMC_08_23 | Typographical Correction Capacity Aggregation Threshold | RA Decision: Approved (Not Vetoed) | Closed | 11/12/2023 | ||
| CMC_07_23 | Special Application of ISTA | RA Decision: Approved (Not Vetoed) | Closed | Section M | 02/10/2023 | |
| CMC_06_23 | Second ARHL Modification to Complete SEM-22-044 | RA Decision: Approved (Not Vetoed) | Closed | Section E, Section G, Section I | 11/01/2024 | |
| CMC_05_23 | Resolving inconsistency in definition of Existing Capacity Arising from CMC_11_22 | RA Decision: Approved (Not Vetoed) | Closed | 08/02/2024 | ||
| CMC_04_23 | Introduction of Remedial Action for Unforeseeable Delays Due To Extraordinary Supply Chain Impacts | RA Decision: Approved (Not Vetoed) | Closed | Section E, Section J | 01/01/2024 | |
| CMC_03_23 | Amendment of Long Stop Date for T-1 Capacity Auction | RA Decision: Approved (Not Vetoed) | Closed | Section J | 30/06/2023 | |
| CMC_02_23 | Amendment of Milestones Associated with Substantial Financial Completion | Withdrawn | Closed | Section J | ||
| CMC_01_23 | Amendment to Substantial Completion Drafting | RA Decision: Approved (Not Vetoed) | Closed | Section J | 01/01/2024 | |
| CMC_16_22 | Secondary Trading Delays to Awarded New Capacity | Withdrawn | Closed | Section E, Section J, Section M | ||
| CMC_15_22 |
Introduction of New Remedial Action to enable extensions due to planning and Permitting Delays
|
RA Decision: Approved (Not Vetoed) | Closed | Section J | 20/01/2023 | |
| CMC_14_22 |
Modification re-Mitigation of impact of Third-Party delays on Participants and extension of Support term
|
Withdrawn | Closed | |||
| CMC_13_22 | Judicial Review Remedial Action | RA Decision: Approved (Not Vetoed) | Closed | Section J | 20/01/2023 | |
| CMC_12_22 | Remedial Action in the event of planning application to a project that qualifies under a Direction | RA Decision: Approved (Not Vetoed) | Closed | Section J | 20/01/2023 | |
| CMC_11_22 | De-rating for Annual Run Hours Limits | RA Decision: Approved (Not Vetoed) | Closed | Section C, Section D, Section E, Section G, Section I | 05/09/2022 | |
| CMC_10_22 | Introduction of New Remedial Action in the event of Third Party Delays | RA Decision: Recommended for Rejection | Closed | Section J | 14/10/2022 | |
| CMC_09_22 | Secondary Trade Approval Notification | RA Decision: Approved (Not Vetoed) | Active | Section M | ||
| CMC_08_22 | Local Capacity Constraints Maximum Quantities | RA Decision: Approved (Not Vetoed) | Closed | Section C, Section F | 30/09/2022 | |
| CMC_07_22 | Joint Market Registration Variation in Mix | RA Decision: Recommended for Rejection | Closed | Section G, Section I | 30/09/2022 | |
| CMC_06_22 | New Interdependent Combined Units | Withdrawn | Closed | Section E, Section F | ||
| CMC_05_22 | Housekeeping Mod to Update Overlap between CMC_03_21 and CMC_04_21 | RA Decision: Approved (Not Vetoed) | Closed | Section J | 01/07/2022 | |
| CMC_04_22 | New Reference Rates for Default Interest | RA Decision: Approved (Not Vetoed) | Closed | 30/09/2022 | ||
| CMC_03_22 | Transparency on Publication of Qualification Results | RA Decision: Approved (Revised Legal Drafting) | Closed | Section E | 08/07/2022 | |
| CMC_02_22 | Timely Publication of FAIP | RA Decision: Approved (Revised Legal Drafting) | Closed | Section F | 08/07/2022 | |
| CMC_01_22 | New Interdependent Combined Units | RA Decision: Approved (Revised Legal Drafting) | Closed | Section E | 08/07/2022 | |
| CMC_12_21 | Modification to the methodology for calculating the De-Rated Grid Code Commissioned Capacity | RA Decision: Approved (Not Vetoed) | Closed | Section G | 19/11/2021 | |
| CMC_11_21 | Extending Current ASTN Form | RA Decision: Approved (Not Vetoed) | Active | Section M | ||
| CMC_10_21 | Modification to the provisions for Market Registration of Demand Side Units | Withdrawn | Closed | Section E, Section G, Section I | ||
| CMC_09_21 | Timeframe to consider SFC Extensions | RA Decision: Approved (Not Vetoed) | Closed | Section J | 21/09/2021 | |
| CMC_08_21 | Ex-post Verification of Compliance with the CO2 Limits | RA Decision: Approved (Not Vetoed) | Closed | Section I | 02/11/2021 | |
| CMC_07_21 | E.4 Application for Qualification Update | RA Decision: Approved (Not Vetoed) | Closed | Section E | 02/11/2021 | |
| CMC_06_21 | NIRO and DSU | RA Decision: Approved (Not Vetoed) | Closed | Section E, Section I | 21/09/2021 | |
| CMC_05_21 | Substitution of Candidate Units | RA Decision: Recommended for Rejection | Closed | Section J | ||
| CMC_04_21 | Verification Requirements for Implementation Plan Milestones | RA Decision: Approved (Not Vetoed) | Closed | Section J | 14/07/2021 | |
| CMC_03_21 |
Modification to the provisions for Substantial Financial Completion
|
RA Decision: Approved (Not Vetoed) | Closed | Section J | 19/11/2021 | |
| CMC_02_21 | Amendment to Capacity Market Code Modifications Workshop Agenda Timeline | RA Decision: Approved (Not Vetoed) | Closed | Section B | 14/07/2021 | |
| CMC_01_21 | Amendment relating to the provision of the CAM Report following a Capacity Auction | RA Decision: Approved (Not Vetoed) | Closed | Section B | 14/07/2021 | |
| CMC_12_20 | Fix to Seller Limit in CMC_09_19 | Withdrawn | Closed | Section M | ||
| CMC_11_20 |
Providing greater flexibility for the current interim Secondary Trading Notification (ISTN) process
|
RA Decision: Approved (Not Vetoed) | Closed | Section M | 26/10/2020 | |
| CMC_10_20 | Change to determinations made in F.4.1.1 | RA Decision: Approved (Not Vetoed) | Closed | Section F | 26/10/2020 | |
| CMC_09_20 | Modification to the Long Stop Date for the CY2020 / 21 T-1 Capacity Auction | RA Decision: Approved (Not Vetoed) | Closed | Section M | 28/08/2020 | |
| CMC_09_19B | Addendum | RA Decision: Approved (Not Vetoed) | Closed | Section M | 13/11/2020 | |
| CMC_08_20 | Change Awarded Existing Capacity to Awarded New Capacity | RA Decision: Recommended for Rejection | Closed | Section I | ||
| CMC_07_20 | Change in Technology Class | RA Decision: Approved (Not Vetoed) | Closed | Section C, Section G, Section J | 18/01/2021 | |
| CMC_06_20 | Combining Capacity Units into a Capacity Market Unit – Proposed Changes | RA Decision: Recommended for Rejection | Closed | Section E | ||
| CMC_05_20 | Implement amendments as required by the Clean Energy Package Regulation EU 2019 / 943 | RA Decision: Approved (Not Vetoed) | Closed | Section D, Section E, Section J | 27/04/2020 | |
| CMC_04_20 | Providing greater flexibility for New Capacity to combine candidate units into a single Capacity Market Unit | RA Decision: Recommended for Rejection | Closed | Section E | ||
| CMC_03_20 | Modification to the Long Stop Date for the CY2023 / 24 T-4 Capacity Auction | RA Decision: Approved (Not Vetoed) | Closed | Section M | 30/03/2020 | |
| CMC_02_20 | Modification to the required time frame for a T-4 Capacity Auction to take place | RA Decision: Approved (Not Vetoed) | Closed | Section M | 12/02/2020 | |
| CMC_01_20 | Modification to the required time frame for a T-4 Capacity Auction to take place | Withdrawn | Closed | Section D | ||
| CMC_09_19 |
Supplementary Interim Secondary Trading
|
RA Decision: Approved (Not Vetoed) | Closed | Section M | 13/11/2020 | |
| CMC_08_19 | Housekeeping Mod E.8.2.5 & E.8.2.8 | RA Decision: Approved (Not Vetoed) | Closed | Section E | 17/02/2020 | |
| CMC_07_19 | Treatment of Multiyear Contracts in the Event of Simultaneous Capacity Auctions | RA Decision: Recommended for Rejection | Closed | Section E, Section F | ||
| CMC_06_19 |
Modification to the Proportion of Delivered Capacity calculation (G.3.1.4)
|
RA Decision: Approved (Not Vetoed) | Closed | Section G | 12/09/2019 | |
| CMC_05_19 | Housekeeping Changes | RA Decision: Approved (Not Vetoed) | Closed | Section F, Section J | 12/09/2019 | |
| CMC_04_19 | Finalisation of Exchange Rate in Auction Information Pack | RA Decision: Recommended for Rejection | Closed | Section D | ||
| CMC_03_19 | Treatment of Exempt Price-Quantity Pairs | RA Decision: Approved (Not Vetoed) | Closed | Definitions, Section F | 20/03/2019 | |
| CMC_02_19 | Negative Interest | RA Decision: Approved (Not Vetoed) | Closed | Section B, Section J | 20/03/2019 | |
| CMC_01_19 | Interim Solution for Conducting Capacity Auctions | RA Decision: Approved (Not Vetoed) | Closed | Section M | 20/03/2019 | |
| CMC_25_24 | capacity-market-modifications | Closed | Appendix A, Appendix B, Agreed Procedure 5 | 18/11/2024 | ||
| CMC_14_18 | Proposed Modifications in Regards to the Modification of LCC MW Limits by the RAs | RA Decision: Approved (Not Vetoed) | Closed | Section F | 30/11/2018 | |
| CMC_13_18 | Modification to Letter of Credit | RA Decision: Approved (Not Vetoed) | Closed | 30/11/2018 | ||
| CMC_12_18 | Tolerance Class | RA Decision: Approved (Not Vetoed) | Closed | Definitions, Section D, Section E | 30/11/2018 | |
| CMC_11_18 | Long Stop Date | RA Decision: Approved (Not Vetoed) | Closed | Definitions, Section D, Section J | 30/11/2018 | |
| CMC_10_18 | Paragraph B.10.4.1 Report on Capacity Auction | RA Decision: Approved (Not Vetoed) | Closed | Section B | 01/10/2018 | |
| CMC_09_18 | Paragraph E.9.5.1 Publication of Qualification Results | RA Decision: Approved (Not Vetoed) | Closed | 01/10/2018 | ||
| CMC_08_18 | Typographical Correction – E.8.2.4 | RA Decision: Approved (Not Vetoed) | Closed | 01/10/2018 | ||
| CMC_07_18 | Subsection F.9.5 Information Published following a Capacity Auction | RA Decision: Approved (Not Vetoed) | Closed | 01/10/2018 | ||
| CMC_06_18 | Disaggregation of Performance Security Requirements to Capacity Market Auctions | RA Decision: Recommended for Rejection | Closed | Section J | ||
| CMC_05_18 | Combining Candidate Units into a Capacity Market Unit | RA Decision: Recommended for Rejection | Closed | Section F | ||
| CMC_04_18 | F.2.1.1 Capacity Auction Participation | RA Decision: Approved (Not Vetoed) | Closed | Section F | 01/10/2018 | |
| CMC_03_18 | E.5.1.1.A | Withdrawn | Closed | Appendix D, Section E, Section J | ||
| CMC_02_18 | Permitted Disclosures Credit Agencies | RA Decision: Approved (Not Vetoed) | Closed | Section B | 01/10/2018 | |
| CMC_01_18 | NICROS in the CRM | RA Decision: Approved (Not Vetoed) | Closed | Section E | 01/10/2018 |
CMC_18_25 Introduction of Modular Generator Unit Types and De-Rating Methodology.pdf
CMC_07_25 - Submitted Example.xlsx
CMC_07_24TreatmentofCapacityContractsofVaryingDurationinConstrainedAuctionSolutionv2
CMC_09_19-SupplementaryInterimSecondaryTradingSlides