Capacity Market auction: T-4 Auction Monitor Report for 2029 to 2030

The Capacity Market Auction Monitor, Deloitte, has produced a report in relation to the Capacity Market T-4 auction for the 2029 to 2030 delivery year. --- 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Auction Monitor Report 12 March 2026 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Contents 1 Assurance Report 2 Background and Context 3 Report of Observations 4 Confirmation of Bidders to be awarded Capacity Agreements Appendix A – In-scope Capacity Market Rules (Chapter 5) Appendix B – Outline of Work Performed 1 4 6 7 30 31 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 1 Assurance Report ISAE 3000 Independent Reasonable Assurance Report to National Energy System Operator Limited (NESO) (as Electricity Market Reform Delivery Body) on its compliance with selected requirements of the Capacity Market Rules, Regulations and the Auction Guidelines. Scope 1.1 We have performed assurance work over the extent to which the Delivery Body (“DB”) has complied with the selected requirements of Chapter 5 of the Capacity Market Rules (updated 23 June 2025) and the Auction Guidelines (published 10 February 2026) (together the “Rules and Guidelines”). In particular, we have considered the rules included in Chapter 5 of the Capacity Market Rules as listed in Appendix A – In-Scope Capacity Market Rules (Chapter 5) (the “Applicable Rules”). A consolidated version of the detailed Capacity Market Rules is available here: https://assets.publishing.service.gov.uk/media/6911ba14cf24e9250d893e79/i nformal-consolidation-cm-rules-2025.pdf with the subsequent amendments at the time of writing available here: https://www.gov.uk/government/publications/capacity-market-rules. In the context of this Report, the actions of the DB in performing the 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 (“the 2025 T-4 Auction”) is the “Subject Matter” and the Applicable Rules form the “Criteria” against which the Subject Matter has been evaluated. Respective Responsibilities 1.2 The DB as the Responsible Party is responsible for delivering the process and requirements for the 2025 T-4 Auction in accordance with the Capacity Market Rules. Our responsibility, as agreed with the DB, is to assess the actions performed by the DB in performing the 2025 T-4 Auction against the requirements of the Applicable Rules and to independently express an opinion as to whether the process and actions undertaken by the DB comply with the requirements of the Applicable Rules. Other than as defined in our assurance procedures, we did not audit or otherwise test or verify the information given to us in the course of the Services. 1.3 Work Performed We conducted our work in accordance with the International Standard on Assurance Engagements 3000 (Revised) “Assurance Engagements Other Than Audits or Reviews of Historical Financial Information”. That standard requires that we plan and perform our work to obtain appropriate evidence about the 1 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 subject matter of the engagement sufficient to support a reasonable assurance opinion. An outline of the work we performed is included in Appendix B. Except to the extent expressly stated above, we did not subject the information contained in our Report, given to us by the DB (including bids) or included in the input parameters provided by DESNZ (Department for Energy Security and Net Zero), to checking or verification procedures. Inherent limitations 1.4 We obtained reasonable assurance over the actions performed by the DB in operating in performing the 2025 T-4 Auction against the requirements of the Applicable Rules. Inherent limitations exist in all assurance engagements. Any internal control structure, no matter how effective, cannot eliminate the possibility that fraud, errors or irregularities may occur and remain undetected. The procedures we performed were not designed to and are not likely to reveal fraud. Basis of Opinion 1.5 We believe that our work performed and evidence obtained provides a reasonable basis for our opinion. Our assurance report has been produced under our letter of engagement with the Responsible Party effective from 26 June 2025. Assurance Conclusion 1.6 In our opinion the actions performed by NESO, in its role as the Capacity Market Delivery Body for Electricity Market Reform, have in all material respects, complied with the relevant sections of the Rules and Guidelines as detailed in Section 1.1 above in respect of the 2025 T-4 Auction held between 09:00 on 10 March 2026 and 16:45 10 March 2026. A list of the Bidders and corresponding Capacity Market Units (“CMUs”) to be awarded Capacity Agreements following the 2025 T-4 Auction is included in Section 4. Other Matter 1.7 DESNZ made a change to the Capacity Market Rules in June 2025 that specifies that a Bidder may only reduce the Duration Bid in respect of a Bidding CMU that is a Declared Long Stop CMU to certain specified values, as set out in paragraph 5.6.5A. All other Duration Bid Amendments (DBAs) are required to reduce the agreement duration to one year, as set out in paragraph 5.6.5(b). The Auction System was not updated to permit submission of DBAs of a length other than one year for Declared Long Stop CMUs (“impacted CMUs”). The DB developed an alternative process for impacted CMUs to submit a DBA to allow this to be considered within the auction clearing process and correctly 2 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 be reflected in the provisional results. The Delivery Body notified relevant Applicants of the change in process to submit a DBA and communicated this approach to DESNZ, who confirmed in writing that they were content with this approach so long as any DBAs were properly logged for any future auditing purposes. During the T-4 auction the alternative process was not required to operate. Notwithstanding the above we confirmed the determination of the clearing round, clearing quantity and clearing price were performed by the DB in compliance with the Applicable Rules. Our conclusion is not modified in respect of this matter. Independence and Quality 1.8 In conducting our engagement, we have complied with the independence and other ethical requirements of the Code of Ethics for Professional Accountants issued by the International Ethics Standards Board for Accountants and the ICAEW Code of Ethics, which are founded on fundamental principles of integrity, objectivity, professional competence and due care, confidentiality and professional behaviour. Our firm applies International Standard on Quality Management (UK) 1 issued by the Financial Reporting Council and accordingly maintains a comprehensive system of quality control including documented policies and procedures regarding compliance with ethical requirements, professional standards and applicable legal and regulatory requirements. Use of Report 1.9 Our Report has been prepared for the exclusive use of NESO in accordance with the scope agreed within our contract dated 26 June 2025. Our work has been undertaken solely for the purpose of assessing NESO’s compliance with the Rules and Guidelines outlined in Section 1.1 above. Our work was not planned or conducted with any other objective in mind and so cannot be relied upon for any other purposes. Save that a copy of our report may be provided to the Secretary of State for Energy Security and Net Zero and the Gas and Electricity Market Authority and may be published on the www.gov.uk website, our Report is not to be used for any other purpose, recited or referred to in any document, copied or made available (in whole or in part) to any other person without our prior written express consent. To the fullest extent permitted by law, we do not accept or assume responsibility to anyone other than NESO for this report or for the conclusions we have formed. Deloitte LLP Manchester, United Kingdom 12 March 2026 3 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 2 Background and Context Background 2.1 Electricity Market Reform (“EMR”) is intended, inter alia, to promote investment in low-carbon electricity generation and ensure security of supply. The Capacity Market supports achieving security of electricity supply by providing a payment for reliable sources of capacity. This supplements generators’ electricity revenues, to ensure they deliver energy when needed. This is designed to encourage the investment needed to replace older power stations, provide backup for more intermittent and inflexible low carbon generation sources and support the development of more active demand management in the electricity market. EMR has been implemented through the Energy Act 2013 and the Electricity Capacity Regulations 2014 (as amended) (“the Regulations”). The Capacity Market Rules 2014 (as amended) (“the Rules”) provide the technical and administrative detail for implementing the operating framework set out in the Regulations. As such, the Rules provide a description and procedures regarding the operation of the Capacity Market. National Energy System Operator Limited (NESO) fulfils the role of EMR Delivery Body for the Capacity Market and is responsible for pre-qualifying auction participants, running the capacity auctions, and issuing and monitoring agreements, and for the issuing of Capacity Market notices. Unless otherwise specified herein, words and expressions used in this Report have the same meaning as defined in the Regulations and Rules. Requirement for the Auction Monitor 2.2 In its role as DB for EMR, NESO, pursuant to Chapter 5 of the Rules, is required to appoint a third party to monitor the conduct of each Capacity Auction, referred to as the Auction Monitor. Under the Rules the Auction Monitor is required to provide a report (“Report”) to the Secretary of State for Energy Security and Net Zero (“the SoS”) with a copy to the Gas and Electricity Markets Authority (“the Authority”) which:  Confirms the list of Bidders that should have been awarded a Capacity Agreement;  Sets out whether or not the Auction Monitor considers that the Capacity Market DB and/or the Auctioneer has conducted the Capacity Auction in accordance with the Regulations and the Rules;  If applicable, identifies any actual or potential breach of the Regulations or the Rules or other actual or potential irregularity in the conduct of the Capacity Auction by the Capacity Market DB and/or the Auctioneer; and 4 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026  If applicable, includes a review of the calculations made and the Auction Monitor’s assessment as to the likely consequences of such actual or potential breach or irregularity. Under Rule 5.14.3(a) the Auction Monitor is required to provide the Report to the SoS. This will be achieved through the Auction Monitor providing the Report to the DB who will send it to the SoS and copy the Report to the Authority. We understand the SoS intends to publish this Report. Basis on which work performed 2.3 Deloitte LLP has been engaged by NESO to perform the Auction Monitor role and report on the performance by NESO (in its role as Delivery Body for the 2025 T-4 Auction) by providing a reasonable assurance opinion under the International Standard on Assurance Engagements (“ISAE”) (Revised) 3000 in respect of the requirements for the Auction Monitor. Our independent opinion has been prepared under ISAE 3000, which provides the structure and internationally recognised framework for undertaking the engagement, leading to a formal assurance opinion which is provided in Section 1 of this Report. 5 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 3 Report of Observations Where identified during our work, we also report observations relating to the DB’s compliance with relevant parts of Chapter 5 of the Capacity Market Rules updated 23 June 2025, and the Data and Auction sections of the Capacity Market Auction Guidelines (the ‘Auction Guidelines’) updated on 10 February 2026 as per Regulation 21. We also report on any operational irregularity with respect to the conduct of a Capacity Auction. The following observation is noted for the 2025 T-4 Auction. Table 1. Reported observations for the 2025 T-4 Auction Related CM Rules and Regulations 5.6.5A Effect Recommendation Management should review their Impact Assessment procedures and criteria to ensure the impact of Rules changes in the future fully considers the impact on all aspects of the Auction System calculation. A workaround process was required to be developed to permit Bidders to submit a DBA leveraging the alternate bid submission process and which would have required some manual intervention from the DB had a DBA been submitted. Observation The Auction System is configured to reduce the contract duration for any Duration Bid Amendment to one year (per Rule 5.6.5(b)). The DB’s impact assessment of the change to the Auction Rules described in the Other Matter in section 1.7 above did not identify the potential impact on the application of the Auction Clearing Rules – specifically Rule 5.8.5(c) – if a bid in respect of a Declared Long Stop CMU submitted a DBA. Aside from the matter detailed above, we have no observations to report relating to the DB’s compliance with relevant parts of Chapter 5 of the Capacity Market Rules and the Data and Auction sections of the Capacity Market Auction Guidelines (the ‘Auction Guidelines’). 6 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 4 Confirmation of Bidders to be awarded Capacity Agreements The 2025 T-4 Auction started at 09:00 on 10 March 2026 and the Clearing Round was Round 10, which closed at 16:45 on 10 March 2026. The Clearing Price of the 2025 T-4 Auction was equal to £27.10, with the aggregate Bidding Capacity of Capacity Agreements of 40,108.608 MW. Based on the outcome of the 2025 T-4 Auction and in accordance with the Capacity Market Rules 2014 published on 1 August 2014 (as amended), we confirm that the following list of bidders and corresponding CMUs1 to be awarded Capacity Agreements were successful in the 2025 T-4 Auction. Table 2. List of Bidders and Corresponding CMUs Awarded Capacity Agreements in the 2025 T-4 Auction Name of Applicant per CM Register CM Unit Name per CM Register ADV 005 LIMITED AGR SOLAR 2 LIMITED AGR SOLAR 3 LIMITED AGR SOLAR 4 LIMITED AIK2A SUSTAINABLE ENERGY LTD ALKANE ENERGY UK LIMITED AMPIL 2 ASSET LIMITED Calow Green 3 BFEN29 LHBESS WYBS29 Aikengall IIa Arlesey 4,5,6 Aveley 13, 14 Dogsthorpe HemHea Houghton Main Ling Hall Solar Manvers Markham Rhymney Whitwell VILLA6 1 Bidding Company/Group information is taken from the Capacity Market Register. 7 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register ARDROSSAN WIND FARM (SCOTLAND) LIMITED Ardrossan wind farm BALL GREEN ENERGY STORAGE LIMITED BATTERY BOX LIMITED BaGF28 BT4U28 BT4U29 BT4U30 BT4U31 BT4U32 BT4U33 BT4U34 BT4U37 BT4U39 BT4U40 BEAUFORT WIND LIMITED BGI TRADING LIMITED Lambrigg Wind Farm BGIT01 BICKER FEN WINDFARM LIMITED Bicker Fen wind farm BIG BATTERY (FLATTERTON FARM) LIMITED FLATTERTON BIG BATTERY (HOLMQUARRY ROAD) LIMITED HOLMQUARRY BIG BATTERY (SATURLAND FARM B) LIMITED SATURLAND BIG BATTERY (SHERIFF FAULDS FARM 1) LIMITED SHERIFF FAULDS BLACKDYKE BESS LIMITED BLACKHILLOCK FLEXPOWER LTD BOLNEY GREEN ENERGY HUB 1 LIMITED BOLNEY GREEN ENERGY HUB 2 LIMITED BOLNEY GREEN ENERGY HUB 3 LIMITED NBHAR1 NBHAR2 NBHAR3 NBHAR4 NBHAR5 BLK 4-hour A BLK 4-hour B BLK 4-hour C BLK 4-hour D BGEHL1 BGEHL2 BGEHL3 BOLSHAN RENEWABLES LIMITED BRLR Redhouse 8 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register BRAES OF DOUNE WIND FARM (SCOTLAND) LIMITED Braes of Doune Wind Farm BRING ENERGY LIMITED BRITISH SOLAR RENEWABLES LIMITED BRITISH SUGAR PLC Battersea Dengie BESS BSBX25 BSWX25 BRITNED DEVELOPMENT LIMITED BritNed Interconnector BSSL EAST AYRSHIRE 1 LTD BURTON TOP SOLAR LIMITED BURY POWER LIMITED CAMBRIAN WIND ENERGY LIMITED CAPBAL (BRACO) LIMITED CAPBAL (FORFAR) LIMITED CAPBAL (KILWINNING) LIMITED Inchbean Burton Top Solar BESS Bury Power Limited Cambrian Wind Farm BRAC24 FORF25 KILW25 CARGILL PLC Cargill Manch Generation CARRINGTON POWER LIMITED POL CHP Carrington_1 Carrington_2 CARRINGTON STORAGE LIMITED Carrington Storage Limited CAUSEYMIRE WINDFARM LIMITED Causeymire wind farm CBS ENERGY STORAGE ASSETS UK LIMITED CENTRICA BUSINESS SOLUTIONS (GENERATION) LIMITED CITIGEN (LONDON) LIMITED CLYNE POWER LIMITED COCKENZIE STORAGE B LTD 7RES31 8RES31 10REBE BNDN001 Citigen Clyne Power Limited COB292 COCB29 COLDHAM WINDFARM LIMITED Coldham Windfarm CONRAD (BLETCHLEY) LIMITED Bond Estates Milton Keynes CONRAD (CLEVELEYS) LIMITED Venture Road CONRAD (FLEETWOOD) LIMITED CONRAD (FLITWICK) LIMITED Copse Flitwick 9 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register CONRAD (LYTHAM) LIMITED CONRAD (PUTNOE) LIMITED CONRAD (STEVENAGE A) LIMITED CONRAD (STEVENAGE B) LIMITED CORYTON ENERGY COMPANY, LTD. COWLEY BATTERY STORAGE LIMITED Amy Johnson Way Elms Caswell Cavendish Coryton COWLEY CULVERY POWER LIMITED Culvery Power Limited DAFEN RESERVE POWER LIMITED Dafen Reserve Power Limited DALMARNOCK BESS LTD Dalmarnock BESS DALSWINTON WINDFARM (SCOTLAND) LIMITED Dalswinton wind farm DOUGLAS WEST WIND FARM LTD Douglas West wind farm DRAX POWER LIMITED DRAX PUMPED STORAGE LIMITED DRAX RIVER HYDRO LIMITED DYCE BATTERY STORAGE LIMITED E.ON UK PLC 10 DRAX Unit 10 DRAX Unit 12 DRAX Unit 9 Cruachan Unit 1 Cruachan Unit 2 Bonnington Hydro Carsfad Hydro Drumjohn Hydro Earlstoun Hydro Kendoon Hydro Stonebyres Hydro Tongland Hydro DYCE50 BAD_BIO CE_Aggregated CE_Aggregated 2 CE_Aggregated 3 CE_Monk EON026 EON027 EON028 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register EV_DSR_1 EV_DSR_10 EV_DSR_2 EV_DSR_3 EV_DSR_4 EV_DSR_5 EV_DSR_6 EV_DSR_7 EV_DSR_8 EV_DSR_9 HEY_CHP NPCM-13 EGECL2 EARLS GATE ENERGY CENTRE LIMITED EARLSBURN WIND ENERGY LIMITED Earlsburn Wind Farm EAST LONDON ENERGY LIMITED EATON SOCON POWER LIMITED ELE - KY ELE - SC Eaton Socon EDF ENERGY NUCLEAR GENERATION LIMITED Sizewell B Power Station CMU 1 Sizewell B Power Station CMU 2 EFFICIENT GENERATION LIMITED Aldersgrove EirGrid Interconnector Designated Activity Company EWIC EL PROJECT CO.2 LIMITED ELECLINK LIMITED ENEL X UK LIMITED ENFINIUM FERRYBRIDGE 1 LIMITED ENFINIUM FERRYBRIDGE 2 LIMITED ENFINIUM PARC ADFER LIMITED ENGIE POWER LIMITED 11 Bolton107 ElecLink U26412 U26413 U26414 U26415 U26416 U26417 U26418 U26419 U26420 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register U26421 U26422 U26423 U26424 U26425 U26426 U26427 U26428 U26429 U26430 U26431 U26432 U26433 U26434 U26435 FM1 FM2 Parc Adfer EGENCU EGENGG EGENMX EGENST EGENWX MXDSR1 MXDSR2 UPDR10 UPDR11 UPDR12 UPDR13 UPDR14 UPDR15 UPDR16 12 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register UPDSR1 UPDSR2 UPDSR3 UPDSR4 UPDSR7 UPDSR8 ENRAY SPV 23855 LIMITED Hall Gate Farm Battery Storage ESB SOLAR (NORTHERN IRELAND) LIMITED ESSO PETROLEUM COMPANY,LIMITED EXAGEN HOLLY LANE LTD MillFarm1 EMD254 EMG254 Holly Lane EXCEL DISTRICT ENERGY COMPANY LIMITED EDEC FARR WINDFARM LIMITED FCC (E&M) LIMITED Farr Wind Farm Millerhill EfW FCC BUCKINGHAMSHIRE LIMITED FCC Buckinghamshire Ltd FCC ENVIRONMENT (LINCOLNSHIRE) LIMITED Lincs EFW FENLAND WINDFARMS LIMITED First Hydro Company FLEXION ENERGY HOLDINGS UK LTD FLEXITRICITY LIMITED 13 Deeping wind farm Glass Moor wind farm Red House wind farm Red Tile wind farm D1R254 D3_254 D4_254 D5_254 EL259N iV025C F20112 F20120 F20121 F20122 F20123 F20124 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register F20125 F20126 F20127 F20128 F20129 F20130 F20131 F20132 F20133 F24135 F24136 F24137 F24170 F24171 F24172 F24181 F24182 FLEX10 FLEX11 FLEX12 FLEX13 FLEX153 FLEX158 FLEX162 FLEX163 FLEX166 FLEX169 FLEX30 FLEX66 FLEX67 FLEX77 FLEX81 14 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register FRP MERCIA HOLDCO 2 LIMITED Geddington Road FRP MERCIA HOLDCO LIMITED FRV POWERTEK LIMITED Kestral Road Union Street Dunbar 2 GLASS LEAF POWER LIMITED Glassleaf Power GOWHOLE BATTERY STORAGE LIMITED GPC 1039 LTD GPC 1184 LTD GPC 680 LTD GR RENEWABLES 1 LIMITED GR RENEWABLES 2 LIMITED GR RENEWABLES 3 LIMITED GOWESS Tealing Crookston EastKilbride GR1 - Fibden Farn GR2 - Scalm Park GR3 - Buxton Road GREENLINK INTERCONNECTOR LIMITED Greenlink Interconnector GREENSPAN CONTRACTORS LIMITED Abercorn GREENSPAN NIFTY FIFTY LIMITED GRENERGY RENEWABLES UK LIMITED GRIDBEYOND LIMITED 15 Wardpark Alpha Wardpark Bravo GR - Spring Lane END027 END028 END029 END030 END031 END032 END033 END034 END035 Endeco Technologies CMU1 Endeco Technologies CMU1 Endeco Technologies END014 GB2401 GB2405 GB2408 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register GB2410 GB2411 GB2414 GB2418 GB2419 GB2420 GB2421 GB2422 GB2423 GB2435 - END034 Duplicate GB2436 - END036 Duplicate GB2501 GB2509 GB2510 GB2527 GB2531 GB2547 GB2549 GB2550 GB2551 GB2552 GB2553 GB2555 GB2556 GB2632 GBD004 GBD008 GBD010 GBD011 GBD012 GBD013 GBD020 16 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register GBD022 GBD023 GBD038 GBD039 GBD045 GBD048 / GB2548 GM2611 GM2615 GM2618 GM2619 GM2620 GM2622 GM2623 GM2624 GM2625 GM2626 GM2627 GM2628 GM2629 GN2601 GN2605 GridBeyond GBD009 GX2601 GX2602 GX2603 GX2604 GX2605 GX2606 GX2607 GX2608 GX2609 GX2610 17 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register GWENT FARMERS' COMMUNITY SOLAR PARTNERSHIP LIMITED HARMONY BH LIMITED HARMONY HB (JV) LIMITED HARMONY HS (JV) LIMITED HD000ACT LTD HEIT BD LIMITED HEIT FM LIMITED Hollybush BESS Ltd HULL RESERVE POWER LIMITED IMMINGHAM POWER LIMITED IMPACT POWER LIMITED INDIAN QUEENS POWER LIMITED INOVYN CHLORVINYLS LIMITED GX2611 GX2612 UEN024 UEN037 Llanwern Bramham ESS Humberston ESS Hunself 2029 Iron Acton 3 HBDL29 HFML29 Lando 2 Hull Reserve Power Limited Immingham Power Station EMISTA Indian Queens INOVYN1 MCRUN RuncornERF - Phase 2 INTEGRUM SPV 24002 LIMITED Porch House Farm Battery Storage IQ ENERGY CENTRE LIMITED IQEE01 IRWELL POWER LIMITED KEADBY GENERATION LIMITED KENT ENVIROPOWER LIMITED KENT RENEWABLE ENERGY LIMITED Irwell Power Limited Keadby 1 and GT3 FCCAL4 KENTRE KILMARNOCK ENERGY CENTRE LIMITED Kilmarnock Energy Centre Limited KILMARNOCK FLEXPOWER LTD KILN POWER LIMITED KINTORE ESS LTD KMS29B KMS29C KMS29D Kiln Power Limited ESX477 LAKESIDE ENERGY FROM WASTE LIMITED Lakeside EFW 18 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register LEATHERHEAD BESS LTD Leatherhead 2025 Updated LEVELISE LIMITED LG-B-50A LIMITED LIGHTSOURCE SPV 191 LIMITED LEVC09 BEAUL1 PENTIR LISSETT AIRFIELD WIND FARM LIMITED Lissett wind farm LISTER BATTERY LTD LSTB29 LITTLE CHEYNE COURT WIND FARM LIMITED CMU_LCCW-1 LITTLE STAUGHTON AIRFIELD SOLAR LIMITED Staughton LOCH FERGUS SOLAR LTD LODDON POWER LIMITED Ferg00 Loddon Power Limited LOSTOCK SUSTAINABLE ENERGY PLANT LTD Lostock Sustainable Energy Plant MACDUFF BATTERY STORAGE LIMITED MACD50 MARDEN POWER LIMITED MAS 009 LIMITED Marden Power Limited Ipswich Road MERCIA WASTE MANAGEMENT LIMITED Mercia Waste Management Ltd MINSCA WINDFARM (SCOTLAND) LIMITED Minsca wind farm MOOR ISLES FARM ENERGY STORAGE LIMITED MI0001 MOYLE INTERCONNECTOR LIMITED Moyle Interconnector MYNYDD CLOGAU WINDFARM LIMITED Mynydd Clogau wind farm NATIONAL GRID IFA 2 LIMITED NATIONAL GRID INTERCONNECTORS LIMITED NATIONAL GRID NORTH SEA LINK LIMITED NATIONAL GRID VIKING LINK LIMITED NEMO LINK LIMITED NEUCONNECT BRITAIN LTD IFA225 IFA_25 NSL_25 VIK_25 NEMOGB neucon NEWLINCS DEVELOPMENT LIMITED NEWLINCS IWMF NEXTPOWER BOSWORTH LIMITED NEXTPOWER GRANGE LIMITED NEXTPOWER HIGH GARRETT LIMITED Bosworth The Grange High Garrett NEXTPOWER LOWER STRENSHAM LIMITED Lower Strensham NEXTPOWER SOUTH LOWFIELD LIMITED South Lowfield NORTH HOYLE WIND FARM LIMITED North Hoyle Wind Farm Limited 19 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register NORTHUMBERLAND ENERGY RECOVERY LTD STV Line 3 EfW NORTHWICH POWER LIMITED Northwich Power Limited Nuclear Decommissioning Authority Maentwrog Hydro-electric Power Station NURSLING ENERGY TWO LIMITED OCTOPUS ENERGY LIMITED Nurse2 OCT090 OCT091 OCT092 OCT093 OCT094 OCT095 OCT096 OCT097 OCT098 OCT099 OCT100 OCT101 OCT102 OCT103 OCT104 OCT109 OCT110 OCT111 OCT114 OGMORE POWER LIMITED OSSPV001 LIMITED P3P BREHON LIMITED Ogmore Power Limited OEL CM 01 Europa Energy Centre P3P ENERGY MANAGEMENT AE LIMITED Woodhouse Energy Centre Palm Paper Limited PD100NIN LTD PEAK GEN POWER LIMITED 20 Palm Paper CHP Palm Paper DIP Ninfield COV-24 DID-24 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register PERSLEY ENERGY STORAGE LIMITED PIVOTED POWER LLP PRII ENERGY LIMITED PRIORY GENERATION LIMITED PYEBRIDGE POWER LTD RHYL FLATS WIND FARM LIMITED RIVER NENE POWER LIMITED HAT-24 HAY-24 PERS28 Pivot Power Cowley Pivot Power Kemsley PRII11 Priority Gen MAPB25 CMU_RHYW-1 Peterborough Power RIVERSIDE RESOURCE RECOVERY LIMITED RRRF01 ROCKSAVAGE POWER COMPANY, LTD. Rocksavage ROWAN ONSHORE WINDFARMS LIMITED Broomhill Wind Farm High Hedley 2 Langley Wind Farm Longpark Wind Farm Walkway Wind Farm CMU_BRAE-1 CMU_CHEGT1 CMU_COWE1 CMU_COWE2 CMU_CWMD-1 CMU_DIDC1G CMU_DIDC2G CMU_DIDC3G CMU_DIDC4G CMU_DIDCB5R CMU_DIDCB6R CMU_DOLGH-1 CMU_DOLGL-1 CMU_DOUG-1 CMU_GROG-1 RWE GENERATION UK PLC 21 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register CMU_GYAR-1R CMU_HDAG-1 CMU_HDCG-1 CMU_HDDI-1 CMU_HYTHE CMU_INVL-1 CMU_LBAR-1R CMU_PEMB-11R CMU_PEMB-21R CMU_PEMB-31R CMU_PEMB-41R CMU_PEMB-51R CMU_RIVE-1 CMU_STAY-1R CMU_STAY-2R CMU_STAY-3 CMU_STAY-4R RWE RENEWABLES UK ONSHORE WIND LIMITED CMU_STGW-1 RWE RENEWABLES UK ROBIN RIGG WEST LIMITED CMU_RRWW-1 RWE RENEWABLES UK SOLAR AND STORAGE LIMITED CMU_ASHB-1 SALTEND COGENERATION COMPANY LIMITED Saltend Unit 1 CMU_RASB-1 Saltend Unit 2 Saltend Unit 3 SALTHOLME SOUTH POWER LIMITED Saltholme South Power Limited SCOTTISHPOWER RENEWABLES (UK) LIMITED Black Law Windfarm Clachan Flats Wind farm Greenknowes Windfarm Hagshaw Hill Extension Whitelee I Windfarm RUBY25 Seabank 1 SE RIGIFA BESS LTD SEABANK POWER LIMITED 22 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register SECURE GENERATION LIMITED SEVERN POWER LIMITED SG GRI TILN BESS LIMITED SHEAF ENERGY LIMITED SIMEC LOCHABER HYDROPOWER 2 LIMITED Seabank 2 Melrow Severn Unit 10 Severn Unit 20 TILN28 SEL2T4 SLH2G1 SLH2G2 SLH2G3 SLH2G4 SLH2G5 SOUTH KYLE WIND FARM LIMITED South Kyle Wind Farm Limited SOUTH PARK FARM ENERGY CENTRE LIMITED South Park Energy Farm SOUTH TYNE & WEAR ENERGY RECOVERY LTD STV Lines 4 & 5 EfW SPALDING ENERGY COMPANY, LTD. Spalding SPARK STEAM LIMITED SSE ENERGY SUPPLY LIMITED SSE GENERATION LIMITED 23 Spark Steam Energy Centre Marchwood Allt Na Lairgie Artfield Fell Beauly Cassley Ceannacroc Chliostair Clachan 1 Clunie Cuaich Cuileig Culligran Dalchonzie Deanie 1 Deanie 2 Drumderg 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register Errochty 1 Errochty 2 Errochty 3 Fasnakyle 1 Fasnakyle 2 Fasnakyle 3 Fasnakyle Compset Finlarig Foyers Falls Gaur Glenmoriston Grudie Bridge Invergarry Kerry Falls Killin Kilmelford 1 Kingairloch Lednock Loch Dubh Loch Ericht Loch Gair Lochay 1 Lochay 2 Luichart Lussa Mossford Mullardoch Nant North Renewables Nostie Bridge Orrin Quoich 24 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register Rannoch 1 Rannoch 2 Rannoch 3 Shin Sloy 1 Sloy 2 Sloy 3 Sloy 4 South Renewables Sron Mor St Fillans Storr Lochs Striven Torr Achilty Tummel 1 Tummel 2 West Renewables SSE RENEWABLES WIND FARMS (UK) LIMITED Hadyard Hill ST ASAPH POWER LIMITED ST FERGUS ENERGY LIMITED St Asaph Power Limited St Fergus Energy Park ST OWENS CROSS BATTERY STORAGE LIMITED OWENS0 STATKRAFT UK LTD Generator 1 of the Rheidol Hydro Electric Power Plant Generator 2 of the Rheidol Hydro Electric Power Plant Generator 3 of the Rheidol Hydro Electric Power Plant SUEZ RECYCLING AND RECOVERY KIRKLEES LTD Kirklees EfW SUEZ RECYCLING AND RECOVERY SUFFOLK LTD Suffolk EfW SUEZ RECYCLING AND RECOVERY UK LTD Bolton TRF SUSI EELPOWER ROCK FARM LIMITED SUSI EELPOWER WINCHESTER LIMITED ROCK18 WINP18 SUTTON BRIDGE POWER GENERATION Sutton Bridge STV Lines 1 and 2 EfW 25 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register SUTTON POWER LIMITED TOFTINGALL WIND LIMITED TWENTYSHILLING LIMITED UK POWER RESERVE LIMITED UKGEA 1 LIMITED UNIPER UK LIMITED VEOLIA UK LIMITED 26 Sutton Manor TOFTHL Twentyshilling Wind Farm Aberdare Power Station Bridgwater Power Station Cowley Hill Power Station Greengate Power Station Sevington Power Station Solutia Power Station South Cornelly Power Station UKGEA CDC Connahs U1 Connahs U3 Enfield Grain GT-1 Grain GT-4 Grain U6 Grain U7 Grain U8 Holford DSR Killingholme Module 1 Killingholme Module 2 Taylor's Lane GT2 Taylor's Lane GT3 Chineham ERF Marchwood ERF Newhaven ERF Portsmouth ERF Staffordshire ERF Tyseley ERF VEOLIA CHP UNIT B 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register VEOLIA CHP UNIT C VEOLIA CHP UNIT D VEOLIA CHP UNIT E VEOLIA CHP UNIT F VEOLIA CHP UNIT K VEOLIA CHP UNIT L VEOLIA CHP UNIT M VEOLIA CHP UNIT N VEOLIA CHP UNIT P VEOLIA CHP UNIT Q VEOLIA CHP UNITS A VEOLIA CHP UNITS I VEOLIA CHP UNITS J Cardiff ERF Exeter ERF Immingham CHP 1 Immingham CHP 3 Damhead Creek Rye House Shoreham Southampton VIRIDOR ENERGY LIMITED VPI Immingham LLP VPI POWER LIMITED W4B RENEWABLE ENERGY LIMITED WARRINGTON POWER LIMITED Warrington Power Limited WATTSERVE LTD WEST BURTON B LIMITED WATT29 West Burton B Power Station CMU 1 West Burton B Power Station CMU 2 West Burton B Power Station CMU 3 WHARF POWER LIMITED Wharf Power Limited WHITEHILL BATTERY STORAGE LIMITED WHL200 WHITETOWER ENERGY LIMITED 27 Croydon Power Exeter Power Heartlands Power Heartlands Power 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register WINDY RIG WIND FARM LIMITED Windy Rig wind farm WOLVERHAMPTON POWER LTD Wolverhampton Power Ltd Thornhill OCGT Viking Power ZENOBE RENTAL 12 LIMITED 28 DSR352 DSRUU4 EVZ100 EVZ101 EVZ102 EVZ103 EVZE65 EVZE77 EVZE78 EVZE79 EVZE82 EVZE83 EVZE84 EVZE85 EVZE86 EVZE87 EVZE88 EVZE89 EVZE90 EVZE91 EVZE92 EVZE93 EVZE94 EVZE95 EVZE96 EVZE97 EVZE98 EVZE99 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Name of Applicant per CM Register CM Unit Name per CM Register ZEPHYRUS GREEN ENERGY LTD Strathallan Wind Farm EVZEN1 EVZEN4 FVZEN2 29 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Appendix A – In-scope Capacity Market Rules (Chapter 5) The following Rules included in Chapter 5 of the Capacity Market Rules were considered in performing the assurance work.  Rule 5.3 on the ability of qualified parties to participate in the Capacity Auction  Rule 5.4 on CMUs excluded from the Capacity Auction  Rules 5.5.1 to 5.5.4 and 5.11 on the scheduled timing and duration of the Capacity Auction  Rules 5.5.5 to 5.5.9 on the Capacity Auction format and starting price  Rule 5.5.10 on the publication of pre-auction information  Rules 5.5.11 to 5.5.13 on Demand Side Response CMUs and Bidding Capacity  Rules 5.5.14 to 5.5.17 on the consistency of the register with the pre- qualified parties  Rules 5.5.18 and 5.5.20 on the information provided in each round by Auctioneer  Rule 5.5.21 on the use of backup systems during the Capacity Auction  Rules 5.6 to 5.9 on the calculation of the Capacity Auction results  Rule 5.10 on the list of bidders to be awarded Capacity Agreements  Rule 5.14 on the Auction Monitor role 30 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Appendix B – Outline of Work Performed The specific procedures performed were as follows. Table 1. List of Procedures Performed Ref CM Rule Independent checks 1 n/a 2 n/a Check that the version of the Auction System used in the Auction is the same version accepted following User Acceptance Testing (UAT). Check that security controls are in place to prevent unauthorised access to the Auction System.  Confirm that all users are required to have a password and PIN.  Confirm from the audit log that all authorised individuals that viewed the CMUs of an organisation were associated to that organisation.  Confirm that management’s system testing included consideration of security processes. 3 5.3 Check that those Bidders and CMUs that were allowed to participate in the Capacity Auction had the correct access and information loaded on to the Auction System by:  Obtaining a register of qualifying CMUs, with their relevant features, which intend to participate in the Capacity Auction.  Comparing the register to the list of CMUs on the Auction System and confirming that there have been neither additions to nor omissions from the list.  Liaising with the Auctioneer throughout the Auction as to whether they have identified any disqualified CMUs and, if so, confirming that these have been treated as required by Rule 5.3.3. 4 5.4 Check that excluded CMUs do not have access to the Auction System by:  Obtaining list of CMUs that have been withdrawn from a Capacity Auction and register of qualifying CMUs.  Comparing the register to list of CMUs on the Auction System and confirming that those CMUs that have been withdrawn are not included in the Auction System, or that their ability to submit an Exit Bid has been withdrawn. 5 5.5.1 – 5.5.4 5.11 (if applicable) Check on the timing and duration of the Capacity Auction by:  Confirming that the Capacity Auction was held on the date specified in the Auction  Guidelines, with minimal delays. If the Auction was not completed within 5 working days of the first Bidding Window, confirming that the Secretary of State was notified by the Auctioneer. 6 5.5.5 – 5.5.9 Check that the Capacity Auction was run in line with Rules 5.5.5 to 5.5.9 by:  Confirming that the Capacity Auction was run in a manner aligned with the Rules: on a descending clock basis, with a series of price spread Bidding Rounds, with decrements determined by a process issued by the Secretary of State to the Auctioneer, concluding only once the Capacity Auction clears.  Confirming that these spreads are expressed as a range from the Bidding Round Price Cap to the Bidding Round Price Floor, and that the Bidding Round Price Cap of the first round is equal to the Price Cap for the Auction.  Confirming that the price cap for round n+1 is equal to price floor to round n for all rounds as per Rule 5.5.7.  Reproducing the calculation of Clearing Price and the aggregate Bidding Capacity at the Clearing Price.  Check the auctioneer informed the delivery body of the Excess Capacity Rounding Threshold at least 20 days working days before the Auction. 31 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Ref CM Rule Independent checks 7 5.5.10 8 9 5.5.11 – 5.5.13 5.5.14 – 5.5.17 Check that, at least 15 Working Days before the first Bidding Round, the Delivery Body published the date and time on which the Capacity Auction would start, the identity, the Excess Capacity Rounding Threshold and De-rated Capacity of all Prequalified CMUs, and the identity of the Auction Monitor. Check that, for each Demand Side Response CMU (DSR CMU), Bidding Capacity equals De-rated Capacity unless the DSR CMU nominated a lower capacity at least 10 Working Days before the first Bidding Window. Check that the correct information for Prequalified New Build CMUs, Refurbishing CMUs and DSR CMUs has been correctly uploaded to the IT Auction System by:  Confirming that the register provided for Rule 5.3 only includes those Prequalified New Build CMUs, Refurbishing CMUs and DSR CMUs that confirmed their intention to participate in the Capacity Auction between 15 and 10 Working Days before the first Bidding Window.  Confirming that the features contained in the register include the duration of Capacity Agreements at the Price Cap for New Build CMUs and Refurbishing CMUs.  Confirming that the system has recorded both the Refurbishing CMU and the Pre- Refurbishment CMU for any Applicant which confirmed that it wanted to participate with its Pre-Refurbishment CMU. 10 5.5.18, 5.5.20 Check that the running of the Auction was in line with the Rules, namely:  For each round that is not the first bidding round, the Auctioneer announced the Bidding Round Price Spread, the Clearing Capacity at the Bidding Round Price Floor, and the Excess Capacity to the nearest Excess Capacity Rounding Threshold (or if the Excess Capacity is below this, the Auctioneer announced that the Excess Capacity is below 1 GW) at the start of the round.  For each round Excess Capacity at price floor was calculated and displayed correctly on the Auction system for each round in line with 5.5.18.  For each round the Auctioneer specified in advance the time that the Bidding Round would begin and end. Check that backup systems are in place to submit bids and that these include safeguards to ensure that the correct bid is submitted. Observe and confirm with the Auctioneer whether the backup systems have been used to submit bids during the Capacity Auction. Review log of calls made/received by the Auctioneer during the Auction. Independently reapply the relevant Capacity Market Rules to calculate the Capacity Auction clearing price and confirm the identification of each CMU to be awarded a Capacity Agreement.  Obtain full details of Exit Bids and Duration Bid Amendments from Delivery Body.  Confirmed that any Duration Bid Amendments submitted in relation to Declared  Long Stop CMUs were submitted in line with the alternative procedure defined by the DB. Independently reapply the Rules, as detailed within the Capacity Market Rules 2014 (as amended), and compare the results to those calculated by the Delivery Body. To minimise differences, use the random number generated by the Delivery Body in the case of a tie-break. If differences are identified in the results, review with the Delivery Body and obtain explanations for these differences.  Review Auction System UAT to check the random number process that is applied for the Auction. Confirm that the DB has notified Bidders and the SoS of the provisional results.Confirm that the DB has published the provisional clearing price and the provisional aggregated Bidding Capacity of Capacity Agreements awarded within 24 hours of the auction clearing. Confirm that the agreement length has been correctly recorded for any Declared Long Stop CMUs which submitted Duration Bid Amendments. Compare the results provided by the DB to the Bidders and the SoS and published to the results of our independent reapplication of the Rules from the previous procedure. Obtain explanations for any differences. 11 5.5.21 12 5.6 – 5.9 13 5.10 32 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Ref CM Rule Independent checks 14 5.14 Confirm read-only access has been provided to the Auction System for the Auction Monitor throughout the Capacity Auction. Document details of any discussion with Delivery Body of any potential breach identified by the Auction Monitor. Document details of any views expressed by the Auction Monitor following a request by the Delivery Body. Review the pages accessed by those accessing the auction remotely. 33 2025 four year ahead Capacity Auction (T-4) Delivery Year 2029/30 Deloitte LLP 12 March 2026 Other than as stated below, this document is confidential and prepared solely for your information and that of other beneficiaries of our advice listed in our engagement letter. 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