Slow Reserve | National Energy System Operator
Summary
NESO has issued the Go-Live Notice for Slow Reserve service, opening the Enduring Auction Capability (EAC) auction on 17 March with the first auction on 31 March 2026. This triggers the end of STOR service at 05:00 on 1 April 2026. Slow Reserve provides frequency management through post-fault energy balancing, requiring units to respond within 15 minutes with minimum 1MW capability.
Why it matters
This completes the reserve services reform, replacing STOR with a co-optimised auction platform that prices reserve alongside other balancing services. The reform shifts from bilateral STOR contracts to competitive day-ahead auctions, as such creating price discovery for reserve services that was previously absent.
Key facts
- •Go-Live Notice issued 16 March 2026
- •EAC auction opens 17 March at 08:00
- •First auction 31 March 2026 at 14:00
- •STOR ends 1 April 2026 at 05:00
- •15-minute response requirement
- •1MW minimum capacity threshold
- •Co-optimised with Quick Reserve, Dynamic Response, and Balancing Reserve
Timeline
Areas affected
Related programmes
Memo
What changed
NESO issued the Go-Live Notice for Slow Reserve on 16 March 2026, triggering the opening of the Enduring Auction Capability (EAC) auction on 17 March at 08:00. The first Slow Reserve auction runs on 31 March 2026 at 14:00, ending STOR service at 05:00 on 1 April 2026. This implements Ofgem's decision from 9 October 2025 approving NESO's proposed Service Terms and Procurement Rules for the new reserve service.
Slow Reserve provides post-fault energy balancing to restore frequency imbalances to ±0.2Hz within 15 minutes of generation or demand loss events. The service operates through co-optimised day-ahead auctions alongside Quick Reserve, Dynamic Response, and Balancing Reserve, replacing STOR's bilateral contracting model with competitive price discovery.
What this means in practice
Service specifications: Units must deliver minimum 1MW capacity change within 15 minutes. Positive Slow Reserve increases generation or decreases demand; Negative Slow Reserve does the opposite. The service accepts both Balancing Mechanism (BM) and non-BM participants, requiring 15-second performance metering data (1-second acceptable) through NESO's operational metering architecture.
Market structure: The EAC platform runs single daily auctions covering all co-optimised reserve services. This creates transparent pricing where STOR previously operated through opaque bilateral deals. Providers submit availability declarations and receive dispatch instructions through NESO's Open Balancing Platform (OBP) web services for non-BM units, while BM units use existing interfaces.
Transition arrangements: Positive Slow Reserve includes "linked windows" during an initial transitional period as NESO embeds the enduring service design. STOR contracts terminate automatically when Slow Reserve launches, with no overlap period. Contract transfers between units require notification to five NESO email addresses using the published template.
Technical requirements: Non-BM providers must integrate with OBP systems supporting Physical Notification, Availability, Heartbeat, and Dispatch/Cease Instruction services. All providers need performance metering capabilities delivering data every 15 seconds with specified file structures. BM providers only require performance metering integration beyond existing arrangements.
What happens next
Immediate implementation: Mock auctions began during February 2026 to test systems and provider readiness. NESO held drop-in sessions on 26 February and 12 March, plus a final webinar on 4 March covering requirement setting, technical specifications, and onboarding procedures.
Operational timeline: The auction opens for bidding at 08:00 on 17 March, with results determining service provision from 1 April 2026. STOR service provision ends at 05:00 on 1 April, creating a clean transition without service gaps. NESO publishes requirement forecasts through its Data Portal to support bidding decisions.
Ongoing requirements: Providers must complete unit registration in the Single Market Platform (SMP) before participation. Contract transfers require advance notification through established procedures. Performance monitoring operates continuously through the metering architecture, with NESO validating that declared capacity doesn't exceed pre-qualified levels.
Regulatory framework: This completes the reserve services reform initiated through NESO's consultation process and Ofgem's regulatory approval. The co-optimised auction mechanism represents the final implementation of competitive procurement across all reserve products, replacing legacy bilateral arrangements with transparent market-based pricing. BSUoS charges fund the service with costs allocated to all system users based on demand volumes.
The reform fundamentally changes reserve procurement from bilateral negotiation to competitive auctions, creating price transparency and efficiency gains through co-optimisation across multiple balancing services. Providers gain access to a liquid market for reserve services while NESO obtains cost-effective frequency management tools for the increasingly complex electricity system.
Source text4,854 words
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Slow reserve Add to favourites Close tooltip Sign in to add this page to your favourites [Sign in or register](/saml-login) Show favourites Close Close tooltip Sign in or register to manage your favourites [Sign in or register](/saml-login) [Help](https://www.neso.energy/help-centre) ###### In this section * [BM start up](/industry-information/balancing-services/reserve-services/bm-start) [BM start up](/industry-information/balancing-services/reserve-services/bm-start) Back [BM start up](/industry-information/balancing-services/reserve-services/bm-start) [View](/industry-information/balancing-services/reserve-services/bm-start) * [Balancing Reserve](/industry-information/balancing-services/reserve-services/balancing-reserve) [Balancing Reserve](/industry-information/balancing-services/reserve-services/balancing-reserve) Back [Balancing Reserve](/industry-information/balancing-services/reserve-services/balancing-reserve) [View](/industry-information/balancing-services/reserve-services/balancing-reserve) * [Fast Reserve](/industry-information/balancing-services/reserve-services/fast-reserve) [Fast Reserve](/industry-information/balancing-services/reserve-services/fast-reserve) Back [Fast Reserve](/industry-information/balancing-services/reserve-services/fast-reserve) [View](/industry-information/balancing-services/reserve-services/fast-reserve) * [Short-term Operating Reserve (STOR)](/industry-information/balancing-services/reserve-services/short-term-operating-reserve-stor) [Short-term Operating Reserve (STOR)](/industry-information/balancing-services/reserve-services/short-term-operating-reserve-stor) Back [Short-term Operating Reserve (STOR)](/industry-information/balancing-services/reserve-services/short-term-operating-reserve-stor) [View](/industry-information/balancing-services/reserve-services/short-term-operating-reserve-stor) * [Super SEL](/industry-information/balancing-services/reserve-services/super-sel) [Super SEL](/industry-information/balancing-services/reserve-services/super-sel) Back [Super SEL](/industry-information/balancing-services/reserve-services/super-sel) [View](/industry-information/balancing-services/reserve-services/super-sel) * [Slow reserve](/industry-information/balancing-services/reserve-services/slow-reserve) [Slow reserve](/industry-information/balancing-services/reserve-services/slow-reserve) Back [Slow reserve](/industry-information/balancing-services/reserve-services/slow-reserve) [View](/industry-information/balancing-services/reserve-services/slow-reserve) * [Quick reserve](/industry-information/balancing-services/reserve-services/quick-reserve) [Quick reserve](/industry-information/balancing-services/reserve-services/quick-reserve) Back [Quick reserve](/industry-information/balancing-services/reserve-services/quick-reserve) [View](/industry-information/balancing-services/reserve-services/quick-reserve) * [Future reserve services](/industry-information/balancing-services/reserve-services/future-reserve-services) [Future reserve services](/industry-information/balancing-services/reserve-services/future-reserve-services) Back [Future reserve services](/industry-information/balancing-services/reserve-services/future-reserve-services) [View](/industry-information/balancing-services/reserve-services/future-reserve-services)  ## You are now signed in Visit My NESO account to view and manage your dataset subscriptions. Maybe later [Go to your account](/user/dashboard) # Slow Reserve  ## Project Update 16 March 2026 NESO have published the formal [Go-Live Notice](https://www.neso.energy/document/378736/download) for the Slow Reserve (SR) service. As a result, the EAC auction will open on Tuesday 17th March at 08:00, with the first auction set to run at 14:00 on 31st March, as previously communicated. Please note, this will also trigger the end of the STOR service at 05:00 1st April 2026, as set out in the Slow Reserve Transition Plan. Reserve is needed for frequency management when there is an imbalance between supply of energy and demand for energy. When instantaneous supply is not enough to meet the demand, the frequency falls; where supply outstrips demand, the frequency rises. Additional generation or demand is needed to re-establish this balance. Initially, this is provided by Frequency Response which initiates automatically according to system frequency. Reserve is then instructed to replace the energy delivered by frequency response in accordance with system requirements. Slow Reserve (SR) is primarily aimed at reacting to post-fault disturbances to restore energy imbalances to +/- 0.2Hz within 15 minutes of a loss event (generation or demand). For Negative Slow Reserve (NSR), units are instructed to increase demand or decrease generation in full within 15 minutes. The inverse is true for Positive Slow Reserve (PSR). Slow Reserve is open to any technology with the ability to provide a net change in demand/generation of at least 1MW. Further enquiries: Email: [[email protected]](/cdn-cgi/l/email-protection#62000d1a4c0417161710070d0400030e030c010b0c05110710140b010711220c07110d4c070c0710051b) ## Slow Reserve Requirement Forecast Please find a link to the published Requirement Forecast for both positive and negative Slow Reserve on the NESO Data Portal. [Slow Reserve Requirement Forecast](https://www.neso.energy/data-portal/slow-reserve-requirement-forecast/slow_reserve_requirement_forecast) ## How to Participate [How to Participate](#How-to-Participate) [IT Integrations](#IT-Integrations) [Technical requirements](#Technical-requirements) [Document library](#Document-library) [Latest news](#Latest-news-) [Past events](#Past-events) How to Participate IT Integrations Technical requirements Document library Latest news Past events How to Participate Legal Documents Service Documents Unit Registration Auction Info Contract Transfers Legal Documents Service Documents Unit Registration Auction Info Contract Transfers ## Service Terms and Procurement Rules | [Name](?order=title&sort=asc "sort by Name") | | --- | | [Slow Reserve Go-Live Notice](/document/378736/download) | | [Slow Reserve Service Terms](/document/369916/download) | | [Slow Reserve Procurement Rules](/document/369921/download) | | [Balancing Service Glossary General Terms](/document/346591/download) | Legal Documents ## Service Design and Guidance | [Name](?order=title&sort=asc "sort by Name") | | --- | | [Slow Reserve Linking Notice](/document/377621/download) | | [Slow Reserve Guidance Document](/document/375811/download) | | [Slow Reserve Transition Plan](/document/370841/download) | | [Slow Reserve Service Design](/document/369961/download) | | [Slow Reserve Crossover Guidance](/document/360656/download) | ## Linked Window Guidance We can now share a further update on the go-live of the new Slow Reserve service, with full details of the requirement for linked windows (positive SR only) which will be in place for an initial transitional period as we embed the enduring SR service. Please refer to our [Slow Reserve Transition Plan](https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.neso.energy%2Fdocument%2F370841%2Fdownload&data=05%7C02%7CAdrian.Sellar%40neso.energy%7C367ad68d910045586ea308de17baabee%7Ca63c9e9eb4db442aa94f08718d788e8c%7C0%7C0%7C638974287663301881%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=J22rN%2Fg62%2FJu%2BKtbaEN0Hn%2F61K%2BWCq%2BRcCOqDyAijhk%3D&reserved=0 "https://gbr01.safelinks.protection.outlook.com/?url=https%3a%2f%2fwww.neso.energy%2fdocument%2f370841%2fdownload&data=05%7c02%7cadrian.sellar%40neso.energy%7c367ad68d910045586ea308de17baabee%7ca63c9e9eb4db442aa94f08718d788e8c%7c0%7c0%7c638974287663301881%7cunknown%7ctwfpbgzsb3d8eyjfbxb0eu1hcgkionrydwusilyioiiwljaumdawmcisilaioijxaw4zmiisikfoijoitwfpbcisilduijoyfq%3d%3d%7c0%7c%7c%7c&sdata=j22rn%2fg62%2fju%2bktbaen0hn%2f61k%2bwcq%2brccoqdyaijhk%3d&reserved=0") and Linked Windows Guidance below for full details. [Watch recording](https://players.brightcove.net/6415851838001/default_default/index.html?videoId=6386696094112) [Download slides](https://www.neso.energy/document/374926/download) To participate in Slow Reserve your asset/unit will need to be registered in the Single Market Platform (SMP). [Register](https://www.neso.energy/industry-information/balancing-services/single-markets-platform) The Enduring Auction Capability (EAC) Market design Explainer can be downloaded. [Download EAC Explainer](https://www.neso.energy/document/277671/download) | [Name](?order=title&sort=asc "sort by Name") | | --- | | [SR Mock Auction Guidance](/document/375386/download) | Rich text Service Providers holding a Slow Reserve contract and wishing to transfers obligations to another unit should complete and submit the request to all of the following addresses : * [[email protected]](/cdn-cgi/l/email-protection#e4878b89898196878d8588ca8b94819685908d8b8aa48a81978bca818a8196839d) * [[email protected]](/cdn-cgi/l/email-protection#f3908781c2dd90908792b39d96809cdd969d9681948a) * [[email protected]](/cdn-cgi/l/email-protection#dab9aea8ebf4b9bfa9bf9ab4bfa9b5f4bfb4bfa8bda3) * [[email protected]](/cdn-cgi/l/email-protection#8eedfafcbfa0ede1fde3cee0ebfde1a0ebe0ebfce9f7) * [[email protected]](/cdn-cgi/l/email-protection#54372026667a373b3139143a31273b7a313a3126332d) Please ensure all template instructions are followed. | [Name](?order=title&sort=asc "sort by Name") | | --- | | [Slow Reserve Contract Transfer Template](/document/370106/download) | IT Integrations Please find supporting documentation below to support IT integrations for the Slow Reserve service. Please note, whilst all of the IT Integration material in this section is applicable to non-BM participation, only the Performance Metering documentation is relevant to BM service providers. OBP Documentation Operational Metering Performance Metering Technical Onboarding Webinar OBP Documentation Operational Metering Performance Metering Technical Onboarding Webinar ## OBP Documentation We have released version 1.3 of the OBP Web Service Specification for non-BM service providers, together with WSDL files that formally define the interface between service providers and the OBP application. The documents specify the Quick and Slow Reserve services, which include: * Physical Notification service * Availability service * Heartbeat service * Dispatch/Cease Instruction service In addition to the API documentation, NESO has issued a unified Business Logic Document (BLD) version 1.0 for both Quick Reserve (QR) and Slow Reserve (SR), offering guidance for non-BM providers of both contracted and optional services. The BLD applies equally to QR and SR services. A new validation has been introduced to ensure that declared capacity does not exceed pre-qualified capacity; if it does, NESO will reject it. The BLD outlines the business rules and exceptions for the API, which Quick Reserve and Slow Reserve service providers must implement. It includes the following: * Availability Service: Validation NESO applies to information from providers. * Availability Confirmation: Validation NESO expects providers to apply to information from NESO. * Dispatch/Cease Service: Validation NESO expects providers to apply to information from NESO. * Dispatch/Cease Confirmation Service: Validation NESO applies to Dispatch/Cease information from providers. * Heartbeat Service: Validation NESO applies to information from providers. * Heartbeat Negative Acknowledgement (NACK): Validation NESO expects providers to apply to information from NESO. * Physical Notification: Validation NESO applies to information from providers. * Physical Notification Confirmation: Validation NESO expects providers to apply to information from NESO. ## Documents | [Name](?order=title&sort=asc "sort by Name") | | --- | | [OBP non-BM Reserve Business Logic Document](/document/370166/download) | | [Technology Stakeholder Focus Group July 2025 Slides](/document/366116/download) | | [OBP WSDL](/document/360691/download) | | [OBP Web Services Specifications - v4](/document/360686/download) | Rich text This document describes the operational metering architecture that NESO has in place to enable non-BM participation in Slow Reserve. | [Name](?order=title&sort=asc "sort by Name") | | --- | | [NESO Operational Metering Overview](/document/377676/download) | | [NESO Operational Metering Architecture](/document/347831/download) | | [Guidance on Operational Metering Testing](/document/363986/download) | This document describes the proposed solution for NESO to accept and store Slow Reserve Performance Metering data from individual Service Providers (SPs). Please note this is applicable to both BM and non-BM participation. The requirement for Slow Reserve Performance Metering Data for BM and NBM units at a granularity of every 15-seconds however second-by-second metering is also acceptable. The interface data and transmission requirements that service providers must meet are also outlined, describing the concept of operations for the interface, defining the message structure and protocols that govern the interchange of data, and identifying the communication paths from which NESO expects data to flow. The intended audience of this document are external service providers and internal teams across NESO that are associated with development and operations of the systems connected to the interface. The data design specification provides the following information: * a general description of the interface * data specifications including source, target and validation details, data formats and classification * a description of the transport characteristics including transfer, data exchange, interface processing requirements, flow control and security * assumptions and outstanding questions Also published are two sample files to provide an example of the required data structure, one for 15-second metering files and the other for 1-second metering files. | [Name](?order=title&sort=asc "sort by Name") | [Published](?order=field_publication_date&sort=asc "sort by Published") | | --- | --- | | [Slow Reserve - Performance Metering Data](/document/362276/download) | 5 Jun 2025 | | [Sample File - Performance Metering File Structure - 1 second](/document/362286/download) | 5 Jun 2025 | | [Sample File - Performance Metering File Structure - 15 seconds](/document/362281/download) | 5 Jun 2025 | ## Technical Onboarding Webinar Slow Reserve Technical Onboarding Webinar 6 November 2025 Following the webinar held on 6 November 2025, we have shared the slides and a recording of the webinar. [Watch the webinar](https://players.brightcove.net/6415851838001/default_default/index.html?videoId=6384782706112) [Download the slides](https://www.neso.energy/document/371506/download) Technical requirements We have now completed our initial proposed service and procurement design for the new Slow Reserve service, incorporating both BM (Balancing Mechanism) and non-BM (non-Balancing Mechanism) market participants. Alternatively please contact us here [box.futureofbalancingservices@n](/cdn-cgi/l/email-protection#98faf7e0b6feedecedeafdf7fefaf9f4f9f6fbf1f6ffebfdeaeef1fbfdebd8f6fdebf7b6fdf6fdeaffe1 "feedback")[es](/cdn-cgi/l/email-protection#7d1f1205531b0809080f18121b1f1c111c131e14131a0e180f0b141e180e3d13180e12531813180f1a04)[o](/cdn-cgi/l/email-protection#f3919c8bdd9586878681969c9591929f929d909a9d94809681859a909680b39d96809cdd969d9681948a "feedback")[.](/cdn-cgi/l/email-protection#82e0edfaace4f7f6f7f0e7ede4e0e3eee3ece1ebece5f1e7f0f4ebe1e7f1c2ece7f1edace7ece7f0e5fb)[energy](/cdn-cgi/l/email-protection#3b595443155d4e4f4e495e545d595a575a555852555c485e494d52585e487b555e4854155e555e495c42 "feedback") | [Name](?order=title&sort=asc "sort by Name") | | --- | | [Slow Reserve proposed service design - December 2024](/document/349036/download) | Document library Rich text Webinars | | | --- | | [Quick Reserve and Slow Reserve webinar recording – 9 March 2023](https://players.brightcove.net/6415851838001/default_default/index.html?videoId=6351773221112) | | [Response and Reserve Webinar Recording- 04 Nov 2021](https://players.brightcove.net/6415851838001/default_default/index.html?videoId=6351772928112) | Documents | [Name](?order=title&sort=asc "sort by Name") | [Published](?order=field_publication_date&sort=asc "sort by Published") | | --- | --- | | [OBP Service Provider - Web Services Specification](/document/350286/download) | 19 Dec 2024 | | [Slow and Quick Reserve - webinar slides - 9 March 23](/document/277551/download) | 16 Mar 2023 | | [Reserve Reform Show & Listen 2 - 26.05.22](/document/260111/download) | 27 May 2022 | | [Reserve Reform Show & Listen 1 - 28.04.2022](/document/249546/download) | 29 Apr 2022 | | [Slow Reserve Service Summary - April 22](/document/249031/download) | 21 Apr 2022 | | [Slow Reserve Feedback Proforma](/document/248901/download) | 14 Apr 2022 | | [Reserve Reform Update - February 2022](/document/244316/download) | 25 Feb 2022 | | [Reserve Product Reform Consultation](/document/187871/download) | 5 Mar 2021 | Latest news #### Upcoming Webinars and drop in sessions Slow Reserve Drop-in 1 – 26 February – 10:30am – 11:30am During the first week of mock auctions for the new co-optimised Slow Reserve service we will be holding a drop-in session for any questions from providers. The Slow Reserve team will be available to cover mock auctions, onboarding and any issues as we move towards go live of the service [Register](https://www.neso.energy/calendar/slow-reserve-drop-1) Slow Reserve Webinar – 4 March – 2:00pm – 3:00pm Join us for our final Slow Reserve webinar prior to go-live of the service. The Slow Reserve team will cover NESO requirement setting, a brief overview of the technical requirements, onboarding and what to expect in the days prior to the first auction. [Register](https://www.neso.energy/calendar/slow-reserve-webinar) Slow Reserve Drop in 2 – 12 March – 10:30am – 11:30am Our second drop-in session for any questions from providers regarding the new Slow Reserve service. The Slow Reserve team will be available to cover mock auctions, onboarding and any issues as we move towards go live of the service [Register](https://www.neso.energy/calendar/slow-reserve-drop-2) 19 May 2023 ESO has come to the decision to delay the delivery of the new Reserve reform products, Slow and Quick Reserve – originally planned for October and November 2023. As a result, we will not be launching our EBR Article 18 consultation to industry as planned at the end of May. This decision has been taken in light of the significant changes that would have been required in our existing, legacy balancing systems and processes, given the complexity of the new service designs. In the midst of a complex and rapidly evolving systems change environment, we believe it is more prudent to re-evaluate these changes to consider if implementation into our legacy systems is still appropriate, as opposed to direct implementation into our Open Balancing Platform (OBP). Postponing the rollout of our new Reserve services grants us the opportunity to re-examine our proposed service designs, evaluate our IT options, and collaborate with you more effectively. This will ensure that the best solutions are delivered and that the necessary updates to our balancing systems are apt for enhancing our operational toolkit and are better aligned with the implementation of our future systems. In the coming weeks we will be looking to understand the extent to which we review the proposed services designs and IT solutions. We will then communicate how and when we intend to engage with you in this process via the Future of Balancing Services distribution list. 20 April 2023 Last month, we held a webinar on 9 March where we updated industry on our delivery plan and provided a refresh of the services (please refer to the Document Library tab for the documentation and recordings). This delivery plan indicated launching our EBR consultation towards the end of April with the dependencies being further exploration of system changes and the quantum of change acceptable to market providers as well as the ENCC. We have also noted the feedback on Crossovers from the market and we are still analysing the most optimal solution for the end consumer. As we are still working through these dependencies and feedback, the EBR consultation will be moved provisionally to the end of May. We intend to update and confirm our delivery plan for Quick Reserve and Slow Reserve in Future of Balancing Services newsletter. Past events ### Slow Reserve drop-in session 12 March 2026 Following the drop-in held on 12 March 2026, we have shared the slides and a recording of the drop-in. [Watch the webinar](https://youtu.be/H9p2S2KYUQc) [Download the slides](https://www.neso.energy/document/378576/download) ### Slow Reserve Webinar 4 March 2026 Following the webinar held on 4 March, we have shared the slides and a recording of the webinar. [Watch the webinar](https://youtu.be/-Mqofozf6h4) [Download the slides](https://www.neso.energy/document/377891/download) ### Slow Reserve drop-in session 26 February 2026 Following the drop-in held on 26 February 2026, we have shared the slides and a recording of the drop-in. [Watch the webinar](https://youtu.be/25dsRx3EVmw) [Download the slides](https://www.neso.energy/document/377886/download) ### Slow Reserve Technical Onboarding Webinar 6 November 2025 Following the webinar held on 6 November 2025, we have shared the slides and a recording of the webinar. [Watch the webinar](https://players.brightcove.net/6415851838001/default_default/index.html?videoId=6384782706112) [Download the slides](https://www.neso.energy/document/371506/download) ### Slow Reserve Webinar 11 February 2025 Following the webinar held on 11 February 2025, we have shared the slides and a recording of the webinar. [Watch the webinar](https://players.brightcove.net/6415851838001/default_default/index.html?videoId=6368708098112) [Download the slides](https://www.neso.energy/document/355196/download) ### Reserve Reform Update Webinar 19 December 2023 Following the webinar held on 19 December 2023, we have shared the slides and a recording of the webinar. [Watch the webinar](https://players.brightcove.net/6415851838001/default_default/index.html?videoId=6351774594112) [Download the slides](/document/299861/download) [Download the Q&A](/document/299866/download) ## Slow Reserve Consultations Consultation Closed: 9th October 2025 On 9th October 2025, Ofgem set out its decision to approve the proposed Service Terms and Procurement Rules for the new Slow Reserve service. As part of these proposed new Slow Reserve terms and conditions, NESO extend its product co-optimisation across the current day ahead auction platform so as to include Slow Reserve alongside Quick Reserve, Dynamic Response, and Balancing Reserve, resulting in a single, simultaneous, co-optimised auction. Ofgem Decision Ofgem Submission Documents Industry Consultation Documents Supporting Documents Ofgem Decision Ofgem Submission Documents Industry Consultation Documents Supporting Documents | | | --- | | [Ofgem Decision - 9th October 2025](https://www.ofgem.gov.uk/transparency-document/amendments-terms-and-conditions-relating-balancing-new-slow-reserve-service) | Rich text On 1st August, NESO submitted to Ofgem the following documentation relating to proposed Slow Reserve Service Terms and Procurement Rules for it's consideration and expected decision on 1st October. Having consulted with industry, NESO also publishes its responses to feedback below. | [Name](?order=title&sort=asc "sort by Name") | | --- | | [Slow Reserve - EBR Article 18 industry feedback responses](/document/366111/download) | | [Slow Reserve Service and Procurement Design](/document/366106/download) | | [Slow Reserve Procurement Rules - Clean](/document/366101/download) | | [Slow Reserve Procurement Rules - Compare](/document/366096/download) | | [Slow Reserve Service Terms - Clean](/document/366091/download) | | [Slow Reserve Service Terms - Compare](/document/366086/download) | | [Slow Reserve Cover Letter and Mapping Document for Ofgem](/document/366081/download) | ## Industry Consultation Documents | [Name](?order=title&sort=asc "sort by Name") | | --- | | [Slow Reserve A18 Proforma](/document/360621/download) | | [Letter to Industry and Mapping Document](/document/360616/download) | | [Proposed Slow Reserve Service Terms](/document/360636/download) | | [Slow Reserve Pricing Proposal](/document/360626/download) | | [Proposed Slow Reserve Procurement Rules](/document/360631/download) | | [Name](?order=title&sort=asc "sort by Name") | | --- | | [Slow Reserve Transition Plan](/document/360661/download) | | [Proposed Slow Reserve Service Design](/document/360666/download) | | [Slow Reserve Crossover Guidance](/document/360656/download) | | [Proposed Form C](/document/360646/download) | | [Proposed Slow Reserve Market Design](/document/360641/download) | | [Proposed Form B](/document/360651/download) |  [## Further enquiries](/cdn-cgi/l/email-protection#c0a2afb8eea6b5b4b5b2a5afa6a2a1aca1aea3a9aea7b3a5b2b6a9a3a5b380aea5b3afeea5aea5b2a7b9) Get in touch with the right team within Balancing Services, who are on hand to answer any questions you may have. [Contact the Future of Balancing Services Team](/cdn-cgi/l/email-protection#4e2c213660283b3a3b3c2b21282c2f222f202d2720293d2b3c38272d2b3d0e202b3d21602b202b3c2937) ## Footer * [About NESO](/about-neso) + [Who we are](/about/our-people) + [Operational information](/about/operational-information) + [Careers](/careers) + [Applications, portals and APIs](/applications-portals-and-apis) * [Contact us](/contact-us) + [How to report a power cut](/energy-outages) + [Help centre](https://portal.nationalenergyso.com/nesoHelpCentre/s/) + [Media centre](/news-and-events/media-centre) * [Corporate information](/corporate-information) + [Suppliers](/suppliers) + [Freedom of Information and Environmental Information Regulations](/corporate-information/freedom-information-and-environmental-information-regulations) + [Modern Slavery Statement](/corporate-information/modern-slavery-statement) + [Public Sector Equality Duty (PSED)](/corporate-information/public-sector-equality-duty-psed) ## Site * [Accessibility](/accessibility) * [Privacy notice](/privacy-notice) * [Cookie policy](/cookie-policy) * [Terms and Conditions](/terms-and-conditions) * [Security](/security) * [Responsible Disclosure](/responsible-disclosure) ## Social * [Twitter](https://x.com/NESO_energy) * [LinkedIn](https://www.linkedin.com/company/neso-energy) * [YouTube](https://www.youtube.com/%40NESO_energy)  logo--facebook