A flexibility provider is a user who provides flexibility services by making temporary changes to the way they consume, generate, or store electricity when requested by the electricity networks. This allows the network operators to optimise their capacity, whilst remunerating users for the services provider.
ENA’s Open Networks programme was instrumental in informing the transition to Distribution System Operation (DSO) and establishing the UK as the world leader in the development of local flexibility markets. Since its establishment in 2017, Open Networks developed the UK’s local flexibility market from the ground up, starting from developing a UK-wide business case and market principles to the formulation of procedures and technical specifications. Driven by the government’s Smart Systems and Flexibility Plan and supported by Ofgem, we worked to make the energy flexibility market easier to take part in, more coordinated, and more transparent.
This web page is intended to be an initial source of information to new and existing flexibility service providers to aid them in participating in the local flexibility market. The figure below illustrates a high-level local flexibility market’s delivery journey noting actions undertaken by the DSO and the Flexibility Service Providers (FSPs).
Key outputs from the Open Networks programme associated with individual steps are signposted below, and FSPs are encouraged to refer to individual DSOs websites for further information regarding their respective tenders.
Click here for an accessible version of the graph
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Planning and Forecasting
Network forecasting across a range of scenarios
In the pre-tender stage, the key activities are forecasting and network needs identification. All DNOs/DSOs generate and publish demand and generation forecasts in their Distribution Future Energy/Electricity Scenario (DFES) documents. From May 2022, DSOs have developed and published their Network Development Plans (NDP) that detail their network’s future needs for the next 10 years.
The Network Development Plans have been created to present the 'best view' of planned asset base and flexible network developments over the five to ten-year period. DNOs/DSOs produce NDPs which include their plans for reinforcements, the use of flexibility services, and network capacity reporting. Different network reports, have different purposes and therefore have a range of timeframes and content. DFES documents provide long term forecasts of future energy pathways with a view up to 2050 in order to capture the envelope of uncertainties while Long Term Development Statements (LTDS) provide information on our existing network and availability of capacity in the next 5 years. NDPs fill the gap in information on our network development in the medium-term between 5-10 years.
Links to individual Network companies’ DFES
Distribution Network
Link
Electricity North West
National Grid Electricity Distribution
Northern Powergrid
SP Energy Networks
Scottish and Southern Energy Networks
UK Power Networks
Links to individual Network companies’ NDP
Distribution Network
Link
Electricity North West
https://www.enwl.co.uk/get-connected/network-information/network-development-plan/
National Grid Electricity Distribution
National Grid Electricity Distribution - Network Development Plan
Northern Powergrid
https://www.northernpowergrid.com/network-data [northernpowergrid.com]
SP Energy Networks
Network Development Plan - SP Energy Networks [spenergynetworks.co.uk]
Scottish and Southern Energy Networks
UK Power Networks
Long Term Development Statement and Network Development Plan Landing Page — UK Power Networks
Relevant documents and links
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Evaluation of Network Need
A key activity undertaken by each DSO is the evaluation of intervention options for mitigating a network need. The CEM tool is built to enable DSOs to make investment decisions when comparing flexibility products to traditional network interventions.
Since the launch of the first version CEM in 2020, the tool has evolved through structured engagement with users of the tool and third parties. A third version of the CEM tool has been released in 2024.
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Pre-qualification of Assets
To access the market, flexibility providers need to register their assets and understand which markets their assets can participate in. Flexibility providers are asked to provide basic information about their asset and organisation, which will then undergo a review to determine their eligibility to participate in the flexibility market. In 2024, all network operators use a set of standard technical and commercial criteria for an asset to pre-qualify.
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Tender Launch and Response
System operators publish flexibility opportunities, and flexibility providers can identify opportunities that they can respond to. Constraints on networks are confined to specific geographical locations; DSOs define these locations as Constraint Management Zones (CMZ). The platforms can provide a map of CMZs locations and a postcode finder to allow potential flexibility providers to confirm their site is within the limits of the zone. These platforms also facilitate prequalification of assets.
The platforms presently in use (as of 2025) are
- Piclo Flex – Used by SPEN and NPg
- Electron Connect – Used by SSE and ENW
- Local Flex – Used by UKPN
- Market Gateway & Piclo Flex – Used by NGED
Once qualified, providers will be in a position to submit a bid or offer to deliver flexibility for the opportunities that constitute a suite of standard products. Flexibility providers can review all technical requirements of the available market opportunities published by system operators. A flexibility provider submits a bid by providing the required dynamic market information. Once a system operator has reviewed bids, the service provider will be notified of their bid being accepted. This process can be facilitated by a platform provider.
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Flexibility Products
When considering how best to solve network congestion using flexibility, different flexibility products can be used depending on the specific network scenario. These flexibility products can primarily be differentiated by their intended utilisation conditions and notice period.
In 2018, ENA launched four defined products which have been used to facilitate a range of new and interesting markets, increasing market fluidity extensively. The products were then reassessed to investigate differences. A consensus was achieved across all GB DSOs to launch 5 new/rebranded flexibility products for utilising DSO flexibility services beyond 2023. These new products superseded the previous 2018 released standard products. The DSOs would ensure that at least 80% of tendered flexibility across DSOs is tendered through common products by the summer of 2024.
- Flexibility Products: Active Power Service definition and implementation plan Publication (2020) – Superseded
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Contracting
Having identified the need for flexibility services, the system operator will define the specific requirements, review the received bids and select those most optimal. The DSO will then contract the required flexibility service with the selected provider. All DSOs use a standard agreement to contract flexibility services. The contract has evolved over the years, with all DSOs using Ver 3.0. NESO uses Ver 2.0 and plans to use Ver 3.0 following a formal consultation.
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Dispatch
When the service is required, the flexibility provider is notified to dispatch their asset. This notification could be through automated instruction, platform notification, or by phone. The service provider then dispatches their asset and provides confirmation and real-time monitoring of the assets to the system operator. There is a consensus that the communication of dispatch requirements is best handled at scale via Application Programming Interfaces (APIs). as this will enable the use of automated systems to process dispatch requirements work in underway to develop a standard dispatch API.
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Market Coordination (revenue stacking and primacy)
Stackability
Primacy
Summary
Stackability rules tell a FSP whether they are allowed to offer two services for the next, say, 1-month period, or whether they need to choose which service to offer.
Concerns whether two services can be offered by an FSP in a single delivery window.
Primacy rules apply in real- or near-real time, and define how the system operators are allowed to dispatch a service.
Concerns which system operator can dispatch a service in the event that two services conflict
Timing
Applies at the procurement or pre-procurement (i.e. eligibility) stage
Applies at the operational dispatch stage (i.e. within-day or day-ahead)
Who the rule applies to
Applies to the FSP looking to offer multiple services. Not affected by the actions of other FSPs.
Applies to the system operator (or other 3rd party) looking to dispatch the flexibility service. May not only consider a single FSP, but also the interaction between different FSPs.
Revenue stacking is a key area of interest for flexibility service providers, and we invite you to review our Revenue Stacking Explainer and FAQ’s (2025) for detailed information.
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Baselining (measurement of services delivered)
Baselining is the ‘established level of Distributed Energy Resources (DER ) base load from which a delta is measured to calculate level of service delivered’. This is the measurement on the basis of which the FSP is paid for the dispatched service.
All DSO flexibility products are technology-agnostic, meaning that they are open for all technologies to participate and do not include explicit requirements (or) favouring certain technologies. It is important to understand, however, that certain technologies have a better match with certain products than others.
A tool is available to help flexibility providers follow a clear, common and more accurate approach for measuring how much flexibility they have delivered to Britain’s distribution network operators (DNOs). The baselining verification tool will be used by flexibility providers to explore and determine their baseline calculations for participating in flexibility markets. The tool is available online (to be discontinued end of 2025), along with an accompanying user guide which provides further information on the purpose of the tool and how to use it.
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Settlement
Settlement is the payment for the supply of flexibility services from a service provider.
Individual service design can vary, dependent on the need of a System or Network Operator, but in general there can be two payment components:
- Availability payments
- Utilisation payments
Signage used in calculations for different asset types
Response Type
Direction
Baseline Value
Meter Readings
Dispatched Capacity
Demand
Turn Down
Negative
Negative
Positive
Demand
Turn Up
Negative
Negative
Negative
Generation
Turn Down
Positive
Positive
Negative
Generation
Turn Up
Positive
Positive
Positive
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Information Sharing
Publishing statistics and statements reporting process about the aggregation and publication of market data fed into market to inform future opportunities and bids.
GB flexibility Figures
Since 2018, ENA’s Open Networks has tracked the growth of the local flexibility by collating the total tendered flexibility (the total volume of flexibility the networks are looking to procure) and the total contracted flexibility (the volume of flexibility that was available at the right time and location to alleviate network constraints). These are tracked every 12 months. Reporting was moved to align with the DNOs flexibility statement submissions in 2021 (a regulatory submission to Ofgem under the licence condition (SLC31E)).
Local flexibility services are playing a bigger and more important role in providing clean, reliable energy to Britain’s homes, businesses, and communities and help us reach net zero. In past 3 years of reporting more than 70% of flexibility came from renewable energy sources.