Clean Flexibility Roadmap: A Step Towards a Sustainable Energy System

UK battery capacity hits 7.5GW as flexibility roadmap enters delivery phase

Britain’s electricity system added 2.3GW of battery storage in 2025, bringing total grid-scale capacity to 7.5GW by year end. The figure marks the strongest annual deployment on record and keeps the UK ahead of European neighbours in installed battery capacity. Meanwhile, industry and commercial sites delivered 170MW of new flexibility through the Balancing Mechanism and Demand Flexibility Service, meeting the first annual target set under the Clean Flexibility Roadmap.

The Department for Energy Security and Net Zero, Ofgem, and National Energy System Operator published their first annual progress report in July 2026. It signals a shift from target setting to delivery monitoring. New performance indicators now track consumer-led flexibility, which has received fresh commitments from all three organisations. The report also confirms that Ofgem is minded to support 7.6GW of long-duration energy storage across 16 projects, representing 137GWh of capacity.

These developments follow the roadmap’s launch on 23 July 2025, when the three bodies published the first unified strategy to unlock flexibility across Great Britain’s electricity system. The document sets out plans to deliver between 10GW and 12GW of flexibility by 2030, supporting clean power ambitions and the 2050 net zero commitment.

How the roadmap defines and organises flexibility

Clean flexibility means shifting when or where electricity is produced or used to reduce costs and carbon emissions. It covers everything from grid-scale batteries and interconnectors to consumer devices such as electric vehicle chargers, heat pumps, and home battery systems. The roadmap groups these technologies and approaches into four pillars.

Short-duration flexibility operates on timescales from seconds to several hours. It includes consumer-led flexibility, grid-scale batteries, and interconnectors with neighbouring countries. Long-duration flexibility spans multi-hour to seasonal timescales. This category covers large-scale storage technologies and dispatchable low-carbon generation.

Cross-cutting enablers include market design, network planning, digitalisation, planning reform, and supply chain development. The fourth pillar addresses governance and delivery, setting out clear responsibilities, milestone tracking, and accountability mechanisms. This structure ensures different flexibility types receive coordinated policy support rather than competing for attention.

Battery deployment leads European market

The 7.5GW of grid-scale battery capacity installed by end-2025 places Britain at the forefront of European energy storage deployment. Battery storage responds to price signals and grid conditions within milliseconds, providing frequency response and helping balance supply and demand. As a result, these assets reduce the need for fossil fuel peaking plants and lower overall system costs.

The 2.3GW energised during 2025 represents a significant acceleration in deployment rates. Developers have responded to improved market access and clearer revenue signals introduced through earlier reforms. Batteries can now participate in multiple markets, stacking revenues from services such as frequency response, capacity market payments, and wholesale trading.

However, grid connection timescales remain a constraint. Many projects still face lengthy waits for network upgrades, particularly in areas with high renewable generation. Ofgem’s queue management reforms, announced in February 2026, aim to prioritise projects that can deliver quickly and provide genuine system value.

Industrial and commercial sites deliver first flexibility target

The 170MW of new industrial and commercial flexibility exceeded the first annual milestone. Businesses achieved this by offering demand reduction or generation during peak periods through the Balancing Mechanism and Demand Flexibility Service. Manufacturing sites, cold storage facilities, and water treatment plants have shown particular interest in these services.

Companies receive payments for adjusting electricity use at short notice, creating a new revenue stream while helping National Energy System Operator balance the grid. For example, a food processing plant might delay refrigeration cycles by an hour during peak demand, or a factory could shift production to overnight periods when electricity prices fall.

This commercial flexibility differs from residential demand response in both scale and sophistication. Industrial sites typically have dedicated energy management teams and existing control systems. Consequently, they can respond to price signals more quickly and reliably than domestic consumers. Nevertheless, unlocking wider commercial participation requires simpler contracts and better integration with existing business processes.

Long-duration storage receives regulatory backing

Ofgem’s provisional support for 7.6GW of long-duration energy storage addresses a critical gap in the flexibility market. These projects provide storage lasting several hours or days, compared to batteries that typically discharge within two hours. The 137GWh of total capacity would allow the system to store surplus renewable generation and release it during extended periods of low wind or solar output.

The 16 projects receiving regulatory support include pumped hydro facilities, compressed air energy storage, and liquid air energy storage. Each technology offers different characteristics in terms of response time, duration, and geographical requirements. Pumped hydro needs specific topography, while liquid air systems can be built on industrial sites.

Ofgem’s support mechanism provides revenue certainty for developers, addressing the key barrier to investment in long-duration storage. Without this intervention, projects struggle to secure financing because revenue depends on unpredictable price volatility. The regulator’s minded-to position indicates strong approval, though final decisions await completion of the evaluation process.

Consumer flexibility reforms enable household participation

Code modification P483 removes a significant technical barrier to domestic and small business flexibility. The change allows aggregators to trade flexibility using asset-level metering before Marketwide Half-Hourly Settlement arrives. Previously, aggregators needed whole-premise half-hourly data, which excluded most households and small firms.

Asset-level metering measures individual devices such as electric vehicle chargers, heat pumps, or batteries rather than total property consumption. Therefore, aggregators can now pay households for adjusting specific appliances while leaving other electricity use unchanged. This precision matters because it means families don’t need to shift their entire consumption pattern to participate.

The reform accelerates the timeline for consumer flexibility by several years. Marketwide Half-Hourly Settlement won’t arrive until 2030 at the latest, but P483 allows households to start earning from flexibility immediately. Smart appliances, home batteries, and electric vehicles can now generate revenue through aggregator platforms that pool many small assets into grid-scale resources.

Time-of-use tariffs also continue to expand. Electric vehicle drivers can access discounts on public charging during off-peak periods, while home energy tariffs increasingly offer cheaper overnight rates. These pricing structures encourage consumers to shift demand naturally without complex technology. For instance, households might charge vehicles overnight or run dishwashers during periods of low wholesale prices.

Network connection reforms tackle data centre queue

Ofgem’s Curate, Plan, Connect reforms respond to a surge in speculative connection applications, particularly from data centres. The February 2026 announcement introduces stricter criteria for new connections and prioritises projects of strategic national importance. This addresses concerns that speculative applications block network capacity while genuine projects face delays.

The government is also developing alternative connection agreements for large demand customers. These contracts will include voluntary flexibility services and operational control measures, allowing network operators to manage local constraints without expensive infrastructure upgrades. An update on this work is expected in autumn 2026.

Distribution network operators must submit build and flex strategies as part of RIIO-ED3 business plans in December 2026. These strategies will show how companies plan to use flexibility services before resorting to traditional network reinforcement. Consequently, areas with high demand growth may see faster connections if flexibility can defer or avoid upgrades.

Progress measured through new performance indicators

The July 2026 annual update introduces key performance indicators to track delivery against roadmap commitments. This marks a transition from aspirational targets to measurable outcomes. Consumer-led flexibility receives particular attention through dedicated metrics covering participation rates, capacity enrolled, and actual demand reduction achieved.

Other indicators track market access barriers, technology skip rates, and network constraint costs. Skip rates measure how often flexibility assets receive dispatch instructions but can’t respond due to technical or commercial barriers. National Energy System Operator aims to reduce these rates significantly by March 2026 through improved market rules and better coordination with network operators.

The performance framework creates accountability across all three organisations. Department for Energy Security and Net Zero monitors policy delivery, Ofgem tracks regulatory reforms, and National Energy System Operator reports operational outcomes. Regular industry feedback loops ensure the roadmap adapts to emerging issues and technological developments.

Market reforms create sharper price signals

The Significant Code Review of Distribution Use of System charges will introduce granular locational and temporal pricing signals. This reform encourages customers to reduce demand during local network peaks or shift consumption to periods when local generation exceeds demand. Current charging structures don’t reflect these variations, so customers lack incentives to help manage local constraints.

More precise pricing will particularly benefit businesses with flexible demand. For example, a warehouse might install batteries to avoid high charges during local peak periods, or a factory could adjust production schedules to use surplus local renewable generation. These changes reduce network costs and defer infrastructure investment.

Voltage management could see wider deployment following an autumn 2025 Ofgem consultation. This technique allows network operators to slightly reduce voltage during peak periods, cutting overall demand without affecting customer equipment. Trials have shown that customers rarely notice small voltage reductions, but the aggregate demand reduction can avoid expensive network upgrades.

Five critical delivery milestones for flexibility

Grid-scale battery capacity reached 7.5GW by end-2025, with 2.3GW added during the year. This maintains Britain’s lead in European battery deployment. Industrial and commercial sites delivered 170MW of new flexibility capacity through the Balancing Mechanism and Demand Flexibility Service, meeting the first annual target.

Ofgem expressed provisional support for 7.6GW of long-duration energy storage across 16 projects, totalling 137GWh of capacity. Code modification P483 now allows aggregators to trade domestic and small business flexibility using asset-level metering before full half-hourly settlement arrives. The July 2026 progress report introduced new key performance indicators focusing on consumer-led flexibility and delivery monitoring.

What businesses should consider about flexibility opportunities

Companies with significant electricity demand should review whether their operations can participate in flexibility markets. Manufacturing sites, cold storage facilities, and water treatment plants often have processes that can shift timing without affecting output quality. These operational adjustments create new revenue streams while reducing exposure to peak electricity prices.

Businesses planning major investments in electric vehicle fleets or heat pumps should consider how smart controls could unlock flexibility value. Managed charging or heating schedules can cut energy costs substantially while earning payments for providing grid services. However, these benefits depend on having the right metering and control infrastructure in place from the start.

Property developers and industrial site operators need to engage early with network connection processes. The Curate, Plan, Connect reforms will change how applications are assessed and prioritised. Projects with genuine flexibility or strategic national importance will receive preferential treatment, while speculative applications face tougher scrutiny.

Supply chain businesses should note the £1bn Great British Energy Clean Energy Supply Chain Fund launched in 2025. The National Wealth Fund is also investing in low-carbon flexibility technologies. These funding sources create opportunities for UK manufacturers and service providers in the flexibility sector. Moreover, companies participating in public sector supply chains may face growing expectations around flexibility and carbon reduction under procurement rules such as PPN 06/21.

Retailers and aggregators should prepare for Marketwide Half-Hourly Settlement implementation by 2030. This will enable more sophisticated time-of-use tariffs and real-time retail products. Companies that develop customer propositions and operational capabilities early will have significant competitive advantages. In addition, our ESG compliance support helps businesses understand reporting requirements around carbon reduction and sustainability commitments.

The government estimates consumer flexibility could deliver £70bn in savings by 2050 through off-peak electricity use. These savings will flow to households and businesses that adopt smart technologies and adjust consumption patterns. Companies advising customers on energy efficiency should incorporate flexibility into their recommendations, as it often provides faster payback than traditional efficiency measures.

Where to find official guidance and updates

The Department for Energy Security and Net Zero publishes the Clean Flexibility Roadmap and annual progress reports on gov.uk. These documents provide the most authoritative source for policy commitments, delivery milestones, and strategic direction. Ofgem maintains detailed information about electricity market reforms and flexibility services on its website, including consultation documents and decision letters.

National Energy System Operator publishes technical guidance on participating in flexibility markets through its Balancing Mechanism and ancillary services pages. These resources explain how businesses and aggregators can register assets and access different revenue streams. The operator also publishes regular system operability reports showing how flexibility contributes to managing the electricity system.

Businesses seeking practical support with carbon reduction and sustainability compliance can access training through SBS Academy, which covers topics including energy management, Scope 3 emissions, and supply chain sustainability. Our net zero programme provides specific guidance on carbon reporting requirements and PPN 06/21 compliance for public sector suppliers.