Ofgem published its minded-to position on 26 June 2026 to provide cap and floor investment support schemes to 7.6GW of new long-duration electricity storage (LDES) projects, according to the government's Clean Flexibility Roadmap update1. The 16 projects involved collectively represent 137GWh of new electricity storage capacity1. The announcement delivers on the LDES cap and floor scheme investment policy that government published in October 2024, and will kick start the building of LDES for the first time in over four decades1.
The new storage capacity is mostly made up of pumped storage hydro and lithium-ion batteries, but also includes a compressed air energy storage project and a vanadium redox flow battery1. The government describes the capacity as a significant contribution to the clean and cost-effective integration of home-grown renewable generation into the electricity system1. Ofgem's role in the regulation of the energy market includes setting out the immediate priority steps for adapting its regulatory frameworks for consumer-led flexibility innovation and diversification of flexibility propositions, and supporting the delivery of window 1 LDES Cap and Floor projects through published regulatory instructions and guidance1.
The LDES decisions sit within a wider flexibility programme. The July 2025 Clean Flexibility Roadmap, jointly published by DESNZ, Ofgem and NESO, set out the government's vision for clean flexibility, and the 2026 update shifts focus from intermediate milestones to longer-term outcomes1. Based on NESO scenario modelling, the roadmap states there could be an eight-fold increase in clean flexibility capacity from 2024 to 20501. UK grid-scale battery storage power capacity reached 7.5GW in 2025, with a record new 2.3GW energised in 2025 alone1. By mid-June 2026, Ofgem and Elexon had overseen the migration of more than 11.3 million smart meters to half-hourly settlement, and a third of Britain's electricity metering systems now operate under half-hourly settlement arrangements1.
"On 26 June 2026, Ofgem published its minded to position to provide cap and floor investment support schemes to 7.6GW of new Long Duration Electricity Storage (LDES) projects"
| Item | Figure |
|---|---|
| Supported capacity | 7.6GW |
| Number of projects | 16 |
| Collective storage capacity | 137GWh |
| Date of minded-to position | 26 June 2026 |
Why it matters for households
Long-duration storage is the part of the electricity system that holds power for hours or days rather than minutes, which is what allows supply to be shifted across calm, cloudy or cold periods when wind and solar output is low. The 137GWh of capacity proposed for support is the first new build of this kind in more than four decades1. For a household, the practical link is the extent to which stored electricity can cover periods when home-grown renewable generation is not available, reducing reliance on other sources of supply at those times. The roadmap frames the wider flexibility programme around consumer control, stating that consumers will have greater control over their energy use and that this can unlock savings without disrupting everyday lives1. It also states that consumer-led flexibility can reduce electricity bills for consumers who choose to have their usage flexed, which can be done through automation, while reducing system costs to the benefit of all billpayers1. The government has committed to rapidly assess the feasibility of consumers accessing government support for low carbon technologies doing so using a flexible tariff, with the option for the consumer to opt out1. It has also said it will take primary legislative powers when parliamentary time allows to enable removal of final consumption levies for demand turn up, which it says would support the use of consumer-led flexibility in addressing network constraints and boost the commercial case for bidirectional electric vehicle chargers and domestic batteries1. The Capacity Market and gas storage sit alongside these arrangements in the wider national supply picture.
What happens next
Ofgem will support the delivery of window 1 LDES Cap and Floor projects, including through published regulatory instructions and guidance1. DESNZ, Ofgem and NESO are running a summer 2026 Roadmap Forum in July 2026 to adopt and take forward the new approaches, progress indicators and commitments outlined in the update1. Government expects to introduce secondary legislation in Parliament later in 20261. NESO will publish skip rate figures for clean flexibility behind thermal constraints by Q3 2026, and will connect the CrowdFlex innovation project outputs within a sandbox environment to live and near-real-time data sources by June 20271. Defra plans to consult in summer 2027 on detailed regulatory policy proposals1.