Long-duration electricity storage in GB: Ofgem's Window 1

On 26 June 2026, Ofgem published its consultation on Long-duration electricity storage Window 1: Minded-to decisions, marking a significant milestone for the UK's energy storage market. The regulator has provisionally selected 16 LDES projects under Great Britain’s first cap-and-floor support scheme, representing 7.6GW of storage capacity. While the announcement is a positive step for the sector, questions remain about how effectively the cap-and-floor mechanism will unlock investment in long-duration electricity storage and achieve ambitious delivery targets by 2030.