UK's Long-Duration Energy Storage Projects Advance Grid Reliability

The UK has identified 16 long-duration energy storage (LDES) projects under Ofgem's cap-and-floor scheme, with current capacity at 2.8 gigawatts (GW) and projected £24bn in system savings by 2050.

The UK's electricity system (Great Britain only) now requires long-duration energy storage (LDES) to manage renewable energy output peaks and troughs. As of the article's context, the system has 2.8 GW of operational LDES capacity—primarily 4 pumped-hydro assets like Dinorwig power station (1,728 MW), which has operated since the 1980s. The government defines LDES as technologies storing energy for 4 hours to years, with Ofgem using an 8-hour threshold. Current projects include the Uckfield vanadium flow battery site (90 units storing 21 MWh, enough for 3,000 homes one day). These systems eliminate fossil fuel backup for grid stability, directly reducing the need for fossil fuel plants during renewable energy fluctuations. The projected £24bn in cost savings for the UK energy system by 2050 reflects how LDES makes renewable energy reliable at scale, lowering household energy costs and reducing fossil fuel dependency. What to watch: Scaling LDES capacity to meet growing renewable output. Caveats: The 1.2 GW demand spike example (England's football match against DR Congo on 1 July 2026) is hypothetical; current capacity figures reflect Great Britain (excluding Northern Ireland) as of the article's publication context; LDES technologies include pumped hydro, flow batteries, and compressed air.

Source: Carbon Brief