UK’s largest battery storage system powers up

August 23, 2025

The UK has officially launched its largest battery energy storage system (BESS), located in Thurrock, Essex, now live and supplying power to London and the South East. Developed by Statera Energy, the Thurrock Storage project boasts a capacity of 300MW/600MWh, capable of delivering electricity to up to 680,000 homes for over two hours during peak demand.

Thurrock storage connects to national grid

The project has been successfully integrated into the National Grid's transmission network via the Tilbury substation, which has undergone a major upgrade with advanced protection and control systems to handle the increased load from the battery site.

Tom Vernon, CEO and founder of Statera Energy, highlighted the system’s role in grid reliability:

“As renewable energy sources like wind and solar fluctuate, having large-scale battery storage is vital to balancing the grid. Thurrock Storage ensures clean energy is stored efficiently and deployed exactly when needed.”

National Grid’s Coal Legacy Becomes a Green Future

The Tilbury substation, once used to power coal plants, now supports Britain’s green energy shift. John Twomey, Director of Customer and Network Development at National Grid Electricity Transmission (NGET), stated:

“Connecting the UK’s biggest battery is a milestone for our clean energy future. Facilities like Thurrock are crucial to achieving a stable and sustainable electricity system.”

Technical capabilities and energy flexibility

Thurrock Storage sits adjacent to Thurrock Flexible Generation, a 450MW gas-fired backup plant designed to support the grid when renewable energy output drops. Together, these facilities can reach full output within 10 minutes, providing rapid-response support to stabilize electricity supply during shortfalls.

Massive investment in energy infrastructure

Statera Energy secured £251 million in 2024 (on top of £144 million in 2023) to finance this flagship energy project. The company currently has over 2.1GW of operational or under-construction capacity in the UK, with a future pipeline exceeding 16GW and plans to invest up to £7 billion by 2030.

Scotland’s auchteraw BESS also goes live

In related news, UK energy firm Field commissioned its largest battery site to date — the Auchteraw 50MW/100MWh facility — near Fort Augustus, Scotland. Positioned north of the constrained B4 transmission boundary, this site can supply power to 150,000 homes for two hours and adds significant capacity to Britain’s energy resilience.

Field currently operates four battery storage sites across Great Britain, with a development pipeline of 4.5GWh.