BW ESS has commissioned Phase I of the Hams Hall BESS project with 350 MW/1,243 MWh
The remaining capacity will come online to reach full capacity under Phase II
The company says the project was commissioned ahead of schedule and within budget
BW ESS, the Switzerland-based global energy storage developer, has announced the commissioning of Phase I of its Hams Hall battery energy storage system (BESS) with 350 MW/1,243 MWh of storage capacity.
The company claims this makes it the largest BESS in Europe by storage capacity to have started operations.
Once Phase II is complete, the project will reach its full capacity of 400 MW/1,424 MWh. This will be capable of supporting the electricity needs of around 1.3 million homes for up to 3.5 hours.
Located near National Grid’s Hams Hall substation in North Warwickshire, the project will enable greater integration of renewable energy and balance variable electricity demand. It will also strengthen grid resilience and energy security, it added.
Erik Strømsø, CEO and Co-Founder of BW ESS, said the project was built and commissioned on budget and ahead of schedule. Part of BW Group, BW ESS worked with companies including Sungrow, Energy-IO, National Grid, and NESO for the project.
The facility has a 10-year floor and optimization agreement with EDF, which secures long-term revenues and is backed by financing from OCBC, Rabobank, and Societe Generale. EDF will use its PowerShift platform to optimize the project. In April 2026, when EDF came on board, the company said it was the longest-duration battery contract it had secured to date.
BW ESS says the Hams Hall project is part of its 2.6 GWh Ardenham portfolio, which is co-owned by AIP Management.
SolarPower Europe says Europe added a record 36 GWh of battery storage in 2025, driven by utility-scale projects. It forecasts annual installations to nearly quadruple by 2030 (see Europe’s Battery Storage Capacity Exceeds 100 GWh).