EDF and BW ESS, a global developer, owner, and operator of energy storage systems, have entered into a partnership for the initial phase of the Hams Hall Battery Energy Storage System (BESS) located in North Warwickshire, United Kingdom. This project represents a 350 MW/1,243 MWh grid-scale battery installation and is the longest-duration battery project ever contracted by EDF to date (EDF press release, 28/04/2026).
Upon completion, phase one of Hams Hall is expected to meet the electricity demand of around 1.3 million homes during peak times, with a discharge duration of up to 3.5 hours. EDF will oversee the project through a ten-year floor agreement and will rely on its PowerShift platform to optimise performance. The project is expected to be commissioned in the fourth quarter of 2026. A second development phase is planned, which would add 50 MW, increasing the total project capacity to 400 MW / 1,424 MWh.
Hams Hall is part of BW ESS’s UK portfolio and is jointly owned by BW ESS and AIP Management, an investor specialising in energy and decarbonisation.
According to the company, the project contributes to EDF’s expanding battery storage portfolio, supporting the growing importance of grid-scale batteries in balancing the electricity system as wind and solar capacity continue to expand across the UK.