BW ESS’s Hams Hall Battery Storage Project Enters Commercial Operation in the UK, Delivering 1,243 MWh of Storage Capacity

London, November 2, 2026 – Global energy storage developer and operator BW ESS has announced the start of commercial operations for the first phase of its Hams Hall Battery Energy Storage System (BESS) in the West Midlands, United Kingdom.

The first phase delivers 350 MW / 1,243 MWh of battery storage capacity, making Hams Hall Europe's largest operational battery energy storage project by installed energy capacity (MWh).

Located adjacent to National Grid’s Hams Hall substation, the project is designed to support electricity grid balancing by storing excess electricity and releasing it when demand increases. It will also facilitate the integration of renewable energy into the UK power system, helping strengthen grid resilience and energy security.

The project reached commercial operation just 20 days after energisation. BW ESS worked closely with project partners, including Sungrow, Energy-IO, National Grid and the National Energy System Operator (NESO), throughout the commissioning and testing process.

Following completion of its second phase, Hams Hall is expected to expand to a total capacity of 400 MW / 1,424 MWh. At full capacity, the project will be capable of supporting the electricity needs of approximately 1.3 million homes for up to 3.5 hours.

“The start of commercial operations at Hams Hall is a landmark moment for BW ESS and a significant addition to Europe’s energy infrastructure,” said Erik Strømsø, CEO and Co-Founder of BW ESS.

The project's long-term revenues are supported by a 10-year floor and optimisation agreement with EDF, providing a framework for revenue stability and battery asset optimisation.

Hams Hall forms part of BW ESS’s 2.6 GWh Ardenham portfolio, which is co-owned with energy and decarbonisation investor AIP Management.

The project further strengthens BW ESS’s presence in the UK energy storage market. Alongside the 331 MWh Bramley BESS in Hampshire, the company also has 857 MWh of battery storage capacity under construction at Berkswell, with a broader development pipeline spanning multiple gigawatt-hours.

As renewable energy deployment continues to expand across the UK, large-scale battery storage projects such as Hams Hall are expected to play an increasingly important role in balancing electricity supply and demand, improving grid flexibility and supporting the country's energy transition.