BW ESS Secures Financing for 400 MW Hams Hall Battery in the West Midlands
BW ESS announced on 22 October 2026 that it had secured debt financing for the Hams Hall battery in the West Midlands. At 400 MW and 1,424 MWh when fully built, it is one of the largest battery projects in Britain.
What was announced
The project sits next to National Grid's Hams Hall substation. Phase 1 will provide 350 MW and 1,243 MWh, and Phase 2 will take the site to 400 MW and 1,424 MWh. OCBC, Rabobank and Societe Generale each provide an equal share of the debt, with Rabobank also acting as facility agent. More than 30 lenders took part in the process.
Phase 1 revenues are backed by a 10-year floor and optimisation agreement with EDF. The site is part of the 2.6 GWh Ardenham portfolio, which BW ESS co-owns with AIP Management. We could not find a stated date for commercial operation.
Claims we are treating with care
The company says the site could support about 1.3 million homes for up to 3.5 hours. That is a vendor illustration of stored energy, not a forecast of what households will experience. The announcement also describes the project as the largest battery in Europe by MWh at completion, a claim attributed to OCBC. We have not checked it independently.
The grid queue context
Grid connection is the scarce resource for large batteries in Britain. In September 2026 Ofgem proposed a financial commitment for battery projects waiting in the connections queue. It said about 90 GW of battery capacity is operational or in the reformed queue, against a projected need of around 29 GW by 2035. A project that has reached financing is a sign that it has moved from the queue to construction.
Ofgem expected to publish its final decision on that commitment later in 2026, and we have not seen a final decision at the time of writing.
What it means for homes
Large batteries and home batteries both move electricity from cheap, plentiful periods to expensive ones, but they do not compete for the same customers. This announcement does not change what a home battery costs or saves. If you are weighing one, our explainer on how a home battery saves money is a better place to start, and the home battery calculator lets you test your own numbers.
Sources
- Blackridge Research: BW ESS secures international debt financing for 400 MW / 1,424 MWh Hams Hall battery storage project
- Energy Global: BW ESS secures international financing for 400 MW/1,424 MWh Hams Hall BESS
- Ofgem: Ofgem moves to free up grid capacity by tackling excess battery projects
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