Europe's largest battery storage system goes live at Hams Hall
BW ESS says its 1,243MWh battery in North Warwickshire is now Europe's largest operational battery by energy storage capacity.
In Brief
- BW ESS has confirmed that the first phase of its Hams Hall battery energy storage system in North Warwickshire has entered commercial operation.
- The facility provides 350MW of power capacity and 1,243MWh of energy storage, making it Europe's largest operational battery by stored energy capacity.
- Connected to National Grid's 400kV transmission network, the battery can discharge at its rated power for approximately 3.5 hours.
- BW ESS says the project reached commercial operation 20 days after energisation, following commissioning and testing involving Sungrow, Energy-IO, National Grid and NESO.
- A planned second phase will increase capacity to 400MW/1,424MWh, while EDF has a ten-year agreement to optimise the battery's operation.
In Review
BW ESS has brought the first phase of its Hams Hall battery energy storage system into commercial operation, making it Europe's largest operational battery by energy storage capacity.
The facility, located in North Warwickshire near Birmingham, provides 350MW of power capacity and can store 1,243MWh of electricity, enough to discharge at full power for approximately three-and-a-half hours.
That will be key to helping balance the grid, with the battery set to help manage fluctuations in electricity supply and demand. It has the capability to absorb electricity when generation is plentiful and release it when demand increases or renewable output falls.
That’s the exact job that it’ll be performing too – with it connected to National Grid’s 400kV transmission network, with the electrical infrastructure including two 220MVA supergrid transformers.
It comes at an important time too. So far, the UK has spent more than £1.5 billion in 2026 on curtailing renewable energy and turning up more expensive gas power plants. Energy storage has long been lauded as a solution to these spiralling costs – and Hams Hill will now play an important role in balancing the grid.
EDF will optimise Hams Hall's operation under a ten-year floor and optimisation agreement announced in April 2026.
Using its PowerShift platform, EDF will manage when the battery charges and discharges, allowing it to respond to electricity market conditions and provide flexibility to the network.
But while it will already be playing an active role in balancing the grid, Hams Hall isn’t going to be meeting its full potential just yet. A second phase will add another 50MW of power and 181MWh of storage, bringing the installation to 400MW/1,424MWh. It’s not yet clear when that extra capacity will come online, however.
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