BW ESS starts Hams Hall, Europe's largest battery by capacity at 1,243 MWh
The first phase of the West Midlands project brings 350 MW / 1,243 MWh online, reaching commercial operation 20 days after energisation.

Key points
- Phase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation.
- BW ESS says it is the largest battery in Europe by MWh.
- Commercial operation came 20 days after energisation.
- Phase two will raise the total to 400 MW / 1,424 MWh.
BW ESS has started commercial operations at the first phase of its Hams Hall battery energy storage system in North Warwickshire, England, adding 350 MW / 1,243 MWh to the grid bw-ess.com
BW ESS newsbw-ess.comOpen source ↗
energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗. The company announced the milestone in London on November 2 and says it makes Hams Hall the largest battery in Europe by storage capacity in MWh
energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗
renewableenergymagazine.com
Renewable Energy Magazinerenewableenergymagazine.comOpen source ↗.
Hams Hall battery: phases and numbers
Phase one reached commercial operation just 20 days after energisation and was built "on budget and ahead of schedule", according to chief executive Erik Strømsø energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗. The site connects to the nearby Hams Hall 400 kV National Grid substation
energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗.
| Parameter | Phase 1 | After phase 2 |
|---|---|---|
| Power | 350 MW | 400 MW |
| Storage | 1,243 MWh | 1,424 MWh |
| Duration | about 3.5 h | about 3.5 h |
BW ESS says the full 400 MW / 1,424 MWh system will be able to support around 1.3 million homes for up to 3.5 hours energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗. Sungrow, Energy-IO, National Grid and the system operator NESO worked with the company on commissioning, testing and preparation for operation
energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗.
How the project is financed
Revenue is underpinned by a 10-year floor agreement with EDF, which guarantees a minimum income while the battery trades in the market energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗. In October BW ESS secured debt financing for the full 400 MW / 1,424 MWh project from OCBC, Rabobank and Societe Generale
energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗. Hams Hall joins the 331 MWh Bramley battery in Hampshire in the company's UK portfolio, and it is part of the 2.6 GWh Ardenham portfolio co-owned with AIP Management
energy-pedia.com
Energy-pediaenergy-pedia.comPhase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWhOpen source ↗
renewableenergymagazine.com
Renewable Energy Magazinerenewableenergymagazine.comOpen source ↗.
Long-duration batteries of this size let the grid store surplus wind and solar output and release it during evening peaks, reducing curtailment of renewables.
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Phase one of Hams Hall brings 350 MW / 1,243 MWh into commercial operation; BW ESS says it is the largest battery in Europe by MWh
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