EDF and BW ESS Partner on 350MW Hams Hall Battery Storage Project
- EDF partners with global energy storage developer BW ESS to optimise the first phase of the Hams Hall Battery Energy Storage System (BESS) in North Warwickshire
- The project will provide EDF’s longest battery duration to date, capable of delivering power for up to 3.5 hours
- When operational, Hams Hall Phase One will offer 1,243MWh of storage capacity, supporting the electricity needs of around 1.3 million homes during peak demand
EDF and BW ESS, the global energy storage developer, owner and operator, have partnered on the first phase of the Hams Hall Battery Energy Storage System (BESS) in North Warwickshire, a 350MW / 1,243MWh grid-scale battery project and the longest duration battery EDF has contracted to date. The project will help support a more flexible and resilient UK electricity system as renewable generation continues to grow.
Under the terms of a 10-year floor agreement, EDF will optimise the project using its PowerShift platform, enabling the battery to deliver flexibility to the electricity system by balancing supply and demand, supporting grid stability and helping integrate increasing volumes of renewable generation.
The project will initially deliver 350MW of capacity, with a second phase adding 50MW to bring the total site capacity to 400MW / 1,424 MWh. Currently under construction on the northeastern fringe of Birmingham, the project is expected to reach commercial operation in Q4 2026.
Hams Hall forms a key part of BW ESS’s UK portfolio and is co-owned with leading energy and decarbonisation investor AIP Management. Upon completion it will become BW ESS’s largest capacity project globally; four times larger than Bramley BESS (100 MW / 331 MWh), which was the UK’s largest at the time of its inauguration in February 2025.
Once operational, the batteries will be capable of supporting the electricity needs of around 1.3 million homes for up to 3.5 hours, providing a significant boost to UK energy security and system flexibility. The site benefits from proximity to major electricity load centres and is connected at the nearby Hams Hall 400kV National Grid substation, reducing congestion risks while maximising access to arbitrage and balancing services.
Stuart Fenner, Wholesale Market Services Director at EDF, said: “Hams Hall will be the longest duration battery EDF has contracted to date. By optimising it through our PowerShift platform, we can unlock the flexibility needed to support more renewable power and help deliver EDF’s purpose of electrifying Britain.”
Kilian Leykam, Executive Director, Revenue, BW ESS, added: “We’re very pleased to welcome EDF as our optimisation partner on the Hams Hall project. This collaboration enables a revenue structure designed to maximize the commercial potential of this strategically important UK asset. By combining BW ESS’s experience in developing and operating utility-scale battery storage projects with EDF’s optimisation expertise, we will ensure that Hams Hall delivers exceptional value while fulfilling its role as a key flexibility asset in the UK electricity system.”
The project forms part of EDF’s growing battery storage portfolio, supporting the increasing role of grid-scale batteries in balancing the electricity system as wind and solar generation continue to expand across the UK.
About EDF
EDF is driving the transition towards An Electric Britain – a secure, affordable, low-carbon future for everyone. As Britain’s biggest generator of zero carbon electricity, we are investing more than £100 million weekly in Britain’s electricity infrastructure. We supply millions of customers with electricity and help homes and businesses switch to electricity for heating, transport and industrial processes.
We operate five nuclear power stations and more than 35 onshore wind farms and three offshore wind farms. Since 2009, EDF has invested almost £9 billion in the nuclear fleet to improve reliability and extend station lifetimes. The five generating stations currently supply about 12% of the UK’s electricity demand.
EDF is building the UK's nuclear renaissance with the construction of a new nuclear power station at Hinkley Point C. We are a minority investor (12.5%) in and major supplier to a replica plant at Sizewell C in Suffolk. Hinkley Point C and Sizewell C will provide low carbon electricity to meet 14% of UK demand and power around 12 million homes. EDF Group companies Framatome and Arabelle Solutions have a presence in the UK and manufacture critical equipment such as reactor pressure vessels and turbines.
EDF is enabling its 5 million customers, both in business and at home, to choose electric solutions that save cash and carbon, whether it is buying an electric car, generating and storing electricity, selling energy back to the grid or installing solar panels or a heat pump. In 2025, EDF’s Customers business was ranked as one of the Sunday Times’s Best Place to Work.
It is also one of the UK’s leading developers of renewable energy through EDF power solutions UK and Ireland. We have more than 2GW of renewable generation in operation and over 10GW in construction, planning and development across a range of technologies including onshore and offshore wind, solar and battery storage.
We are one of the largest suppliers to British business and a leading supplier of innovative energy solutions that are helping businesses become more energy independent. In addition, the company’s energy services business, Dalkia, is one of the UK and Ireland’s largest technical service providers.
About BW ESS
BW ESS is a global energy storage developer, owner and operator, moving with speed to develop and build market-leading energy storage projects across multiple countries.
The business is active in the UK, Australia, Italy, Germany, Spain, and Sweden. It has more than 540MWh of operating BESS projects, with ~11GWh under /pre-construction and a development pipeline of about 8GW.
BW ESS has a strategy to hold assets for the long-term, taking a hands-on approach to unlock value throughout the energy storage asset lifecycle.
Part of BW Group, BW ESS can leverage a global industry network, as well as decades of experience in energy infrastructure investment, delivery, and operation.
Media contacts:
Tamarindo Communications
bwess@tamarindo.global
About AIP Management
AIP specialises in decarbonisation and energy infrastructure investments that facilitate the energy transition in Europe and North America. Our team comprises 80 professionals with extensive expertise in investments and energy working from Copenhagen, London, Madrid, and New York. To date, AIP has invested over €8 billion in infrastructure assets. This includes renewable energy assets with a capacity of approximately 9 GW. Once fully operational, AIP’s investments will contribute to avoiding 17.8 million tons of greenhouse gasses and support about 9 million households with renewable electricity. AIP is part of Storebrand, a Nordic financial group, which owns 60% of AIP.
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