Future extension to around 1,750 MWh in total capacity is included in approval granted for the Hams Hall location.
With partners Luminous Energy, the Clapham-based developers have earmarked a spot permitting a 350 MW grid connection.
The pair will operate the unit under their Wiltshire-registered joint-venture banner Welbar Energy Storage.
Hams Hall is part of a large pipeline of Penso projects receiving funding from BW Group, the privately held marine transport and engineering firm, under a commitment made last October. Penso Power, Luminous Energy and BW Group will become joint shareholders in the Warwickshire development, with Penso Power managing it once operational.
Former investment banker Richard Thwaites founded Penso Power in 2018, having quit the chairmanship of rival Limejump on its purchase by Shell.
In 2020 Penso originated Britain’s then biggest battery, the 100MW, two-site project in Minety, Wiltshire. Investors China Huaneng Group were later recruited, contributing funds to extend it by a further 50MW.
Of Hams Hall, Thwaites welcomed planning approval for what he called “an important project in our three-gigawatt pipeline”.
“This project is globally significant in scale”, said Thwaites today. “We expect it to play an important role in ensuring the resilience of the UK’s electricity system.”
David Bryson of Luminous Energy said: “From our initial site selection through the planning process we have worked closely with the local planning authority, National Grid and local groups.
“Now more than ever the UK needs to take back control over its energy supply. Energy storage is critical in supplying affordable, clean power, while also enhancing the UK’s grid reliability”, Bryson declared.
BW Renewables managing director Erik Strømsø congratulated the partners on the project’s successful development, a “milestone” in the partnership.