National Grid has connected the UK’s largest battery energy storage system (BESS) to its transmission network at Tilbury substation in Essex.

The 300MW Thurrock Storage project, developed by Statera Energy, is now energised and delivering electricity flexibly to the network across London and the South-east.

With a total capacity of 600MWh, Thurrock Storage is capable of powering up to 680,000 homes and can help to balance supply and demand by soaking up surplus clean electricity and discharging it instantaneously when the grid needs it.

National Grid reinforced its Tilbury substation to ensure the network in the region could safely carry the battery’s significant additional load, with new protection and control systems installed to ensure a robust connection.

The substation previously served the coal-fired Tilbury A and B power stations on adjacent land prior to their demolition, so the connection of the Thurrock Storage facility marks a symbolic transition from coal to clean electricity at the site.

John Twomey, director of customer and network development at National Grid Electricity Transmission, said: “Battery storage plays a vital role in Britain’s clean energy transition. Connecting Thurrock Storage, the UK’s biggest battery, to our transmission network marks a significant step on that journey.

“Our Tilbury substation once served a coal plant, and with battery connections like this, it’s today helping to power a more sustainable future for the region and the country.”

Tom Vernon, Statera Energy CEO and founder, added: “We are delighted that Thurrock Storage is now energised, following its successful connection to the grid by National Grid Electricity Transmission. Increasing BESS capacity is essential for supporting the grid when renewable generation, such as solar and wind, is low or changes quickly. It ensures that energy can be stored efficiently and returned to the grid whenever it’s needed.”

National Grid is continuing work at Tilbury substation to connect the 450MW Thurrock Flexible Generation facility, another Statera project that is set to support the energy needs of the region.

The connection of the UK’s biggest battery follows energisation in July of the 373MW Cleve Hill Solar Park in Kent – the largest solar plant in the country – which National Grid connected to its adjacent Cleve Hill substation.