UK energy utility UK Power Networks on December 2 announced the success of a two-year trial of the largest grid-scale battery in Britain, 6MW, which it says could transform the energy grid and play a major role in the transition to a low-carbon economy.

The Smarter Network Storage facility at Leighton Buzzard, Bedfordshire, was designed by S&C Electric, a Chicago, US-based electric power systems designer that used 50,688 individual Samsung SDI lithium-ion cells with a total energy capacity of 11.2 MWh.

The £18.4 million ($23.4 million) 6MW/10MWh facility – which is the size of three tennis courts and can store enough electricity to power 6,000 homes for 1.5 hours at peak times – has supported the National Grid for more than 7,500 hours and has fed the electricity network 180 times, according to Jenny Chapman, a spokesperson at UK Power Networks.

“The SNS facility was the first multi-purpose grid-scale battery system providing both support to the distribution network operators and ancillary services to National Grid. When first energized it was the largest utility battery in Europe and doubled the total GB DNO connected battery storage,” she said.

Much of the funding for the project came from Ofgem, the UK government power regulator, which awarded £13.2 million from its Low Carbon Networks Fund. UK Power Networks added £4 million and ‘other project partners’ made up the rest.

“We are anticipating that we will get over 10 years’ use before the battery capacity will have dropped sufficiently that it no longer meets our needs,” said Chapman.

“This trial was set up to not only prove that the technology works but analyze the commercial and regulatory barriers that storage has. Our contribution to the project is part of this wider goal. The immediate benefits of implementing this solution is network reinforcement deferral, but the contribution the project has made to the industry has also been very important.”

Suleman Alli, director of safety, strategy and support services at UK Power Networks said: “As we move towards a low-carbon, decentralized, digital energy system, all eyes are on the role of storage — especially batteries — in Britain’s electricity network. We believe that grid-scale storage has a huge role to play in addressing the challenges the industry faces.

“The trial has drawn attention to the fact that the UK’s regulatory framework needs to evolve to help exploit its full potential. For example, energy storage currently incurs a double carbon levy — both when it stores energy and when it releases it.”

“The primary application of the system is peak shaving,” said S&C’s EMEA Business Unit sales director Cleverson Takiguchi. “The system is also able to derive value from additional services such as dynamic firm frequency response, static firm frequency response, enhanced frequency response, voltage control, wholesale electricity market tolling, reactive power support as well as short term operating reserve.

“The project successfully demonstrated the commercial operation of a large-scale energy storage asset.”

The Leighton Buzzard facility is unlikely to remain the largest of its kind in the UK for long.

Planners at Dormington, Herefordshire, have just granted approval for a 20MW battery storage system that will be designed by the Brighton-based developer Energy Reservoirs, which is contracted to complete construction within three years.

A decision has not yet been made as to which batteries will be installed.