Long-duration energy storage need in GB could mostly be met by lithium-ion, investor says

LinkedIn
Twitter
Reddit
Facebook
Email

“We need to allow the technology to show us what the most cost effective solution for is 10-20-hour duration energy storage is”, managing director of Adaptogen Capital James Mills says.

Speaking on a panel at the Energy Storage Summit in London today, Mills said that in the long term, storage and batteries are the “only way” to solve the “massively complex” green grid due to be established by 2040.

While governments are currently primarily focused on the clean power targets set for 2030, continuing on to meet legally binding 2050 carbon reduction targets will require significant battery storage deployment, the panel agreed.

Paul Wakely, head of strategic network development at the UK’s National Energy System Operator (NESO), said batteries are important “in all time scales—it is now part of our daily life in the energy system”.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

Florent Xavier, director of R&D partnership, valorization and transformation for French transmission operator Réseau De Transport D’Electricité (RTE), said flexibility to enable security of supply is the “main one” in France, where over 5GW flexibility is needed to support the network by 2030.

Meanwhile, David Noronha, head of future networks & strategic offshore planning for Irish grid operator EirGrid, said in Ireland long-duration energy storage (LDES) is crucial to supporting the network of the future, but for all storage it “boils down to location”; the impact storage brings is “dependent on its location in the network”.

This was also the opinion of Andy Willis, CEO and co-founder of UK-based battery energy storage developer Kona Energy. The focus, according to him, should be on developing storage, in the short and long term, in areas that it can solve constraints. To enable batteries to thrive in this scenario, though, Willis said there needs to be proper renumeration: “There is a locational need for batteries, but their value is not being realised.”

Mills took this on, noting that there are two key issues for the grid of 2040: massive constraint complexity and the volume of terawatt-hour duration that the system will need.

“I feel for the transmission owners the green grid of 2040 will be massively complex in a mathematical sense. I don’t think it can be solved from the centre, [the system] can only optimise itself and remain stable if you allow co-optimisation in real time through price.

“My vision is that we will end up with a system of massively distributed BESS at almost every gap.”

Longer duration lithium

Although duration will necessarily increase, Mills said that, cost-wise, it is most likely that this will be realised using lithium-ion battery technology in the most part. There is “no doubt” that the difference between the energy system of today and the system of 2030-40 will be that “we need to push battery storage into 10h+ duration”.

For Mills, this is entirely feasible: “The rate of change in BESS technology and the cost curve is extraordinary.”

8 September 2026
Barcelona, Spain
Battery & Energy Storage Tech Europe (BESTE) is Europe’s industrial scaling platform for stationary and industrial battery applications — not EVs. Taking place 8–9 September 2026 at Fira de Barcelona, BESTE brings together utilities, IPPs, energy-intensive industries, data centres, ports, rail, maritime, defence and aerospace OEMs — all deploying or integrating battery storage at scale. Over 100 companies already confirmed — including EDP Renewables, Acciona, Endesa, Naturgy, Neoen, Galp, Basquevolt and Veolia — alongside 40+ expert speakers and international institutional support from BEPA, BVES, LDES and Volta Foundation. Where Europe’s battery & ES ecosystem turns projects into reality.
15 September 2026
San Diego, USA
You can expect to meet and network with all the key industry players again in 2025 from major US asset owners, operators, RTOs and ISOs, optimizers, software and analytics providers, technical consultancies, O&M technology providers and more.
13 October 2026
London, UK
Now in its second edition, the Summit provides a dedicated platform for UK & Ireland’s BESS community to share practical insights on performance, degradation, safety, market design and optimisation strategies. As storage deployment accelerates towards 2030 targets, attendees gain the tools needed to enhance returns and operate resilient, efficient assets.

Read Next

July 31, 2026
Thermal energy storage (TES) technology provider Antora Energy has closed a US$550 million Series C funding round to accelerate deployment of its thermal battery storage systems for industrial facilities and data centres in the US.
July 31, 2026
Environmental services company Veolia has been selected to operate and maintain a 350MW microgrid to power an AI data centre campus in New Albany, Ohio, US, which includes a 430MWh BESS.
Premium
July 31, 2026
We caught up with Peter Kavanagh, CEO of BESS developer Harmony Energy, after it was acquired by Switzerland-headquartered power group Alpiq. 
July 30, 2026
Infrastructure and construction company Aecon Group has executed an agreement with Ontario’s Independent Electricity System Operator (IESO) for the 150MW/1,200MWh Simcoe energy storage project in Norfolk County, Ontario.
July 30, 2026
IPP Eolian has begun construction on Flint Grid, a 200MW/1.06GWh energy storage project in Jersey Township, Licking County, Ohio, US.