Press Release

15 June 2026

‍Apatura and Frontier Power Advance UK Long-Duration Energy Storage Through Ayr and Busby Transaction ‍‍ ‍

Ayr and Busby Transaction Marks Key Milestone for UK Long-Duration Energy Storage ‍

On 26 May 2026, Frontier Power Energy Holdings Ltd, the UK long-duration energy storage platform established by Frontier Power Ltd in partnership with affiliates of Cerberus Capital Management, L.P., acquired the rights to two long-duration energy storage (LDES) projects at Ayr and Busby from Apatura Energy.

The transaction marks an important milestone for both Frontier and Apatura, supporting the continued deployment of large-scale LDES infrastructure across the UK. The Ayr project has a planned capacity of 200 MW (1,600 MWh), while Busby will deliver 150 MW (1,200 MWh). The projects are intended to deploy long-duration battery systems supplied by Eos Energy Enterprises, Inc. (“Eos”), including its Z3™ technology platform, under the existing framework agreement between Frontier and Eos to support the development of LDES assets across the UK.

Both projects have received Gate 2 notifications under NESO’s Grid Connections Reform process, reflecting their strategic importance to the UK electricity system and their role in supporting delivery of the Government’s Clean Power 2030 ambitions. Frontier intends to advance Ayr and Busby as part of its UK long-duration energy storage portfolio, with a view to participation in Ofgem’s Cap and Floor regime.

For Frontier, the acquisitions form part of its strategy to build one of the UK’s largest LDES portfolios. The company has assembled a 2.6 GW / 20 GWh UK pipeline designed to deploy long-duration battery storage at scale and to underpin a broader UK investment programme in long-duration energy infrastructure.

For Apatura, the transaction represents the next phase in the development of two strategically important assets it has originated and progressed. Apatura will retain an active role in the ongoing development of the sites, working alongside Frontier to advance them through to delivery.

Apatura CEO Giles Hanglin commented:

“This transaction reflects the progress at Ayr and Busby and marks the next step in their development, and we’re pleased to remain involved as the projects move forward with Frontier. Long-duration energy storage has an important role in strengthening energy security and supporting a more resilient, low-carbon energy system.”

Humza Malik, CEO of Frontier Power, said:

“Ayr and Busby are excellent additions to our portfolio, and we look forward to working with Apatura as they progress. We continue to see significant opportunities for long-duration energy storage in the UK and remain focused on bringing forward projects capable of delivering energy security, economic growth and long-term system resilience.”

Joe Mastrangelo, Chief Executive Officer of Eos, said:

“We continue to build upon our relationship with Frontier as they advance long-duration energy storage opportunities across the UK. The selection of Eos Z3 technology for projects such as Ayr and Busby reflects the growing recognition of-long duration energy storage as a critical component of modern grid infrastructure. As customers seek solutions that enhance grid reliability and energy security, we believe Eos is uniquely positioned to address those needs with a safe, scalable and purpose-built technology.”

Subject to successful participation in Ofgem’s Cap and Floor regime, Frontier’s wider portfolio could unlock up to £5 billion of UK investment, create up to 1,900 skilled jobs, and support thousands more across manufacturing, engineering, and the wider supply chain.

Ends