EnergyPathways (AIM:EPP) provided investors with a progress update on the Marram Energy Storage Hub, the integrated compressed air, gas and hydrogen storage project in the East Irish Sea and Barrow-in-Furness that the UK government designated nationally significant in September 2025.
The long-duration energy storage (LDES) element, targeting 300 MW and 55 GWh of capacity, carries estimated capital expenditure of £450 million to £500 million, with scoping economics indicating annual revenues of £100 million to £200 million and EBITDA of £40 million to £120 million.
EnergyPathways has appointed Jacobs to support the project's Development Consent Order process and its submission to Ofgem's Cap & Floor round, expected to launch in the fourth quarter, and is in early talks with banks, institutional investors and offtake partners.
The gas storage element, covered by a licence awarded by the North Sea Transition Authority in July, is estimated to hold roughly 1.3 billion cubic metres of working volume, doubling UK storage from six to twelve days, with projected revenues of £100 million to £150 million and EBITDA of £50 million to £70 million annually.
The hydrogen and graphite plant, developed with Finland's Hycamite TCD Technologies alongside existing work with Hazer Group and KBR, targets output of roughly 20,000 tonnes of hydrogen and 60,000 tonnes of graphite, with estimated capital costs of £120 million to £200 million and EBITDA of £40 million to £60 million.
Combined development and capital expenditure across all three projects is estimated at £1.02 billion to £1.20 billion.
Under its April financing arrangement, EnergyPathways has drawn down £2 million of its £5 million loan note, with £500,000 converted into shares, while its £10 million at-the-market facility has issued 6.94 million shares, equivalent to 2.99% of issued share capital, all now sold into the market.
"We are now entering a critical phase in the lifecycle of all three projects," said chief executive Ben Clube, adding that engineering, regulatory and financing workstreams are progressing "at pace".
The company said further announcements will follow on Cap & Floor submission, grid connection arrangements, and completion of development expenditure funding.