EnergyPathways has submitted a formal gas storage licence application to the North Sea Transition Authority (NSTA) for its flagship EnergyPathways MESH Project — the Marram Energy Storage Hub — an integrated energy storage facility in the East Irish Sea targeting up to 60 large-scale salt caverns for hydrogen and natural gas storage. The project has been designated a development of national significance by UK Energy Secretary Ed Miliband under Section 35 of the 2008 Planning Act, unlocking a streamlined consent process and signalling strong government backing.
What Is the EnergyPathways MESH Project?
MESH stands for Marram Energy Storage Hub, located offshore in the East Irish Sea off the coast of Cumbria and Lancashire in Northwest England. The project is designed as a fully integrated energy system combining long-duration energy storage (LDES), natural gas storage, hydrogen storage, offshore wind connectivity, and decarbonised power generation — all operating from a single offshore hub.
If developed to full scale, MESH would be capable of storing in excess of 500 million therms of energy, making it the largest natural gas and hydrogen storage facility in the UK. Production operations are targeted to begin from late 2027, subject to licensing and planning approvals.
The project directly addresses one of the UK’s most acute infrastructure weaknesses. As CEO Ben Clube has noted publicly, the UK currently holds just 12 days of gas storage — compared to Germany, the Netherlands, Italy and France, which each hold approximately ten times that capacity. With around half of the UK’s remaining storage potentially facing closure, the gap is becoming strategically critical. For further context on why storage security is now a policy priority, see our analysis of why UK energy security now depends on strategic storage.
The Licensing Milestone and National Significance Designation
The road to the current licence application was not straightforward. The NSTA initially declined to grant a gas storage licence to MESH in August 2025 — a decision that hit EnergyPathways’ share price hard. However, the company’s fortunes shifted significantly in September 2025 when Miliband confirmed the MESH Project as nationally significant, enabling progression under a Development Consent Order (DCO) process that bypasses the standard licensing route and reduces approval risk.
Following that designation, EnergyPathways received NSTA consent to apply for new hydrogen and natural gas storage licences. The nominated area for these new applications covers four times the salt cavern storage potential of the company’s original submissions — a significant expansion in scope that reinforces the project’s long-term ambition.
The formal storage licence application has since been submitted, covering both natural gas storage through the Knox and Lowry gas fields, and hydrogen storage elements approved through the Department for Energy Security and Net Zero (DESNZ). This positions the EnergyPathways MESH Project as one of the most advanced large-scale storage development applications in the UK.
Technology Partners and Hydrogen Production Plans
EnergyPathways is developing the MESH Project alongside a group of Tier 1 engineering and technology partners. Wood plc is the lead engineering partner, while Siemens Energy is involved in the power and storage technology components. For hydrogen production, the company has entered into engineering studies with KBR Inc and Australian firm Hazer Group, with those studies expected to complete in early 2026.
The hydrogen production element targets an initial capacity of 20,000 tonnes per year, using Hazer’s proprietary methane pyrolysis process — sometimes referred to as turquoise hydrogen — which converts methane into clean hydrogen without emitting carbon dioxide. A notable by-product of the process is synthetic graphite, targeting production of around 60,000 tonnes per annum. With the UK entirely dependent on imports for its graphite supply and China controlling over 80% of global production, this by-product stream carries significant strategic value beyond energy storage alone.
The project also incorporates EnergyPathways’ own proprietary hybrid compressed air energy storage (H-CAES) system, which uses both diabatic and adiabatic technologies to optimise multi-day energy storage while minimising fuel consumption. This positions MESH as a genuinely integrated facility rather than a single-technology storage play. The scale and technology breadth of MESH draws comparison with the broader infrastructure buildout covered in our 2026 LNG storage infrastructure analysis.
The Wind Curtailment Problem MESH Is Built to Solve
A core commercial rationale for the EnergyPathways MESH Project is the UK’s rapidly worsening wind curtailment problem. In 2025, approximately £1.5 billion was added to consumer energy bills as a direct result of surplus wind power that could not be absorbed by the grid — wind farms paid to shut down while the power went to waste. Government projections suggest that figure could reach £6–8 billion annually by 2030 as offshore wind capacity continues to expand without corresponding storage infrastructure.
MESH is designed to capture that surplus power during periods of high wind output and release it as stored energy when demand peaks — providing multi-day storage at competitive cost. This aligns directly with the UK government’s Clean Power 2030 strategy, which requires large-scale flexible storage to make an increasingly wind-heavy grid reliable and affordable. The broader challenge of underground storage as energy insurance is explored in our 2026 underground gas storage outlook.
What Comes Next for the MESH Project
EnergyPathways is now focused on finalising the licensing process, progressing planning approvals through the DCO route, and securing Tier 1 offtake partners for the energy and hydrogen output. An international partnership with Siemens Energy is also reported to be in development, with ambitions to scale the technology platform beyond the UK market.
The project’s modular design — expandable to 60 salt caverns — gives MESH a long development runway, with the potential to grow incrementally as licences are secured and financing is confirmed. EnergyPathways has confirmed it has received expressions of interest for project financing, though investment levels for full development have not been publicly disclosed.
With national significance status confirmed, the storage licence formally submitted, and engineering studies advancing with KBR and Hazer, the EnergyPathways MESH Project enters 2026 at its most advanced stage yet — and as one of the few large-scale, long-duration storage projects anywhere in Europe with genuine government-level backing and a credible technical pathway to delivery.
What is the EnergyPathways MESH Project?
MESH stands for Marram Energy Storage Hub, an integrated offshore energy project in the East Irish Sea developed by EnergyPathways PLC. It combines natural gas storage, hydrogen storage, long-duration compressed air energy storage, and decarbonised power generation in a single hub off the coast of Cumbria and Lancashire.
Why has the MESH Project been designated nationally significant?
UK Energy Secretary Ed Miliband confirmed MESH as a development of national significance under Section 35 of the 2008 Planning Act in September 2025. This designation enables the project to progress through a Development Consent Order process, streamlining planning approvals and reducing licensing risk — a reflection of the project’s strategic importance to UK energy security and the Clean Power 2030 strategy.
How large is the EnergyPathways MESH Project?
At full scale, MESH could incorporate up to 60 large-scale salt caverns and store in excess of 500 million therms of energy, making it the UK’s largest proposed natural gas and hydrogen storage facility. The latest licence application covers a nominated area four times larger than EnergyPathways’ original storage submissions to the NSTA.
Who are EnergyPathways’ partners on the MESH Project?
EnergyPathways is working with Wood plc as lead engineering partner, Siemens Energy on power and storage technology, KBR Inc and Hazer Group for hydrogen production engineering studies, and Costain plc and Zenith Energy as additional project partners. Hazer’s methane pyrolysis technology will be used to produce turquoise hydrogen and synthetic graphite as a by-product.
When is the EnergyPathways MESH Project expected to begin operations?
EnergyPathways is targeting production operations to begin from late 2027, subject to the necessary licences being granted and planning approvals progressing through the DCO process. Engineering studies with KBR and Hazer were expected to complete in early 2026, in line with the project’s pre-FEED timeline.