The UK Is Building Its First Hydrogen Network. The Secondary Specification for Hydrogen Infrastructure Is FRP.
The UK government has committed over £500 million to develop the first regional hydrogen transport and storage network. EET Hydrogen begins production at Stanlow in 2026. Cadent is constructing 100 kilometres of hydrogen pipeline through the HyNet North West cluster. The national target is 10GW of low-carbon hydrogen production capacity by 2030. Hydrogen infrastructure creates a secondary specification environment that is unlike any other in UK energy construction: hydrogen gas is the smallest molecule that exists, it embrittles steel over time, it ignites at concentrations as low as 4% in air, and its explosive atmosphere zones extend well beyond the immediate process boundary. FRP is the secondary structural material that the hydrogen environment demands — non-sparking, non-conductive, hydrogen-compatible, and maintenance-free across the design lives of the facilities it serves.
Published by Reinforce Technology | 10 September 2026
The UK hydrogen sector is moving from policy to physical construction. EET Hydrogen's plant at the Stanlow Manufacturing Complex in Ellesmere Port, the first plant in the HyNet North West cluster, is designed to produce 350MW of low-carbon hydrogen from 2026, with a second plant scaling to 1,000MW to follow (Norton Rose Fulbright, 2025). Cadent's HyNet North West Hydrogen Pipeline will deliver 100 kilometres of new underground pipeline transporting 100% low-carbon hydrogen from Stanlow to industrial offtakers across Cheshire and Lancashire (HyNet, 2026). The government's July 2025 hydrogen market update confirmed over £500 million to enable the development of the first regional hydrogen transport and storage network, with a target to connect producers with industrial users, power generation, and storage facilities for the first time (GOV.UK, 2025).
The national target of 10GW of low-carbon hydrogen production capacity by 2030, with at least 5GW electrolytic, creates a construction pipeline that extends well beyond the HyNet cluster. The Hydrogen Allocation Rounds 3 and 4 in 2025 and 2026 are allocating capacity to electrolytic production projects across the UK's coastal and offshore wind-adjacent regions, with each allocated project entering construction on a timeline determined by its specific planning, grid connection, and funding structure. The government has temporarily waived licensing requirements for pipelines transporting 100% hydrogen as of July 2025, designed to accelerate the development of hydrogen infrastructure by reducing regulatory barriers for pilot and early-stage commercial projects (Baker McKenzie, 2025).
Each hydrogen production facility, each hydrogen pipeline corridor, and each hydrogen storage facility in this growing programme creates secondary infrastructure specification decisions in an environment that is fundamentally different from conventional energy infrastructure. The properties of hydrogen that create its value as a clean energy carrier are also the properties that make the secondary infrastructure specification of hydrogen facilities a more specific and more consequential decision than secondary specification in most other energy applications. Getting it right requires understanding why hydrogen infrastructure is different, and why FRP is the secondary material that the hydrogen environment consistently demands.
Why Hydrogen Infrastructure Is Different
Hydrogen is the smallest and lightest molecule in existence. Its molecular diameter is approximately 0.289 nanometres, compared with 0.372 nanometres for methane. This size difference has significant practical consequences for infrastructure: hydrogen leaks more easily than methane through seals, fittings, and material microstructure, can permeate through polymer membranes that contain other gases effectively, and concentrates in enclosed spaces more rapidly than heavier gases because it rises and accumulates at high points in buildings and structures. Hydrogen detection and ventilation requirements in hydrogen facilities are therefore more demanding than in equivalent natural gas installations, and the explosive atmosphere zones generated by hydrogen release events extend over larger areas and include more of the facility's superstructure than equivalent natural gas zones.
The lower explosive limit of hydrogen in air is 4%, compared with 5% for methane. This means hydrogen becomes flammable at lower concentrations than any other common fuel gas. The upper explosive limit is 75%, giving hydrogen a flammable range of 4% to 75% by volume in air — far wider than methane's 5% to 15% range. The combination of a low LEL, a wide flammable range, very low minimum ignition energy (approximately 0.017 millijoules versus 0.28 millijoules for methane), and a flame that is invisible in daylight makes hydrogen one of the most demanding explosive atmosphere management challenges in industrial process safety. ATEX zone classification in hydrogen facilities consistently produces Zone 1 and Zone 2 classifications across larger areas of the facility than equivalent natural gas or LPG processing environments (IntechOpen, 2022).
The minimum ignition energy of hydrogen is the critical property for secondary infrastructure specification. At 0.017 millijoules, hydrogen can be ignited by electrostatic discharge, by the spark generated by impact between hard materials, or by the friction spark from metal-to-metal contact under load. Secondary structural materials in hydrogen facilities that can generate sparks under mechanical impact, friction loading, or accidental contact with tools and equipment present a specific ignition risk in Zone 1 and Zone 2 classified areas that the ATEX framework requires to be eliminated through equipment selection and material specification. FRP is non-sparking under all mechanical impact and friction loading conditions encountered in normal and foreseeable accidental operations in a hydrogen facility, eliminating the ignition risk from the secondary structural access infrastructure in ATEX classified zones.
The Hydrogen Embrittlement Challenge for Steel
Hydrogen infrastructure creates a specific and well-documented degradation mechanism for steel that does not affect FRP: hydrogen embrittlement. When atomic hydrogen diffuses into the crystal lattice of steel under pressure or in corrosive environments where hydrogen evolution occurs at the steel surface, it reduces the ductility and fracture toughness of the steel, making it susceptible to brittle fracture at stress levels well below the material's normal yield strength. Hydrogen embrittlement is a documented failure mechanism for high-strength steel components in hydrogen service, and its management requires specific material selection, heat treatment specifications, and operating condition controls that add complexity and cost to hydrogen facility engineering.
FRP does not experience hydrogen embrittlement. The glass fibre and polymer resin matrix of FRP has no metallic crystal lattice for atomic hydrogen to diffuse into, no mechanism for hydrogen-induced reduction of fracture toughness, and no susceptibility to the brittle fracture failure mode that hydrogen embrittlement creates in steel. In the process environments of hydrogen production facilities where hydrogen gas is present at elevated pressures and temperatures in close proximity to secondary structural elements — piping supports, equipment base frames, access platforms around pressure vessels — the absence of hydrogen embrittlement susceptibility in FRP is a specific material advantage over steel that is independent of the corrosion resistance and electrical non-conductivity arguments that apply across all FRP applications (GOV.UK, 2025).
Where FRP Is Specified in Hydrogen Infrastructure
1. Access Platforms and Grating in ATEX Classified Areas
The process areas of an electrolytic hydrogen production facility — the electrolyser halls, hydrogen drying and purification equipment areas, and hydrogen compression train areas — are ATEX classified environments where the potential for hydrogen release during normal operation and foreseeable process upsets creates Zone 1 or Zone 2 explosive atmosphere classifications across the working areas where maintenance and operational personnel access the equipment. FRP moulded grating for access platforms in these areas is non-sparking under foot traffic, tool drop, and the mechanical impact of maintenance operations, satisfying the ATEX equipment category requirements for secondary structural access infrastructure in Zone 1 and Zone 2 hydrogen environments.
Steel grating in hydrogen ATEX zones requires assessment under the ATEX framework for its potential to generate incendive sparks under impact loading. While correctly specified steel grating with smooth top surfaces can be assessed as acceptable in some Zone 2 applications, the conservative approach in Zone 1 classified areas is to specify non-sparking materials throughout, and FRP moulded grating is the established non-sparking access surface for ATEX Zone 1 classified process areas across the UK's chemical and gas processing industry (IntechOpen, 2022).
2. Cable Management for Electrical Infrastructure
Hydrogen production facilities have substantial electrical infrastructure: the power supply for electrolysers, which consume large quantities of electrical power to split water into hydrogen and oxygen; the motor drives for compression, cooling, and drying systems; the instrumentation and control systems that govern the safety and process management of hydrogen production; and the emergency power systems that maintain safety-critical functions during grid supply interruptions. The cable management routing this electrical infrastructure runs through the same process areas as the secondary access infrastructure, in the same ATEX classified environments.
FRP cable trays in hydrogen facility electrical infrastructure are non-conductive throughout, eliminating the earthing and bonding programme that metallic cable management requires in proximity to all electrical systems. Non-conductive FRP cable management also eliminates the risk of a conducted fault current path through the cable management structure in the event of an electrical fault, removing a potential ignition source in the hydrogen ATEX zone that metallic cable management cannot eliminate without additional earthing and bonding protection measures. The combination of non-sparking structural behaviour and non-conductive electrical properties makes FRP cable management the correct specification for cable routing in hydrogen production facility ATEX zones.
3. Structural Profiles for Equipment and Pipework Supports
The secondary structural framing of a hydrogen production facility, including the supports for hydrogen piping, the base frames for compression and drying equipment, and the structural mounts for electrical distribution equipment in process areas, operates in the close proximity to hydrogen process equipment that creates the most demanding ATEX zone classifications in the facility. FRP pultruded structural profiles for equipment and pipework supports in hydrogen facility process areas provide non-sparking structural sections that do not generate ignition risk under the mechanical loading of normal operational conditions, maintenance activities, or the foreseeable accidental loading of tool impact and vibration from adjacent rotating equipment.
The non-magnetic property of FRP structural profiles is also relevant in the process areas of electrolytic hydrogen production facilities, where the strong magnetic fields generated by the direct current bus bars supplying the electrolysers can interact with ferromagnetic secondary structural elements in close proximity, generating induced currents and localized heating that the magnetic field management of the electrolyser system must account for. FRP structural profiles generate no interaction with the DC bus bar magnetic fields, simplifying the electromagnetic management of the electrolyser environment.
4. Perimeter Fencing for Hydrogen Storage and Production Sites
Hydrogen production and storage facilities require perimeter fencing that satisfies the non-sparking requirement in the explosive atmosphere zones that extend to or beyond the facility boundary, while also providing the physical security of a high-security energy infrastructure installation. FRP perimeter fencing posts, rails, and mesh panels are non-sparking under all mechanical impact conditions including vehicle impact at the perimeter boundary, satisfying the ATEX zone requirement for non-sparking secondary materials at the perimeter of hydrogen facilities where Zone 2 explosive atmosphere classifications extend to the facility boundary under worst-case hydrogen release scenarios.
FRP perimeter fencing also carries zero scrap metal value, eliminating the secondary theft incentive that steel perimeter fencing creates at remote and semi-rural hydrogen production and storage sites, and avoiding the earthing and bonding requirement that steel fencing in the electrical environment of a hydrogen facility's perimeter would demand (IntechOpen, 2022).
The HyNet Pipeline and the Pipeline Infrastructure Secondary Specification
Cadent's HyNet North West Hydrogen Pipeline, 100 kilometres of new underground pipeline transporting 100% low-carbon hydrogen from Stanlow to industrial offtakers, creates a secondary infrastructure specification requirement along the full pipeline corridor: valve station buildings, pig launcher and receiver installations, cathodic protection monitoring stations, and the access infrastructure of above-ground structures associated with the underground pipeline route. These above-ground installations create localised hydrogen ATEX zones around flanged connections, valve stem seals, and pressure measurement tappings where hydrogen release is a foreseeable event during normal pipeline operation and maintenance.
FRP secondary structural profiles, grating, and cable management in HyNet-type pipeline valve station and above-ground pipeline infrastructure provide the non-sparking, non-conductive, corrosion-immune secondary specification that the outdoor, semi-rural, and ATEX-zoned environments of pipeline infrastructure create. The outdoor atmospheric exposure of pipeline valve stations, frequently in agricultural and coastal environments, adds the corrosion immunity of FRP to the ATEX non-sparking requirement as a compounding specification advantage over steel in these locations.
The UK's hydrogen infrastructure construction programme is moving from policy to physical construction in 2026. EET Hydrogen at Stanlow, Cadent's HyNet pipeline, and the production facilities entering construction under Hydrogen Allocation Rounds 3 and 4 collectively create a secondary specification environment unlike any other in UK energy infrastructure: explosive atmosphere zones at the lowest LEL of any common fuel gas, hydrogen embrittlement of steel at process pressures, and minimum ignition energies lower than a static discharge from a human hand. FRP — non-sparking in Zone 1 and Zone 2 ATEX classifications, non-conductive in the DC bus and AC electrical environments of electrolytic production, hydrogen-embrittlement-immune throughout, and corrosion-free across 25-year facility design lives — is the secondary specification that the hydrogen infrastructure environment demands.
Reinforce Technology FRP Products for Hydrogen Infrastructure
Reinforce Technology supplies FRP moulded grating, pultruded structural profiles, cable trays, perimeter fencing, and drainage for hydrogen production, storage, and pipeline infrastructure across the UK. All products are non-sparking under mechanical impact and friction loading, satisfying ATEX Zone 1 and Zone 2 requirements for secondary structural materials in hydrogen facility process areas. Available in polyester and vinyl ester resin systems for the outdoor and process chemical environments of UK hydrogen infrastructure. Non-conductive throughout, with zero earthing and bonding requirements in proximity to all electrical systems encountered in hydrogen facility construction.
Contact us to discuss your hydrogen infrastructure project and the correct FRP specification for your ATEX zone classification, process environment, and operational horizon.
Final confirmation of suitability for any specific hydrogen infrastructure application, including ATEX zone classification verification and structural loading assessment, remains the responsibility of the appointed project engineer and the ATEX competent person responsible for the facility's explosive atmosphere documentation. Reinforce Technology provides technical guidance and material recommendations based on information supplied to us, but specification and safety sign-off should always sit with the qualified professionals responsible for the engineering and safety of the installation.
References
Baker McKenzie (2025) Hydrogen Developments: United Kingdom. Available at: https://resourcehub.bakermckenzie.com/en/resources/hydrogen-heat-map/emea/united-kingdom/topics/hydrogen-developments [Accessed: 10 September 2026]. [HAR3 and HAR4 allocating up to 1.5GW in 2025 and 2026; July 2025 licensing waiver for 100% hydrogen pipelines to accelerate infrastructure development].
GOV.UK (2025) Hydrogen Update to the Market: July 2025. Available at: https://assets.publishing.service.gov.uk/media/6880b2139fab8e2e86160efe/hydrogen-update-to-the-market-2025.pdf [Accessed: 10 September 2026]. [Over £500 million confirmed for first regional hydrogen transport and storage network; target to connect producers with industrial users and power generation; hydrogen embrittlement as key material consideration for steel in hydrogen service].
HyNet (2026) HyNet North West Hydrogen Pipeline. Available at: https://www.hynethydrogenpipeline.co.uk/ [Accessed: 10 September 2026]. [100 kilometres of new underground pipeline; 100% low-carbon hydrogen transport from Stanlow to industrial offtakers; Cadent Gas Ltd developer; statutory consultation October to November 2024].
IntechOpen (2022) 'Fibre-Reinforced Polymer (FRP) in Civil Engineering', in IntechOpen Engineering Series. Available at: https://www.intechopen.com/chapters/84203 [Accessed: 10 September 2026]. [Non-sparking under mechanical impact and friction; ATEX Zone 1 and Zone 2 compliance; non-conductive; non-magnetic; corrosion-immune; 25-year design life without maintenance].
Norton Rose Fulbright (2025) UK Hydrogen Guide 2025. Available at: https://www.nortonrosefulbright.com/-/media/files/nrf/uk-hydrogen-guide-2025 [Accessed: 10 September 2026]. [EET Hydrogen at Stanlow: HPP1 350MW production from 2026; HPP2 up to 1,000MW; HyNet North West CCS project; hydrogen production from waste gases and methane with CO₂ transport and storage].
ScienceDirect (2025) 'Sustainable composites for metal replacement: Environmental assessment and material selection of fiber-reinforced polymer across industries', ScienceDirect, doi: 10.1016/S2667-3789(25)00051-3. Available at: https://www.sciencedirect.com/science/article/pii/S2667378925000513 [Accessed: 10 September 2026].
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