Future Energy Networks

This project aims to develop a means of forecasting gas quality at the NTS offtakes, which will support current arrangements for target Calorific Value (CV) setting, allowing networks to more accurately provide target CVs to biomethane producers and reducing sudden changes in targets sent to biomethane sites which can cause operational problems. Going forward gas quality information on CV and potentially Wobbe will also assist the GDNs in managing hydrogen blend.

The Phase 3 project on gas inhibitors for hydrogen pipelines aims to translate lab-scale findings into practical applications for the UK’s National Transmission System. It focuses on validating the effectiveness of oxygen and alternative inhibitors in mitigating hydrogen embrittlement, addressing unresolved safety and integrity concerns from previous phases, and designing a plan for safe integration into existing infrastructure. The project includes physical demonstration planning, and network design to assess technology implementation.

This project will entail a feasibility study to assess the viability of developing a secure, scalable, and interoperable data sharing infrastructure for National Gas Transmission (NGT), supporting regulatory compliance, stakeholder access, and alignment with NESO’s DSI initiative. The main objective is to gain a better understanding of how we share data currently and how this will change moving forward both within established participants and enabling new participants and stakeholders to benefit from National Gas’s data. This will support the wider NESO led DSI initiative. Using two NGT data systems as a use case for this study

Repurposing of natural gas pipelines made of carbon steel for use with hydrogen blends requires a fitness-for-service analysis as part of the hydrogen use safety case. Girth welds of an unknown quality exist in the Local Transmission System (LTS). In hydrogen service these welds would have a greater susceptibility to fracture failure due to material embrittlement caused by interaction of steel material with hydrogen.

Current in-line inspection methods do not routinely inspect girth welds for defects. This project aims to test the available technology for its capability to detect defects and cracks in girth welds. This will provide valuable data for engineering critical assessments required to repurpose natural gas pipelines. It will also inform about the state of art inspection techniques and whether they can be used as a tool for repurposing pipelines.

This project will focus on barholing operations conducted after an emergency gas escape within the H100 Fife Distribution Network Operations. The scope will consider H100 scenarios, specifically the establishment of a new distribution network to deliver Hydrogen to selected properties in the conversion area. The minimum pressure for the H100 Fife Distribution network is 27 mbar, and the maximum pressure is 75 mbar. The aim of this project is to provide further evidence to support SGN operations on the H100 distribution network during emergencies and any future trials or broader rollouts of Hydrogen.

Steer Energy has been identified as a suitable contractor for executing this project due to their extensive expertise in this field and their previous work on the Barhole Trials and ITL Haldane Drill Isolator project. Steer has a proven partnership with SGN and the wider gas industry, offering a variety of services, including experimental lab testing, training, and testing facilities.

This project will explore the feasibility of integrating hydrogen train refuelling infrastructure to support the development of a hydrogen rail network. This has particular relevance to our network as some of the UK’s hardest to electrify rail routes are situated in Wales and South West England. The project will focus on these hard to electrify routes, exploring H2’s potential role in enabling their decarbonisation. If successful, this project can help the WWU network to become a proving ground for real-world delivery of impactful H2 rail technology. It is expected to provide information which can be used in planning strategic hydrogen pipeline routes and network repurposing plans, and support regional energy planning.

National Gas Transmission (NGT) own and operate the UK’s National Transmission System (NTS), transporting natural gas from terminals to end users. NGT have ambitions to repurpose the existing to transport hydrogen and hydrogen blends. Understanding the impact of hydrogen on our existing assets is a key enabler for this.

This project will conduct design of flare for hydrogen and its blends and vent system for hydrogen, its blends and carbon dioxide and offline physical testing to provide evidence that hydrogen / hydrogen blends could be flared and vented safely and environmentally in for NTS.

This project will produce valuable insights into understanding the relationship between human behaviours and the utilisation of safety devices with automated functionality. This follows the work done on hydrogen risk mitigations which included technology such as hydrogen detectors with automated functionality to remotely notify the emergency call centre to dispatch an engineer to the detected leak. In their review of this work, HSE have asked if the assumption that consumers will continue to act the same, knowing the device will be doing some automated, will change the validity of the modelling assumptions. This project will address that query and build on our own understanding of consumer insights; something which could add a depth of value to other projects exploring automated safety systems.

The National Transmission System (NTS) pipelines employ a number of external corrosion barrier coatings, primarily coal tar enamel and fusion bonded epoxy (FBE). Cathodic protection is deployed on the network to mitigate for coating failure. Additionally, there are a range of pipeline steels that are used in both above ground buried pipework, both stainless and carbon steels of various grades.

Following the previous NIA project: Research the Impact of Hydrogen on CP & Degradation of Coatings (NIA NGGT0191), the HSE have recommended follow-on testing to fully explore the impact of hydrogen permeation through steel pipelines on corrosion protection systems.

Additionally, the impact of hydrogen on all credible pipeline corrosion mechanisms is to be considered to understand whether current assumptions with regards corrosion rates are valid for hydrogen pipelines.

The National Transmission System (NTS) uses dry scrubbers, filters and strainers to remove contaminants in the gas stream. Introducing hydrogen raises new challenges due to its distinct properties, which could affect the performance and efficiency of these existing cleaning assets. We completed a project that investigated the compatibility of these assets with hydrogen and hydrogen blends to ensure gas quality without compromising the safety or efficiency. An outcome was to get a deeper understanding of the fracture and fatigue behaviours of these equipment to better understand whether hydrogen will impact the material properties. This assessment will undertake a targeted CTR analysis to inform a future potential physical test programme.

Project will deliver strategic analysis and recommendations to support the accelerated adoption of Hybrid Heat Systems (HHS) in GB. This includes assessing technology options, commercial models, stakeholder perspectives, and system integration pathways. The work will result in actionable insights, clear positioning of HHS within the wider decarbonisation strategy.

This Network Innovation Allowance (NIA) project investigated dew point management in hydrogen/natural gas blends, pure hydrogen and carbon dioxide transmission pipelines. In the National Transmission System (NTS), which is currently a natural gas network, the purity of the gas is carefully controlled via the network entry specification. Trace components, such as water, nitrogen oxides, sulphur containing compounds, oxygen and carbon dioxide have strict limits on their allowable levels in the network. This is done in part to ensure the gas delivered to end users meets the requirements of the customer, but also to protect transport and storage systems. Purity specifications are being developed for hydrogen, its blends with natural gas, and for carbon dioxide (CO₂). This project focused specifically on the water content within these gases, in what concentrations it is likely to be acceptable, the conditions at which it may condense in the network, its interactions with other trace components and contaminants and the potential detrimental effect on the network.

Limiting moisture content and ensuring gas dryness is important for several reasons:

• Safety & Efficiency: Hydrogen’s efficiency as a fuel can be compromised by moisture. Water in hydrogen can affect the combustion process, leading to a reduced efficiency for applications like gas turbines.
• Corrosion: If dew points aren’t controlled effectively, liquid can drop out of the gas phase, and this moisture can cause corrosion in pipelines and hydrogen embrittlement. For CO₂ pipelines this moisture can react to produce carbonic acid which can further corrode the pipelines.

The outcomes of the project should provide a clearer insight and strategy on how to effectively manage hydrogen and carbon dryness within the NTS, ensuring that the gas remains within the required specifications for current and future demands.

The project was split into three work packages (WP):

1. WP1 focused on hydrogen and its blends, initially reviewing the equations of state (EoS) that model the dew point temperature at varying water content and hydrogen/methane blend ratios. The impact on the network of liquid water formation in hydrogen was examined, including the interaction with other trace components such as CO₂ and H₂S, in particular the effect on welds and pipeline defects. Finally, a summary of international standards for hydrogen purity highlighted the likely water content limits that could be expected by hydrogen users and thus provided by producers.

2. WP2 focused on CO₂, its phase behaviour and the effect impurities have on this behaviour using the most appropriate equations of state. The detrimental effect of CO₂ and liquid water contained within it on pipelines, fittings and other parts of the network was reviewed.

3. WP3 focused on how the water content specifications could be managed on the network, from the point of view of monitoring and controlling water dew point in the gases. The water content expected from various production techniques were reviewed and a high-level costing for the dehydration process for both CO₂ and hydrogen was made.

This project has been initiated to assess the technical and commercial feasibility of direct hydrogen injection into the gas distribution network at 5% and 20% by volume. It supports the broader Market Frameworks appraisal by providing the evidence needed to evaluate whether both System Entry Models, direct injection and pre-blending are feasible under varying network conditions.

The need for this study was identified through the Hydrogen Blending Implementation Plan, which outlined two technical approaches for hydrogen connections: injecting hydrogen directly into the network or pre-blending it before entry, each with distinct technical and commercial implications. While National Gas has assessed both models for the transmission network, a gap analysis revealed that these findings are not directly transferable to the distribution network.

Evidence for pre-blending was previously completed as part of HyDeploy and the Hydrogen Blending Functional Specification project. It was shown that this approach provides more controlled mixing but may require more complex infrastructure, leading to higher costs for the producer. Although it is assumed Direct Injection may be achievable at lower cost, there are multiple key technical challenges associated with the technique such as the potential for inadequate hydrogen mixing, which could result in non-compliant gas, safety concerns including material integrity and operational constraints e.g. GSMR exclusion zones.

Through literature review, CFD modelling, engineering assessments, and commercial analysis, the study will evaluate the technical and safety, performance, risks, and cost implications of direct injection across a range of scenarios and configurations.

Previous testing carried out under NIA has outstanding gaps that require further testing to close. Completing the additional testing will confirm actual fracture toughness values to be used and the corresponding J value from the crack growth resistance curve. The project outputs are required and will be used to progress design, specification and procurement processes for hydrogen major projects. The results can also be applied for repurposing assessments.

To maintain their above ground and underground pipework assets, all Gas Distribution Networks (GDN) operate substantial fleets of commercial vehicles (primarily vans, but also HGVs), together with mobile plant and powered equipment. Presently, there is a complete reliance on hydrocarbon fuels, primarily diesel and petrol. Both fuel types are usually sourced via the public retail forecourt network. Similar issues exist for other utility providers that operate underground and overground infrastructure.

Wales & West Utilities is undertaking a major programme of change to support decarbonisation and deliver a hydrogen-ready, Net Zero gas network. Our distribution network iron mains replacement programme (Repex) requires significant excavation and pipe replacement activity, laying long-life, hydrogen-ready polyethylene pipe by a variety of means.

The project endeavours to identify a suite of suitable zero-emission mobile plant assets, tools and equipment for carrying out Repex work that WWU could hire or purchase for operational trials, and to identify opportunities for changing equipment items to simplify recharging/refuelling requirements in the future.

The objectives of this project are:

1. To analyse current energy demands, sound pressure and vibration levels associated with existing ICE powered mobile plant assets, ICE-powered tools and equipment and electrical equipment used for carrying out planned iron mains replacement work on the gas distribution network.
2. To estimate the future electrical energy demands (and sound pressure and vibration levels) placed by future zero-emission powered tools and equipment on a zero-emission site-based power generation facility.
3. To identify opportunities for changing equipment items to simplify recharging/refuelling requirements in future.
4. To identify a suite of suitable zero-emission mobile plant assets, tools and equipment that WWU could hire (or purchase) and utilise for operational trials, short and longer term. This will include the energy source and the means of recharging and/or refuelling on site and/or at regional depot locations.

The HIRSA programme is assessing ignition risks for the transition to hydrogen, with Stage 3 focusing on high pressure static risks including shockwave ignition and rapid adiabatic compression. This research supports the safe integration of hydrogen into gas networks.

This project aims to address major gaps identified in NIA2_SGN0078, which conducted a thorough literature review of the international scientific and industry knowledge base. The work will focus on characterising the hydrogen permeability rate of API Grades X52 and X60 vintage pipelines and welds by analysing the microstructure of each sample, investigating the impact of internal corrosion layers, and conducting mechanical testing post-exposure.

A correlation exercise will also be conducted to equate gaseous charging with electrochemical charging. The outcome of this work targets an improved industry best-practice for permeation and fracture toughness tests, providing a validated benchmark framework with the potential to inform future updates of industry standards and procedures, and saving costs on any future material and permeation testing work.

Wales & West Utilities (WWU) is undertaking a project to develop a thorough understanding of the technical and economic requirements for integrating hydrogen refuelling stations (HRS) into the existing gas network. The main aim is to enable the supply of ‘on-spec’ hydrogen for fuel cell electric vehicles (FCEVs) and hydrogen internal combustion engines (HICEs) from the heat-grade hydrogen currently delivered by the network. This involves analysing the types of contaminants present in grid hydrogen, pinpointing the purification technologies needed, and assessing the infrastructure requirements for compression, chilling, and storage to deliver hydrogen at the target pressures of 350 and 700 bar.

Develop credible and independently modelled pathways, to test the economic case of developing a H₂ Backbone and prepare NGT for dialogue with NESO, DESNZ, HMT and a wider group of stakeholders.

IGEM have received requests from operators to update the hydrogen TD1 / TD13 supplements to take account of outputs from research projects. The project will review and assess the updates required based on findings from completed hydrogen research projects. This will support the repurposing of existing pipelines and installations from Natural Gas to hydrogen and Natural Gas/hydrogen blends, with input and support from users/stakeholders and formal approval by IGEM.

The project will also develop a methodology for fracture and fatigue assessments for existing Natural Gas pipelines to be repurposed to hydrogen service. This methodology will assess the impact of blends of hydrogen up to and including 100% hydrogen to determine whether pipeline derating and/or deblending is required. The requirements for the application of this specification should be included in the updates to the IGEM/TD/1 and IGEM/TD/13 hydrogen supplements.

Phase 1 of the project compiled a list of oils and greases considered to be gas-facing on the NTS, along with identifying functional and material property requirements of these products. Proposed standards and testing methodologies were also outlined to inform the next phase of the project. In Phase 2, the project will proceed with additional required activities to ensure the safe utilisation of NTS oils/greases in a hydrogen pressurised environment. These activities include laboratory testing for lubricants and functional testing for sealants to assess degradation and performance of these products in hydrogen. Subsequently, requirements for in-service monitoring will be identified.

Existing defect assessments and repair methodologies are aligned with the P/11, P/20 and PM/DAM1 management procedures and are adopted to inspect, assess and repair the pipelines for defects and take suitable measures to reduce them. However, the scope and applicability of these assessment and repair methodologies in the presence of gaseous phase carbon dioxide remain uncertain. The key challenges which the project aims to address are:

• Will existing repair techniques such as epoxy shell, welded shells, composite wraps, gouge dressing etc. be suitable for transmission of gaseous phase carbon dioxide?
• What are the different defects we may encounter or consider hazardous in the presence of carbon dioxide? What are the impacts of carbon dioxide on each defect type? And how much does water/corrosion exacerbate this?
• Have the mechanisms of failure for each defect type changed after introducing carbon dioxide?
• Can we implement the assessment and repair methodologies safely? Are the techniques safe and suitable for the pipeline operations and maintenance teams?

The project seeks to answer the above in addition to understanding the types and extent of repairs across the NTS and review the impact of carbon dioxide on the effectiveness of these inspection, assessment and mitigation technologies.

The LISTEN (Local Insights Supporting Transparent Energy Networks) project aims to create a scalable, data-led approach to understanding and building social consent for the energy transition. LISTEN integrates AI-driven tools, place-based engagement, and co-designed dashboards to help energy networks plan with communities, not just for them.

The platform brings together four core elements:

• Regional Dashboards: Visualising insights by geography, topic, and demographics to inform planning and engagement strategies.
• Multi-Source Data Capture: Synthesising local news, social media, planning documents, and community events for a holistic view of local feeling.
• Voice-Enabled Surveys: Capturing authentic community sentiment in people’s own words, with AI sentiment analysis assessing tone, confidence, and emotion.
• Tailored Recommendations: Providing SGN and partners with actionable insights and engagement strategies aligned with Ofgem’s fairness and consumer-centric priorities.

This project investigates the technical and economic feasibility of converting non-domestic buildings from natural gas to low carbon energy sources, specifically hydrogen and electricity. It aims to address the significant evidence gap around the conversion of commercial and institutional buildings that are currently supplied by the GB gas distribution networks. The study will assess a wide range of building archetypes, including care homes, schools, hospitality venues, and light industrial sites, using a combination of literature review, site surveys, detailed system designs, and technoeconomic modelling. The outputs will inform future energy policy, support infrastructure planning, and help ensure safe and cost-effective deployment of low carbon technologies in non-domestic settings.

This project will develop network and/or entry site solutions that will enable biomethane supply to meet the swings in demand through the year.