Future Energy Networks

Laboratory and full-scale testing have demonstrated that hydrogen gas affects the fracture performance of pipeline steel welds. To avoid severe knockdown factors stipulated by existing hydrogen pipeline codes, mechanical property data from welds tested in high-pressure gaseous hydrogen is required to enable optimised operation of the NTS in hydrogen.

National Gas Transmission have conducted a series of fracture toughness and fatigue crack growth rate tests on a wide selection of pipeline steels and welds representative of those used on the National Transmission System (NTS). A thorough review of the welds tested and how these compare to the wider population of welds in service on the NTS is required to provide further confidence to use this data in pipeline repurposing assessments and for new build design.

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.

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.

NGN currently operate a Lotus Notes application with a bespoke electronic Logbook system to capture all of the activity with day and planned ahead that occurs within our gas control centre. This system has been in operation since 1997 and has proven to be a highly reliable and flexible tool to manage planned works, faults, general site activity and wider issues.

The current technology is outdated and contains years’ worth of data causing it to be slow. There are no links between Lotus notes and other vital control room applications (SCADA etc.). Raising faults becomes a tedious task and the Logbook and other in-apps are not user friendly. There are no updates available to improve the existing system.

The current system needs to be replaced but to achieve that we need a full exploration of where technology can deliver to our requirements, and to fully explore the impact of net zero and what new functionality may be required to manage the transition to net zero.

This is an early stage feasibility project to understand all of the challenges, opportunities and risks that UK GDNs face with their systems, in order to help facilitate the transition to net zero energy systems.

The MASiP Phase 3 project aims to develop, test, and qualify a new pipeline system (MASiP) as a safe and cost-effective alternative to traditional steel pipelines for pipelines operating above 7 bar, capable of transporting natural gas, biogas, and up to 100% hydrogen. Building on Phases 1 and 2, this phase focuses on the technical assessment of tight radius bends, tees, and damage repair, as well as the integration of live monitoring systems in a prototype operational environment. Comprehensive validation will include connectors, coatings, repair systems, hot-tapping solutions, ground movement tolerance, durability, and design life testing. All testing will be carried out in accordance with IGEM, API, and ASME standards, supported by statistical and independently witnessed trials to generate robust qualification data for industry adoption. The key deliverable is a validated, deployable hydrogen-ready pipeline system that is safe, compliant, and cost-effective, offering potential cost savings of up to 50% compared with steel. The project outcomes will support the UK’s RIIO-GD2 strategy and 2050 net-zero targets by enabling hydrogen-ready infrastructure, improving monitoring, installation efficiency, and long-term reliability, while also providing the evidence base required for regulatory, policy, and industry acceptance of alternative pipeline materials.

This project will build upon previous work to inform decisions relating to the repurposing of National Transmission System pipelines for 100% hydrogen and hydrogen-natural gas blends. New input data will be generated and collated, the assessment methodology will be refined and an alternative assessment method, probabilistic, will be utilised and the resulting network impact will be considered.

This project will generate the following benefits:

• More accurate assessment of the capability of the NTS to transport 100% hydrogen and hydrogen-natural gas blends.
• Data on the impact of low percentage blend hydrogen on pipeline materials.
• Standardised document for Engineering Critical Assessments (ECA) of hydrogen and hydrogen-natural gas blend pipelines and pipework.

Greater understanding on the effect of hydrogen on the design and operation of pipeline systems.

This project aims to explore the impact of hydrogen blends (in natural gas), 100% hydrogen and carbon dioxide on contaminants (arisings) likely to be found in gas transmission pipelines (e.g. Naturally Occurring Radioactive Materials (NORMs), dusts, mill scale, welding slag, glycols, water, BTEX, methanol, heavy metals, sulphur compounds, pyrophorics as well as rotating machinery lube/seal oils and valve sealants etc).

The project will aim to understand the current composition and characteristics of any contaminants, the impact of hydrogen and carbon dioxide on the behaviour/composition/presence of contaminants, establish how long methane related contaminants will persist on the network (for repurposed pipelines), the potential for contaminants to cause pipeline gas to go ‘off-spec’ and the implications of contaminant interactions on National Transmission System (NTS) operation/integrity.

National Gas are investigating the use of the National Transmission System to transport hydrogen and hydrogen blends. To support this, research and testing is required to understand the risks of high pressure hydrogen transmission, including ignition. This project will identify, for 100% hydrogen and blends of hydrogen up to 20%, the sources of ignition including how the distance of ignition sources affects the likelihood of ignition. It will also investigate the frequency and the different types of ignition events e.g. jet fires. Lastly, it will look at the probability of ignition on sites and in pipework.