Future Energy Networks

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.

As part of National Gas’s Three Molecule strategy, the technical evidence for the transportation of hydrogen and carbon dioxide through the National Transmission system is being gathered through the HyNTS and CO₂ programmes. This technical evidence will feed into the updates of NGT’s suite of policies and procedures which are used to demonstrate compliance with the Gas Safety (Management) Regulations (GSMR), Pipeline Safety Regulations (PSR) and Pressure System Safety Regulations (PSSR).

This project will develop the approaches to compliance with regulations for hydrogen, hydrogen blends and CO₂, considering both new build and repurposed assets. The project will also define how the NTS Safety Case of the future will look, including modular design and digitalisation to streamline access to information.

Existing defect assessments and repair methodologies are aligned with the T/PM/P/11 and T/PM/P/20 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 the repair techniques in the presence of high-pressure hydrogen remain uncertain. The key questions which form an outline of the project are:

1. What are the different types of defects, we may encounter or consider injurious in the presence of hydrogen?
2. What is the impact of hydrogen on each defect type? Have the mechanisms of failure changed for each defect type after hydrogen-natural gas blending?
3. Will the existing repair techniques be applicable under transmission of high-pressure hydrogen and hydrogen-natural gas blends?
4. Can we implement the defect assessment, inspection 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 assess the impact of hydrogen on the effectiveness of these inspection, assessment and mitigation technologies.