Net zero and the energy system transition

The UK Government has identified Carbon Capture Utilisation and Storage (CCUS) as a critical enabler of industrial decarbonisation committing £20 billion to early deployment and targeting 20-30 MtCO₂ stored annually by 2030. Much of the UK’s industrial emissions are geographically concentrated opening the door to targeted CCUS clusters that can deliver outsized impact. GDNs are well positioned to play a meaningful role in this emerging ecosystem.

In Carbon Networks Phase 1 Blunomy assessed the strategic fit between CCUS and the GDN business model. The study identified a range of potential roles including local CO₂ collection participation in transport and storage networks and support for blue hydrogen and CO₂ utilisation initiatives – and it highlighted the importance of early positioning to shape regulatory and commercial pathways.

Phase 2 aims to build on this foundation and move from conceptual framing to actionable insight. Blunomy in the next stage will explore specific industrial opportunities within SGN’s and WWU’s footprint engage with project developers and clusters and outline potential pilot activities. Alongside this the work will assess how CCUS participation aligns with SGN’s broader priorities and the implications for regulatory engagement and investment planning.

High pressure steel pipelines are essential in enabling a safe natural gas transportation network an overly engineered solution tried and tested over several decades proving the NTS to be a robust nationwide asset. The National Transmission System is used to flow gas every day to keep the lights on and our homes heated by connecting large scale industry cities and towns where the network is dynamic allowing for flexibility and adaptability to various flow demand scenarios. This is done so by utilising over 5000 miles of varying grades and differing sizes of pipelines where the gas can flow build line pack for high energy demand areas and provide a mass energy storage solution.

The NTS is used to limit gas loss manage flow direction facilitate maintenance repair modification testing and commissioning to enable safe and effective start-up and shutdown of our pipelines. We now must further evidence pipeline steel material integrity when subjected to high pressure hydrogen gas this can be done by expanding upon the existing fatigue rig standalone testing at DNV Spadeadam.

Although some pipelines materials that we use today have seen blends and 100% hydrogen within the HYNTS Phase 1 test facility what we have not done is post hydrogen fatigue cycling non destructive testing of materials that have been subject to prolonged high pressure hydrogen. One of the welds that make up the fatigue rig has a known weld defect within it NGT aims to have the welds and the weld defect analysed through various methods of testing such as magnetic particle inspection followed by if necessary standard ultrasonic testing.

In 2022 small scale mechanical characteristic tests were conducted to characterise the mechanical properties of the materials used within the construction of the fatigue rig this testing commenced outputting a standard mechanical property data set the new end of test data post hydrogen exposure will be compared to the original data set from 2022 at the end of fatigue cycling. Testing will establish the effect of trapped hydrogen on ‘standard’ mechanical properties measured To facilitate this DNV will remove all girth welds selected seam welds and fitting welds and store them at low temperature to mitigate loss of hydrogen from within the trap sites..

A technical note will be prepared comparing the results of the weld inspections (internal and external inspections). The note will be used to confirm defect removal for metallographic examination.

A technical report will be prepared summarising the macro and microscopic examinations undertaken confirming defect size (to that reported by UT) and whether the defect was an original feature else created due to the pressure cycle duty of the test vessel and the hydrogen environment.

This project concerns the research into welding residual stress values and the effect that they have on the overall pipework repurposing assessment route described in relevant hydrogen standards. Currently overly conservative values need to be applied for welding residual stresses in any repurposing assessment. This project aims to build evidence on actual and modelled residual stresses seen within the pipelines industries with a focus on natural gas pipelines. As the welding residual stress is a critical aspect of the fracture mechanics assessment any improvements which can be gained would have an overall positive impact on the assessment results.

This project aims to develop a robust evidence-based framework to support the introduction of standardised separation distance tables for 100% hydrogen similar in format and function to those in IGEM/TD/3 for natural gas and hydrogen blends. This will address a gap in current standards for hydrogen. The Institute of Gas Engineers and Managers (IGEM) are providing resource to support the project and to update any necessary standards.

The key subject of HIRSA stage 2 projects is to understand if using hydrogen in the gas network will result in an increased likelihood of ignition from static discharge generated by particulates in flowing gas. Building on stage 2A stage 2B will provide further experimental testing aimed at determining the absolute difference in electrostatic charge generated identify whether any external factors impact one gas more than the other and to control the factors affecting generation of the charge. The outputs of this work should provide the industry with a better understanding of the potential change in ignition risk when switching from Natural Gas to hydrogen and will also highlight relevant mitigations to manage this risk.

GNES (Gas Network Evolution Simulator) uses Agent Based Modelling to simulate how people policies and infrastructure interact as the UK transitions away from natural gas. By reflecting real-world behaviours and decisions it helps energy networks policymakers and communities explore fair cost-effective pathways to decarbonisation. GNES reveals how transition choices impact different households and regions ensuring no one is left behind. Developed by the Centre for Energy Equality with industry and public partners GNES supports a whole-system approach to planning a just and resilient energy future that works for everyone not just those able to move first.

The work will give relevant stakeholders a better understanding of the value of biomethane-powered hybrid heating systems as an important input into the debate over the UK’s future domestic heating landscape and the role biomethane can play in this system. This is a Green Gas Taskforce-related project being led by Cadent.