Net zero and the energy system transition

This project will undertake testing on technology for distributed production of low carbon hydrogen from natural gas biogas or other short chain hydrocarbons from waste. Which uses 90% less electricity than electrolysis of water and with 68% lower total energy costs.

The project will support early movers and convert gas from our network into a low carbon hydrogen solution. The compact and modular deployment of the technology enables hydrogen production systems to be installed directly at the energy user's site. These systems convert grid-supplied natural gas to hydrogen on demand eliminating the need for additional infrastructure or on-site hydrogen storage and leaves the rest of the network unaffected

As the UK attempts to decarbonise residential heat to meet net zero by 2050 electric heat pumps along with heat networks are expected to play a key role. However it is generally accepted that no one technology will be able to meet the needs of all households. If we are to deliver affordable low- carbon heating in the residential sector we shall need as wide a range of technology options as possible to overcome the economic and technical challenges facing every customer.

Project GaIN (Gathering Insights) will explore alternatives to heat pumps and heat networks which can utilise the robust gas network and benefit from its current upgrade programme supporting the aims of DESNZ’s decarbonisation of heat roadmap. The project will discover and assess additional technology options where alternative solutions might be more costly or difficult to deliver; this will include LAEP system benefits as well as localised CAPEX and OPEX costs.

The Gas Network Evolution Simulator (GNES) is an innovative project aimed at optimising the transition away from natural gas by using advanced Agent Based Modelling (ABM). GNES simulates the complex interactions between stakeholders such as Gas Distribution Networks (GDNs) Electricity Networks consumers and policymakers. It analyses economic social and environmental impacts of gas network decommissioning and explores new infrastructure opportunities. By identifying challenges and benefits GNES supports the development of cost-effective equitable solutions that support vulnerable populations ensuring a smooth transition to low-carbon energy sources while minimising consumer disruption and maximising network efficiency.

This project will examine the suitability of existing Fire and Gas (F&G) detection and suppression systems for use with hydrogen blends of up to 20%. These systems comprise: fire detection fire suppression gas detection and associated control systems. They are found in compressor cabs and at network terminals.

Through CFD modelling three representative F&G systems will be individually assessed for compatibility with blends and will then be used as examples to make comments on the suitability of other F&G systems on the network. Where assets or control systems are not suitable this project will not design a new system but recommend where changes should be made and demonstrate how those changes safely manage risk – including cost estimation for upgrade or retrofit.

This project will help to provide assurance to UK Gas Distribution Network Operators (GDNOs) and wider industry on the safe design of domestic gas appliances in a future where hydrogen is being distributed in network pipelines. A risk to the normal safe operation of appliances under 100% hydrogen operation exists where a flammable hydrogen/air mixture is supplied to the appliance creating the potential for flashback to occur within the gas installation pipework. This work will provide assurance that domestic appliances designed to operate on 100% hydrogen are designed in a way which do not enable flashback to occur.

The project will also investigate the long-term feasibility of installing an auto-locking Emergency Control Valve (ECV) at the end of 100% hydrogen networks to ensure that any reinstatement of supply after a period of isolation can only be undertaken by a competent gas engineer.

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.

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.

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 project constitutes a UK-wide strategic assessment of the policy and regulatory frameworks governing biomethane production and grid injection with the objective of identifying how these frameworks can be updated to unlock growth. The review will examine the current policy landscape support mechanisms and regulatory arrangements affecting biomethane development including uncertainties associated with existing schemes and fragmented governance structures.

The Technical Blueprint Project forms a critical enabling phase of Cadent’s Hydrogen Blending Implementation Programme. Its purpose is to translate existing high level hydrogen blending evidence into a detailed network specific asset level and operationally deliverable blueprint that defines what is required for the gas network to safely and compliantly accommodate hydrogen blends of up to 20% by volume once regulatory approval is granted.

While previous industry projects have established that hydrogen blending is feasible in principle many technical operational and cost decisions remain at an asset process system and people level. These gaps currently prevent informed investment decisions and cannot be addressed through business‑as‑usual activity. This project addresses that gap by undertaking structured technical validation impact refinement and mitigation definition across Cadent’s network with a particular focus on the North West and East Midlands as pilot regions.

The project will coordinate specialist technical suppliers to validate prior hydrogen impact assessments against the most up‑to‑date safety evidence identify and close remaining evidence gaps and determine clear final mitigation positions for all affected assets and operational activities. Outputs will be consolidated into a single integrated technical blueprint providing a sequenced and costed set of actions required to achieve “blend readiness”. Areas confirmed as having no impact will also be explicitly documented to avoid unnecessary future intervention and cost.

The Technical Blueprint will provide Cadent and wider GB networks with a robust evidence‑based foundation to support future regulatory submissions funding reopeners and implementation planning. Learning generated will be transferable across gas distribution networks supporting a coordinated cost‑effective and safe transition toward hydrogen blending while reducing long‑term consumer risk and avoiding premature or inefficient investment.

This project will develop understanding of how the GB gas network would operate in a system aligned to Future Energy Scenarios (FES) 2025 scenarios for 2050.

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.

The Hydrogen Condition and Test Effect (HCATE) project will investigate the effect of moisture on fatigue crack growth rate (FCGR) and the influence of loading rate on fracture toughness of API 5L X52 pipeline steel in hydrogen environments. The project will generate experimental data to improve understanding of how environmental conditions influence crack propagation behaviour and fracture resistance in pipeline steels.

Laboratory-scale testing will be conducted on representative pipeline material in air and pressurised gaseous hydrogen environments including hydrogen saturated with water and hydrogen containing trace oxygen. These conditions are intended to simulate environmental conditions that may be present within pipeline systems.

Complementary fracture toughness testing will also be conducted at different loading rates to evaluate the influence of loading conditions on fracture resistance. The results will support the development of improved pipeline integrity assessments and contribute to the evidence base required for the safe repurposing of the UK Local Transmission System (LTS) for hydrogen transport.

This project constitutes a focused feasibility assessment of local biomethane market models with the objective of determining how decentralised commercial arrangements can enable increased participation from small-scale and community anaerobic digestion (AD) producers. The study will examine commercial structures regulatory considerations and stakeholder readiness associated with enabling localised trading of green gas through existing distribution networks. It will assess the interaction between market design connection approaches and consumer engagement to identify viable pathways for implementation and scale-up.

This project will help Cadent to understand considerations for a Net Zero Multi-Vector at a town scale to inform future activity on preparation for repurposing. An area will be chosen which is representative of different networks housing stock and demographics which will require different approaches and engagement.

The transition from natural gas to hydrogen introduces new material challenges within the context of the GB gas network. One critical concern is hydrogen embrittlement particularly in 17-4 Precipitation Hardened (PH) Stainless Steel commonly used in axial flow regulators and other key gas network components like valve stems. Hydrogen embrittlement can significantly reduce ductility fatigue life and fracture toughness potentially leading to component failure. While research exists much of it focuses on extreme conditions (e.g. high pressures and rapid temperature cycling) that do not reflect typical operational environments in the GB gas network.

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.

NIA_NGN_346 demonstrated that in a 100% hydrogen conversion scenario hazardous areas of some above ground installations (AGIs) on the network would extend far beyond their current site boundaries. The Hazardous Area Impact Mitigation (HAIM) work programme was set up to investigate these findings and develop potential mitigations. Results highlighted discrepancies between the calculated values from the IGEM/SR/25 hydrogen supplement and empirical test measurements as well as revealed the compound impact of rounding on calculated hazardous zones.

HAIM 3 will propose two methods to reduce the specified zones from AGIs based on the evidence to date:

• Refine the IGEM/SR/25 supplement based on evidence from the HAIM results.
• Use the knowledge gained during the HAIM works to adapt AGI vents and sites to reduce plume sizes and hence exclusion zones. This is independent of any changes to IGEM/SR/25 and can be applied in parallel.

Both methods independently act to reduce the specified zones surrounding vent pipes in AGIs.

Additional evidence gaps around hydrogen/Natural Gas blends up to 20% will be examined by replicating the phase 2 workshop tests for blends. During the project additional opportunities will be sought to collaborate and share knowledge with any third-party studies of large-scale gas releases.

Knapton Hydrogen Storage for Hydrogen to Power Discovery phase will investigate options for medium and large-scale storage of hydrogen to enable Centrica’s H2P project at Knapton via energy asset re-purposing the flexible use of hydrogen in the region for industrial decarbonisation and infrastructure scale up opportunities to provide resilience for the proposed East Coast Hydrogen core H2 network in North Yorkshire.

Analysis of the distribution networks undertaken in the H2 Caledonia and H2 Connect projects has identified sectorisation isolation as the optimal approach for conversion. Sectorisation isolation allows for a sector-by-sector approach ensuring the gradual conversion of existing Natural Gas connections over to hydrogen or managing the disconnection process should customers opt for alternative heating solutions. This project will aim to develop an understanding of the technical and financial feasibility of a Flexible Gas Transition Plant (FGTP) through primary project outputs such as: outline of design options development of a list of transition use cases a cost benefit analysis (CBA) for each transition scenario and a roadmap for future phases including prototype design and trials.

This project focuses on ensuring accurate volume conversion within gas metering processes as hydrogen is blended into the natural gas network across Great Britain. Accurate measurement is essential for fair billing and maintaining customer trust during the energy transition. The project will study real world metering installations assess potential errors caused by hydrogen blending and develop practical mitigation strategies. Findings will inform updates to industry guidance (IGEM/GM/5) supporting regulatory compliance and operational integrity.

The LTS Futures project aims to understand how the local transmission system (LTS) could be repurposed from Natural Gas to hydrogen. The project encompasses several elements which will feed into a blueprint methodology for repurposing the LTS to hydrogen. During one of the work elements LTS Futures conducted full-scale testing of pipeline defects and small-bore connections exposed to hydrogen. Testing was conducted until failure to provide information for hydrogen pipeline design standards and operational procedures. This project will undertake further detailed analysis of the fracture surfaces to provide a visual confirmation of hydrogen diffusion into the pipeline microstructure and if this contributed to failure.

The UK gas networks are undergoing a major transition to support the integration of green gases including biomethane and hydrogen. A significant challenge is the inability of the current design modelling. Cadent’s current modelling relies on outdated assumptions and lacks the granular real-time demand insight needed for modern decarbonising gas networks. Existing tools cannot capture intra-day demand variability below-7-bar network complexity or the growing impact of biomethane injections—creating risks in planning operational decisions and reinforcement strategy.

RTN addresses these challenges by delivering accurate weather-adjusted consumer-level demand modelling and integrated analysis across pressure tiers. This enhances forecasting improves biomethane integration and strengthens model validation and operational control. In the future state RTN provides Cadent with a modern data-rich and automated modelling capability that reduces unnecessary reinforcement improves customer outcomes supports the energy transition and lays the foundation for potential future use in peak-demand modelling and regulatory engagement.

This programme is leveraging the data and learning from historic projects to develop a range of novel network modelling tools that will enable biogas designs to be informed consumer focused and optimised for localised conditions and demands.

Decarbonisation of UK transport and the related Zero Emission Vehicle (ZEV) mandate requires companies to transition their commercial vehicle fleets to Battery Electric Vehicles (BEV) or alternative new emerging technologies (e.g. FCEC). As an operational utility network with responsibility for public safety WWU’s fleet undergoes a more challenging and varied range of duty cycles than most commercial fleets includes vehicles that are required to provide on-site power and must be capable of meeting WWU’s statutory duty to respond quickly to Public Reported Escapes.

Within this challenging operational context WWU must deliver a fleet transition at the lowest feasible cost to assure value for money for our customers. This is further complicated by the need to plan the fleet transition while the associated technological and policy landscape continues to evolve in parallel. Although the learnings generated from the project will be specific to WWU’s fleet as a case study they will be applicable to any networks with an operational fleet.

To assure a cost-effective transition and derisk future operations WWU require a Total Cost of Operation (TCO) model. This will be specifically targeted at our particular operational context capable of assessing the costs and capabilities of a range of ZEV options and crucially must be easy for staff to adopt for internal use and update in the future as new data and/or technologies become available.

The purpose of this project is to provide WWU with a TCO model that addresses our specific operational requirements ensuring that plans and investment decisions will be grounded in real-world technology assessments and our operational fleet data.