Net zero and the energy system transition

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.

UK’s Net Zero Emissions Target and the Role of Hydrogen: The UK has committed to a legally binding net zero emissions target by 2050. Achieving this target necessitates the integration of hydrogen particularly in hard-to-decarbonize industrial applications and peaking power generation. The recent publication of the Climate Change Committee’s Seventh Carbon Budget highlights hydrogen’s significant role within the electricity supply sector. Hydrogen is identified as a crucial source of long-term storable energy that can be dispatched as needed and as a feedstock for synthetic fuels. For hydrogen to fully contribute to a future hydrogen system its production storage and transportation must be considered collectively.

East Coast Hydrogen (ECH) Project: In recent years Cadent in partnership with National Gas and Northern Gas Networks (NGN) has developed the East Coast Hydrogen (ECH) Project. The ECH project aims to decarbonize primarily industry and power sectors. As part of this initiative Cadent has developed the East Midlands Hydrogen Pipeline (EMHP) which aims to connect hydrogen production at Uniper’s Ratcliffe on Soar site to major industrial and power off-takers in the East Midlands. The project seeks to transport hydrogen to major population centres including Nottingham Leicester Melton Mowbray Derby and Burton upon Trent. During the development of the EMHP it became evident that hydrogen storage plays a critical role in establishing a resilient and efficient hydrogen system. Consequently a consortium was formed to explore the feasibility of storage leading to the East Midlands Storage Project (EMSTOR).

Discovery Phase of EMSTOR: During the Discovery Phase EMSTOR evaluated various technologies for large-scale hydrogen storage in the East Midlands. The technologies considered included lined rock caverns lined rock shafts silos and geological storage options such as aquifers and disused hydrocarbon fields. After comparing these technologies against several technical parameters including Technology Readiness Level (TRL) cost size and location relative to pipelines it was determined that hydrogen storage in geological fields particularly disused hydrocarbon fields is the most viable option. Therefore disused hydrocarbon fields in geological formations were selected for further consideration in the Alpha Phase.

Alpha Phase Consortium: To execute the Alpha Phase a consortium led by Cadent and including Star Energy Ltd Centrica Energy Storage National Grid British Geological Society University of Edinburgh and Uniper was established. This consortium will focus on advancing the feasibility and implementation of hydrogen storage in disused hydrocarbon fields.

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.

In order to support UK ambitions for hydrogen blending and the development of a hydrogen economy National Gas will need to install new gas chromatographs with the capability to measure hydrogen up to 20% in a natural gas blend. At present hydrogen is not measured anywhere on the National Transmission System (NTS) and therefore there are no proven in-use devices and limited experience within the company to allow effective decision making in deploying these assets in the move towards net zero.

In order to make informed decisions ahead of chromatograph fleet upgrade and to allow for a wide selection of reliable device choices when it comes to that upgrade National Gas require the testing of available devices to analyse their performance and thus suitability for NTS installation. This project will employ a trusted testing house to obtain (through loaning) blend-ready chromatographs from suppliers and then to rigorously examine the performance of those devices. These devices could be tested at the testing house’s site or at the instrument vendor’s site.

This project will deliver a series of reports and presentations which reflect the need to minimise disruption during any conversion taking into account customer needs and the wider supply chain not just the needs of the GDN.

Clean Power 2030 (CP2030) aims for a fully decarbonised electricity system using unabated gas only as backup. This introduces an important challenge: how can the gas transmission network remain viable and deliver flexibility during extreme demand events despite not being utilised most of the time? This project aims to understand how to sustain the gas network technically and economically in a low average high peak demand future focusing on the interaction between gas and electricity systems.

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.