Publications

Hydrogen vehicles encompassing fuel cell electric vehicles (FCEVs) are pivotal within the UK’s energy landscape as it pursues the goal of net-zero emissions by 2050. By markedly diminishing dependence on fossil fuels FCEVs including hydrogen vehicles wield substantial influence in shaping the circular economy (CE). Their impact extends to optimizing resource utilization enabling zero-emission mobility facilitating the integration of renewable energy sources supplying adaptable energy storage solutions and interconnecting diverse sectors. The widespread adoption of hydrogen vehicles accelerates the UK’s transformative journey towards a sustainable CE. However to fully harness the benefits of this transition a robust investigation and implementation of safety measures concerning hydrogen vehicle (HV) use are indispensable. Therefore this study takes a holistic approach integrating quantitative risk assessment (QRA) and an adaptive decision-making trial and evaluation laboratory (DEMATEL) framework as pragmatic instruments. These methodologies ensure both the secure deployment and operational excellence of HVs. The findings underscore that the root causes of HV failures encompass extreme environments material defects fuel cell damage delivery system impairment and storage system deterioration. Furthermore critical driving factors for effective safety intervention revolve around cultivating a safety culture robust education/training and sound maintenance scheduling. Addressing these factors is pivotal for creating an environment conducive to mitigating safety and risk concerns. Given the intricacies of conducting comprehensive hydrogen QRAs due to the absence of specific reliability data this study dedicates attention to rectifying this gap. A sensitivity analysis encompassing a range of values is meticulously conducted to affirm the strength and reliability of our approach. This robust analysis yields precise dependable outcomes. Consequently decision-makers are equipped to discern pivotal underlying factors precipitating potential HV failures. With this discernment they can tailor safety interventions that lay the groundwork for sustainable resilient and secure HV operations. Our study navigates the intersection of HVs safety and sustainability amplifying their importance within the CE paradigm. Using the careful amalgamation of QRA and DEMATEL methodologies we chart a course towards empowering decision-makers with the insights to steer the hydrogen vehicle domain to safer horizons while ushering in an era of transformative eco-conscious mobility.

The H21 Phase 2 research will provide vital evidence both towards the hydrogen village trial and potential town scale pilots and to the Government which is aiming to make a decision about the use of hydrogen for home heating by 2026.

The key objectives of the H21 Phase 2 NIC project were to further develop the evidence base supporting conversion of the natural gas distribution network to 100% hydrogen. The key principles of H21 NIC Phase 2 were to:

→ Confirm how we can manage and operate the network safely through an appraisal of existing network equipment procedures and network modelling tools.

→ Validate network operations on a purpose-built below 7 barg network as well as an existing unoccupied buried network and provide a platform to publicise and demonstrate a hydrogen network in action.

→ Develop a combined distribution network and downstream Quantitative Risk Assessment (QRA) for 100% hydrogen by further developing the work undertaken on the H21 Phase 1 QRA and the Hy4Heat ‘downstream of ECV’ QRA.

→ Continue to understand how consumers could be engaged with ahead of a conversion. This programme was split into four phases detailed below:

→ Phase 2a – Appraisal of Network 0-7 bar Operations

→ Phase 2b – Unoccupied Network Trials

→ Phase 2c – Combined QRA

→ Phase 2d – Social Sciences

The project with the support of the HSE’s Science & Research Centre (HSE S&RC) and DNV successfully undertook a programme of work to review the NGN below 7 barg network operating procedures. The project implemented testing and demonstrations on the Phase 2a Microgrid at DNV Spadeadam and Phase 2b Unoccupied Trial site in South Bank on a repurposed NGN network to provide and demonstrate the supporting evidence for the required changes to procedures. Details of the outputs of the HSE S&RC procedure review and the evidence collected by DNV from the testing and demonstration projects is provided in detail in this technical summary report.

Due to the differences in gas characteristics between hydrogen and natural gas changes will be required to some of the operational and maintenance procedures the evidence of which is provided in this report. The Gas Distribution Networks (GDNs) will need to review the findings from this project when implementing the required changes to their operational and maintenance procedures.

Proton exchange membrane fuel cells (PEMFCs) are attracting attention for their green energy-saving and high-efficiency advantages becoming one of the future development trends of renewable energy utilization. However there are still deficiencies in the gas supply system control strategy that plays a crucial role in PEMFCs which limits the rapid development and application of PEMFCs. This paper provides a comprehensive and in-depth review of the PEMFC air delivery system (ADS) and hydrogen delivery system (HDS) operations. For the ADS the advantages and disadvantages of the oxygen excess ratio (OER) oxygen pressure and their decoupling control strategies are systematically described by the following three aspects: single control hybrid control and intelligent algorithm control. Additionally the optimization strategies of the flow field or flow channel for oxygen supply speeds and distribution uniformity are compared and analyzed. For the HDS a systematic review of hydrogen recirculation control strategies purge strategies and hydrogen flow control strategies is conducted. These strategies contribute a lot to improving hydrogen utilization rates. Furthermore hydrogen supply pressure is summarized from the aspects of hybrid control and intelligent algorithm control. It is hoped to provide guidance or a reference for research on the HDS as well as the ADS control strategy and optimization strategy

Public transport plays a prominent role with respect to mitigating transport-related environmental effects by improving passenger transport efficiency and the quality of life in cities. Batteries and fuel cells are at the forefront of the technological shift to zero-emission powertrains. Within the scope of the German-funded project BIC H2 corresponding systems analysis research focuses on the market introduction of fuel cell–electric buses in the Rhine–Ruhr Metropolitan Region through 2035. This study presents the related methods and major outcomes of this techno-economic research which spans spatially-resolved hydrogen demand modeling of all relevant sectors to hydrogen refueling stations and upstream infrastructure modeling to scenario-based analyses. The latter builds upon an empirical study supporting the development of the Hydrogen Roadmap of the State of North Rhine–Westphalia (NRW). Our results show that the demand in NRW alone is expected to account for one third of total German hydrogen use. Hydrogen bus refueling could substantially support market introduction during its early phases. In the long term however hydrogen demand in industry is significantly higher compared to that in the transport sector. Furthermore spatial analysis identifies regions with pronounced hydrogen demands that could therefore be candidates for initial infrastructure investments. With the Cologne area showing the highest hydrogen demand levels such regions can offer particularly high infrastructure utilization e.g. for bus refueling. On the infrastructure side trailers for transporting gaseous hydrogen to refueling stations are the most favorable option through 2035. Pipelines would be the preferred solution soon after 2035 due to increased hydrogen demand. If effectively deployed converted natural gas pipelines would be the most cost-effective option even earlier.

In this paper we study the dispersion ignition and flame characteristics of blended jets of hydrogen and methane (as a proxy for natural gas) at near-atmospheric pressure for a fixed volumetric flow rate which mimics the scenario of a small-scale unintended leak. A reduction in flame height is observed with increasing hydrogen concentration. A laser is tightly focused to generate a spark with sufficient energy to ignite the fuel. The light-up boundary defined as the delineating location at which a spark ignites into a jet flame or extinguishes is determined as a contour. The light-up boundary increases in both width and length as the hydrogen content increases up to 75% hydrogen at which point the axial ignition boundary decreases slightly for pure hydrogen relative to 75% hydrogen. Ignition probability a key parameter regarding safety is computed at various axial locations and is also shown to be higher near the nozzle as well as non-zero at further downstream locations as the hydrogen content in the blend increases. Planar laser Raman scattering is used in separate experiments to determine the concentration of both fuel species. Mean fuel concentrations well below the lower flammability limit are both within the light-up boundary and have non-zero ignition probabilities.

For lignite intense regions such as the case of Western Macedonia (WM) the production and utilization of green hydrogen is one of the most viable ways to achieve near zero emissions in sectors like transport chemicals heat and energy production synthetic fuels etc. However the implementation of each technology that is available to a respective sector differs significantly in terms of readiness and the current installation scale of each technology. The goal of this study is the provision of a transition roadmap for a decarbonized future for the WM region through utilizing green hydrogen. The technologies which can take part in this transition are presented along with the implementation purpose of each technology and the reasonable extension that each technology could be adopted in the present context. The WM region’s limited capacity for green hydrogen production leads to certain integration scenarios with regards to the required hydrogen electrolyzer capacities and required power whereas an environmental assessment is also presented for each scenario.

About 95% of current hydrogen production uses technologies involving primary fossil resources. A minor part is synthesized by low-carbon and close-to-zero-carbon-footprint methods using RESs. The significant expansion of low-carbon hydrogen energy is considered to be a part of the “green transition” policies taking over in technologically leading countries. Projects of hydrogen synthesis from natural gas with carbon capture for subsequent export to European and Asian regions poor in natural resources are considered promising by fossil-rich countries. Quality changes in natural resource use and gas grids will include (1) previously developed scientific groundwork and production facilities for hydrogen energy to stimulate the use of existing natural gas grids for hydrogen energy transport projects; (2) existing infrastructure for gas filling stations in China and Russia to allow the expansion of hydrogen-fuel-cell vehicles (HFCVs) using typical “mini-plant” projects of hydrogen synthesis using methane conversion technology; (3) feasibility testing for different hydrogen synthesis plants at medium and large scales using fossil resources (primarily natural gas) water and atomic energy. The results of this study will help focus on the primary tasks for quality changes in natural resource and gas grid use. Investments made and planned in hydrogen energy are assessed.

Solid-state hydrogen storage technology has emerged as a disruptive solution to the “last mile” challenge in large-scale hydrogen energy applications garnering significant global research attention. This paper systematically reviews the Chinese research progress in solid-state hydrogen storage material systems thermodynamic mechanisms and system integration. It also quantitatively assesses the market potential of solid-state hydrogen storage across four major application scenarios: on-board hydrogen storage hydrogen refueling stations backup power supplies and power grid peak shaving. Furthermore it analyzes the bottlenecks and challenges in industrialization related to key materials testing standards and innovation platforms. While acknowledging that the cost and performance of solid-state hydrogen storage are not yet fully competitive the paper highlights its unique advantages of high safety energy density and potentially lower costs showing promise in new energy vehicles and distributed energy fields. Breakthroughs in new hydrogen storage materials like magnesium-based and vanadium-based materials coupled with improved standards specifications and innovation mechanisms are expected to propel solid-state hydrogen storage into a mainstream technology within 10–15 years with a market scale exceeding USD 14.3 billion. To accelerate the leapfrog development of China’s solid-state hydrogen storage industry increased investment in basic research focused efforts on key core technologies and streamlining the industry chain from materials to systems are recommended. This includes addressing challenges in passenger vehicles commercial vehicles and hydrogen refueling stations and building a collaborative innovation ecosystem involving government industry academia research finance and intermediary entities to support the achievement of carbon peak and neutrality goals and foster a clean low-carbon safe and efficient modern energy system.

The geological storage of hydrogen is a seasonal energy storage solution and the storage capacity of saline aquifers is most appropriately defined by quantifying the amount of hydrogen that can be injected and reproduced over a relevant time period. Cushion gas stored in the reservoir to support the production of the working gas is a CAPEX which should be reduced to decrease implementation cost for gas storage. The cushion gas to working gas ratio provides a sufficiently accurate reflection of the storage efficiency with higher ratios equating to larger initial investments. This paper investigates how technical measures such as well configurations and adjustments to the operational size and schedule can reduce this ratio and the outcomes can inform optimisation strategies for hydrogen storage operations. Using a simplified open saline aquifer reservoir model hydrogen storage is simulated with a single injection and production well. The results show that the injection process is more sensitive to technical measures than the production process; a shorter perforation and a smaller well diameter increases the required cushion gas for the injection process but has little impact on the production. If the storage operation capacity is expanded and the working gas volume increased the required cushion gas to working gas ratio increases for injection reducing the efficiency of the injection process. When the reservoir pressure has more time to equilibrate less cushion gas is required. It is shown that cushion gas plays an important role in storage operations and that the tested optimisation strategies impart only minor effects on the production process however there is significant need for careful optimisation of the injection process. It is suggested that the recoverable part of the cushion gas could be seen as a strategic gas reserve which can be produced during an energy crisis. In this scenario the recoverable cushion gas could be owned by the state and the upfront costs for gas storage to the operator would be reduced making the implementation of more gas storage and the onset of hydrogen storage more attractive to investors.

South Korea ranking ninth among the largest energy consumers and seventh in carbon dioxide emissions from 2016 to 2021 faces challenges in energy security and climate change mitigation. The primary challenge lies in transitioning from fossil fuel dependency to a more sustainable and diversified energy portfolio while meeting the growing energy demand for continued economic growth. This necessitates fostering innovation and investment in the green energy sector. This study examines the potential impact of green energy expansion (through integrating renewable energy and hydrogen production) and gas import reduction on South Korea’s economic growth using a system dynamics approach. The findings indicate that increasing investment in green energy can result in significant growth rates ranging from 7% to 35% between 2025 and 2040. Under the expansion renewable energy scenario (A) suggests steady but sustainable economic growth in the long term while the gas import reduction scenario (B) displays a potential for rapid economic growth in the short term with possible instability in the long term. The total production in Scenario B is USD 2.7 trillion in 2025 and will increase to USD 4.8 trillion by 2040. Scenario C which combines the effects of both Scenarios A and B results in consistently high economic growth rates over time and a substantial increase in total production by 2035–2040 from 20% to 46%. These findings are critical for policymakers in South Korea as they strive for sustainable economic growth and transition to renewable energy.