Publications

The Hydrogen Economy concept is being proposed as a means of reducing and eventually decarbonising the world’s energy use. It looks to hydrogen as being a replacement for methane (natural gas) and generally as a way of removing all fossil fuels from the energy supply. The concept however has at least four flaws as follows: (1) hydrogen has significantly different properties to methane; (2) hydrogen has properties that create significant hazards; (3) hydrogen has a very small initiation (activation) energy; and (4) liquid hydrogen cannot readily replace liquefied natural gas (LNG). Hydrogen’s hazards will prevent it from being accepted in a societal sense. To the question ‘Can the Hydrogen Economy concept be the solution to the future energy crisis?’ the answer is ‘no’. Hydrogen has and will have a role in world energy but that role will be limited to industry. For the future we need an advanced electric economy.

ITM Power is a leading electrolyser manufacturer and is a globally recognised expert in hydrogen technologies. In this episode Graham Cooley Chief Executive Officer at ITM Power and John Williams Head of Hydrogen Expertise Cluster at AFRY Management Consulting join us to discuss ITM’s recent announcements. This includes raising £250 million to scale up its electrolyser manufacturing capacity to 5GW per annum by 2024 and forming a partnership with Linde to halve electrolyser manufacturing costs within five years. The episode also explores the UK hydrogen strategy how blue hydrogen compares with green hydrogen the role of electrolysers in hydrogen production and providing flexibility to power grids.

The podcast can be found on their website.

The number of demonstration projects with fuel cell buses has been increasing worldwide. The goal of this paper is to analyse prospects and barriers for fuel cell buses focusing on their economic- technical- and environmental performance. Our results show that the prices of fuel cell buses although decreasing over time are still about 40% higher than those of diesel buses. With the looming ban of diesel vehicles and current limitations of battery electric vehicles fuel cell buses could become a viable alternative in the mid-to long-term. With the requirements for a better integration of renewable energy sources in the transport system interest in hydrogen is rising. Hydrogen produced from renewables used in fuel cell buses has the potential to save about 93% of CO2 emissions in comparison to diesel buses. Yet from environmental point-of-view it has to be ensured that hydrogen is produced from renewables. Currently the major barrier for a faster penetration of fuel cell buses are their high purchase prices which could be significantly reduced with the increasing number of buses through technological learning. The final conclusion is that a tougher transport policy framework is needed which fully reflects the environmental impact of different buses used.

The maritime transport and the port-logistic industry are key drivers of economic growth although they represent major contributors to climate change. In particular maritime port facilities are typically located near cities or residential areas thus having a significant direct environmental impact in terms of air and water quality as well as noise. The majority of the pollutant emissions in ports comes from cargo ships and from all the related ports activities carried out by road vehicles. Therefore a progressive reduction of the use of fossil fuels as a primary energy source for these vehicles and the promotion of cleaner powertrain alternatives is in order. The present study deals with the design of a new propulsion system for a heavy-duty vehicle for port applications. Specifically this work aims at laying the foundations for the development of a benchmark industrial cargo–handling hydrogen-fueled vehicle to be used in real port operations. To this purpose an on-field measurement campaign has been conducted to analyze the duty cycle of a commercial Diesel-engine yard truck currently used for terminal ports operations. The vehicle dynamics has been numerically modeled and validated against the acquired data and the energy and power requirements for a plug-in fuel cell/battery hybrid powertrain replacing the Diesel powertrain on the same vehicle have been evaluated. Finally a preliminary design of the new powertrain and a rule-based energy management strategy have been proposed and the electric energy and hydrogen consumptions required to achieve the target driving range for roll-on and roll-off operations have been estimated. The results are promising showing that the hybrid electric vehicle is capable of achieving excellent energy performances by means of an efficient use of the fuel cell. An overall amount of roughly 12 kg of hydrogen is estimated to be required to accomplish the most demanding port operation and meet the target of 6 h of continuous operation. Also the vehicle powertrain ensures an adequate all-electric range which is between approximately 1 and 2 h depending on the specific port operation. Potentially the hydrogen-fueled yard truck is expected to lead to several benefits such as local zero emissions powertrain noise elimination reduction of the vehicle maintenance costs improving of the energy management and increasing of operational efficiency.

The holistic green energy transition of non-interconnected islands faces several challenges if all the energy sectors are included i.e. electricity heating/cooling and mobility. On the one hand the penetration of renewable energy systems (RES) is limited due to design restrictions with respect to the peak demand. On the other hand energy-intensive heating and mobility sectors pose significant challenges and may be difficult to electrify. The focus of this study is on implementing a hybrid Wind–PV system on the non-interconnected island of Anafi (Greece) that utilizes surplus renewable energy production for both building heating through heat pumps and hydrogen generation. This comprehensive study aims to achieve a holistic green transition by addressing all three main sectors—electricity heating and transportation. The produced hydrogen is utilized to address the energy needs of the mobility sector (H2 mobility) focusing primarily on public transportation vehicles (buses) and secondarily on private vehicles. The overall RES production was modeled to be 91724 MWh with a RES penetration of 84.68%. More than 40% of the produced electricity from RES was in the form of excess electricity that could be utilized for hydrogen generation. The modeled generated hydrogen was simulated to be more than 40 kg H2/day which could cover all four bus routes of the island and approximately 200 cars for moderate use i.e. traveled distances of less than 25 km/day for each vehicle.

While Afghanistan’s power sector is almost completely dependent on fossil fuels it still cannot meet the rising power demand of this country. Deploying a combination of renewable energy systems with hydrogen production as the excess energy storage mechanism could be a sustainable long-term approach for addressing some of the energy problems of Afghanistan. Since Badakhshan is known to have a higher average wind speed than any other Afghan province in this study a technical economic and carbon footprint assessment was performed to investigate the potential for wind power and hydrogen production in this province. Wind data of four stations in Badakhshan were used for technical assessment for three heights of 10 30 and 40 m using the Weibull probability distribution function. This technical assessment was expanded by estimating the energy pattern factor probability of wind speeds greater than 5 m/s wind power density annual power output and annual hydrogen output. This was followed by an economic assessment which involved computing the Leveled Cost Of Energy (LCOE) the Leveled Cost Of Hydrogen (LCOH) and the payback period and finally an carbon footprint assessment which involved estimating the consequent CO2 reduction in two scenarios. The assessments were performed for 22 turbines manufactured by reputable companies with capacities ranging from 600 kW to 2.3 MW. The results showed that the entire Badakhshan province and especially Qal’eh-ye Panjeh and Fayazabad have excellent potentials in terms of wind energy that can be harvested for wind power and hydrogen production. Also wind power generation in this province will be highly cost-effective as the produced electricity will cost about one-third of the price of electricity supplied by the government. For better evaluation the GIS maps of wind power and hydrogen outputs were prepared using the IDW method. These maps showed that the eastern and northeastern parts of Badakhshan province have higher wind power-hydrogen production potentials. The results of ranking the stations with SWARA-EDAS hybrid MCDM methods showed that Qal’eh-ye Panjeh station was the best location to produce hydrogen from wind energy.

Hydrogen technologies are promising candidates of new energy technologies for electric power load smoothing. However regardless of long-term public investment hydrogen economy has not been realized. In Japan the National Research and Development Institute of New Energy and Industrial Technology Development Organization (NEDO) a public research-funding agency has invested more than 200 billion yen in the technical development of hydrogen-related technologies. However hydrogen technologies such as fuel cell vehicles (FCVs) have not been disseminated yet. Continuous and strategic research and development (R&D) are needed but there is a lack of expertise in this field. In this study the transition of the budgetary allocations by NEDO were analyzed by classifying NEDO projects along the hydrogen supply chain and research stage. We found a different R&D focus in different periods. From 2004 to 2007 empirical research on fuel cells increased with the majority of research focusing on standardization. From 2008 to 2011 investment in basic research of fuel cells increased again the research for verification of fuel cells continued and no allocation for research on hydrogen production was confirmed. Thereafter the investment trend did not change until around 2013 when practical application of household fuel cells (ENE-FARM) started selling in 2009 in terms of hydrogen supply chain. Hydrogen economy requires a different hydrogen supply infrastructure that is an existing infrastructure of city gas for ENE-FARM and a dedicated infrastructure for FCVs (e.g. hydrogen stations). We discussed the possibility that structural inertia could prevent the transition to investing more in hydrogen infrastructure from hydrogen utilization technology. This work has significant implications for designing national research projects to realize hydrogen economy.

The development of clean hydrogen and photovoltaic (PV) systems is lagging behind the goals set in the Net Zero Emissions scenario of the International Energy Agency. For this reason efficient hydrogen production systems powered from renewable energy need to be deployed faster. This work presents an optimization procedure for a stand-alone fully PVpowered alkaline electrolysis system. The approach is based on the Particle Swarm Optimization algorithm to obtain the best configuration of the PV plant that powers the electrolyzer and its compressor. The best configuration is determined with one of three indicators: cost efficiency or wasted energy. The PV plant needs to be oversized 2.63 times with respect to the electrolyzer to obtain minimum cost while for high efficiency this number increases by 2%. Additionally the configuration that minimizes cost wasted energy or maximizes efficiency does not correspond to the configuration that maximizes the annual PV yield. Optimizing for cost results also leads to the best operation of the electrolyzer at partial loads than optimizing for efficiency or wasted energy.

The intermittent production of the renewable energy imposes the necessity to temporarily store it. Large amounts of exceeding electricity can be stored in geological strata in the form of hydrogen. The conversion of hydrogen to electricity and vice versa can be performed in electrolyzers and fuel elements by chemical methods. The nowadays technical solution accepted by the European industry consists of injecting small concentrations of hydrogen in the existing storages of natural gas. The progressive development of this technology will finally lead to the creation of underground storages of pure hydrogen. Due to the low viscosity and low density of hydrogen it is expected that the problem of an unstable displacement including viscous fingering and gravity overriding will be more pronounced. Additionally the injection of hydrogen in geological strata could encounter chemical reactivity induced by various species of microorganisms that consume hydrogen for their metabolism. One of the products of such reactions is methane produced from Sabatier reaction between H2 and CO2. Other hydrogenotrophic reactions could be caused by acetogenic archaea sulfate-reducing bacteria and iron-reducing bacteria. In the present paper a mathematical model is presented which is capable to reflect the coupled hydrodynamic and bio-chemical processes in UHS. The model has been numerically implemented by using the open source code DuMuX developed by the University of Stuttgart. The obtained bio-chemical version of DuMuX was used to model the evolution of a hypothetical underground storage of hydrogen. We have revealed that the behavior of an underground hydrogen storage is different than that of a natural gas storage. Both the hydrodynamic and the bio-chemical effects contribute to the different characteristics.

Autonomous Underwater Vehicles (AUVs) are vehicles that are primarily used to accomplish oceanographic research data collection and auxiliary offshore tasks. At the present time they are usually powered by lithium-ion secondary batteries which have insufficient specific energies. In order for this technology to achieve a mature state increased endurance is required. Fuel cell power systems have been identified as an effective means to achieve this endurance but no implementation in a commercial device has yet been realized. This paper summarizes the current state of development of the technology in this field of research. First the most adequate type of fuel cell for this application is discussed. The prototypes and design concepts of AUVs powered by fuel cells which have been developed in the last few years are described. Possible commercial and experimental fuel cell stack options are analyzed examining solutions adopted in the analogous aerial vehicle applications as well as the underwater ones to see if integration in an AUV is feasible. Current solutions in oxygen and hydrogen storage systems are overviewed and energy density is objectively compared between battery power systems and fuel cell power systems for AUVs. A couple of system configuration solutions are described including the necessary lithium-ion battery hybrid system. Finally some closing remarks on the future of this technology are given.

Fluid dispersion directly influences the transport mixing and efficiency of hydrogen storage in depleted gas reservoirs. Pore structure parameters such as pore size throat geometry and connectivity influence the complexity of flow pathways and the interplay between advective and diffusive transport mechanisms. Hence these factors are critical for predicting and controlling flow behavior in the reservoirs. Despite its importance the relationship between pore structure and dispersion remains poorly quantified particularly under elevated flow conditions. To address this gap this study employs pore network modeling (PNM) to investigate the influence of sandstone and carbonate structures on fluid flow properties at the micro-scale. Eleven rock samples comprising seven sandstone and four carbonate were analyzed. Pore network extraction from CT images was used to obtain detailed pore structure parameters and their statistical measures. Pore-scale simulations were conducted across 60 scenarios with varying average interstitial velocities and water as the injected fluid. Effluent hydrogen concentrations were measured to generate elution curves as a function of injected pore volumes (PV). This approach enables the assessment of the relationship between the dispersion coefficient and pore structure parameters across all rock samples at consistent average interstitial velocities. Additionally dispersivity and n-exponent values were calculated and correlated with pore structure parameters.

Urban air mobility (UAM) defined as safe and efficient air traffic operations in a metropolitan area for manned aircraft and unmanned aircraft systems is being researched and developed by industry academia and government. This kind of mobility offers an opportunity to construct a green and sustainable sub-sector building upon the lessons learned over decades by aviation. Thanks to their non-polluting operation and simple air traffic management electric vertical take-off and landing (eVTOL) aircraft technologies are currently being developed and experimented with for this purpose. However to successfully complete the certification and commercialization stage several challenges need to be overcome particularly in terms of performance such as flight time and endurance and reliability. In this paper a fast methodology for sizing and selecting the propulsion chain components of an eVTOL multirotor aerial vehicle was developed and validated on a reduced-scale prototype of an electric multirotor vehicle with a GTOW of 15 kg. This methodology is associated with a comparative study of energy storage system configurations in order to assess their effect on the flight time of the aerial vehicle. First the optimal pair motor/propeller was selected using a global nonlinear optimization in order to maximize the specific efficiency of these components. Second five energy storage technologies were sized in order to evaluate their influence on the aerial vehicle flight time. Finally based on this sizing process the optimized propulsion chain gross take-off weight (GTOW) was evaluated for each energy storage configuration using regression-based methods based on propulsion chain supplier data.

To facilitate the rapid and large-scale developments of offshore wind energy scholars policymakers and infrastructure developers must start considering its integration into the larger onshore energy system. Such offshore system integration is defined as the coordinated approach to planning and operation of energy generation transport and storage in the offshore energy system across multiple energy carriers and sectors. This article conducts a systematic literature review to identify infrastructure components of offshore energy system integration (including alternative cable connections offshore energy storage and power-to-hydrogen applications) and barriers to their development. An interdisciplinary perspective is provided where current offshore developments require not only mature and economically feasible technologies but equally strong legal and governance frameworks. The findings demonstrate that current literature lacks a holistic perspective on the offshore energy system. To date techno-economic assessments solving challenges of specific infrastructure components prevail over an integrated approach. Nevertheless permitting issues gaps in legal frameworks strict safety and environmental regulations and spatial competition also emerge as important barriers. Overall this literature review emphasizes the necessity of aligning various disciplines to provide a fundamental approach for the development of an integrated offshore energy system. More specifically timely policy and legal developments are key to incentivize technical development and enable economic feasibility of novel components of offshore system integration. Accordingly to maximize real-world application and policy learning future research will benefit from an interdisciplinary perspective.

Installations of decentralised renewable energy systems (RES) are becoming increasing popular as governments introduce ambitious energy policies to curb emissions and slow surging energy costs. This work presents a novel model for optimal sizing for a decentralised renewable generation and hybrid storage system to create a renewable energy community (REC) developed in Python. The model implements photovoltaic (PV) solar and wind turbines combined with a hybrid battery and regenerative hydrogen fuel cell (RHFC). The electrical service demand was derived using real usage data from a rural island case study location. Cost remuneration was managed with an REC virtual trading layer ensuring fair distribution among actors in accordance with the European RED(III) policy. A multi-objective genetic algorithm (GA) stochastically determines the system capacities such that the inherent trade-off relationship between project cost and decarbonisation can be observed. The optimal design resulted in a levelized cost of electricity (LCOE) of 0.15 EUR/kWh reducing costs by over 50% compared with typical EU grid power with a project internal rate of return (IRR) of 10.8% simple return of 9.6%/year and return on investment (ROI) of 9 years. The emissions output from grid-only use was reduced by 72% to 69 gCO2 e/kWh. Further research of lifetime economics and additional revenue streams in combination with this work could provide a useful tool for users to quickly design and prototype future decentralised REC systems.

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.

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.

Our Future Energy Scenarios (FES) outline four different credible pathways for the future of energy over the next 30 years. Based on input from over 600 experts the report looks at the energy needed in Britain across electricity and gas - examining where it could come from how it needs to change and what this means for consumers society and the energy system itself.

Increasing penetrations of renewable-based generation have led to a decrease in the bulk power system inertia and an increase in intermittency and uncertainty in generation. Energy storage is considered to be an important factor to help manage renewable energy generation at greater penetrations. Hydrogen is a viable long-term storage alternative. This paper analyzes and presents use cases for leveraging electrolyzer-based power-to-gas systems for electric grid support. The paper also discusses some grid services that may favor the use of hydrogenbased storage over other forms such as battery energy storage. Real-time controls are developed implemented and demonstrated using a power-hardware-in-the-loop(PHIL) setup with a 225-kW proton-exchange-membrane electrolyzer stack. These controls demonstrate frequency and voltage support for the grid for different levels of renewable penetration (0% 25% and 50%). A comparison of the results shows the changes in respective frequencies and voltages as seen as different buses as a result of support from the electrolyzers and notes the impact on hydrogen production as a result of grid support. Finally the paper discusses the practical nuances of implementing the tests with physical hardware such as inverter/electrolyzer efficiency as well as the related constraints and opportunities.

The production of hydrogen to be used as an alternative renewable energy has been widely explored. Among various methods for producing hydrogen from hydrocarbons methane decomposition is suitable for generating hydrogen with zero greenhouse gas emissions. The use of high temperatures as a result of strong carbon and hydrogen (C–H) bonds may be reduced by utilizing a suitable catalyst with appropriate catalyst support. Catalysts based on transition metals are preferable in terms of their activeness handling and low cost in comparison with noble metals. Further development of catalysts in methane decomposition has been investigated. In this review the recent progress on methane decomposition in terms of catalytic materials preparation method the physicochemical properties of the catalysts and their performance in methane decomposition were presented. The formation of carbon as part of the reaction was also discussed.

The H2-ICE project aims at developing through numerical simulation a new generation of hybrid powertrains featuring a hydrogen-fueled Internal Combustion Engine (ICE) suitable for 12 m urban buses in order to provide a reliable and cost-effective solution for the abatement of both CO2 and criteria pollutant emissions. The full exploitation of the potential of such a traction system requires a substantial enhancement of the state of the art since several issues have to be addressed. In particular the choice of a more suitable fuel injection system and the control of the combustion process are extremely challenging. Firstly a high-fidelity 3D-CFD model will be exploited to analyze the in-cylinder H2 fuel injection through supersonic flows. Then after the optimization of the injection and combustion process a 1D model of the whole engine system will be built and calibrated allowing the identification of a “sweet spot” in the ultra-lean combustion region characterized by extremely low NOx emissions and at the same time high combustion efficiencies. Moreover to further enhance the engine efficiency well above 40% different Waste Heat Recovery (WHR) systems will be carefully scrutinized including both Organic Rankine Cycle (ORC)-based recovery units as well as electric turbo-compounding. A Selective Catalytic Reduction (SCR) aftertreatment system will be developed to further reduce NOx emissions to near-zero levels. Finally a dedicated torque-based control strategy for the ICE coupled with the Energy Management Systems (EMSs) of the hybrid powertrain both optimized by exploiting Vehicle-To-Everything (V2X) connection allows targeting H2 consumption of 0.1 kg/km. Technologies developed in the H2-ICE project will enhance the know-how necessary to design and build engines and aftertreatment systems for the efficient exploitation of H2 as a fuel as well as for their integration into hybrid powertrains.

Austria is committed to the net-zero climate goal along with the European Union. This requires all sectors to be decarbonized. Hereby hydrogen plays a vital role as stated in the national hydrogen strategy. A report commissioned by the Austrian government predicts a minimum hydrogen demand of 16 TWh per year in Austria in 2040. Besides hydrogen imports domestic production can ensure supply. Hence this study analyses the levelized cost of hydrogen for an off-grid production plant including a proton exchange membrane electrolyzer wind power and solar photovoltaics in Austria. In the first step the capacity factors of the renewable electricity sources are determined by conducting a geographic information system analysis. Secondly the levelized cost of electricity for wind power and solarphotovoltaics plants in Austria is calculated. Thirdly the most cost-efficient portfolio of wind power and solar photovoltaics plants is determined using electricity generation profiles with a 10-min granularity. The modelled system variants differ among location capacity factors of the renewable electricity sources and the full load hours of the electrolyzer. Finally selected variables are tested for their sensitivities. With the applied model the hydrogen production cost for decentralized production plants can be calculated for any specific location. The levelized cost of hydrogen estimates range from 3.08 EUR/kg to 13.12 EUR/kg of hydrogen whereas it was found that the costs are most sensitive to the capacity factors of the renewable electricity sources and the full load hours of the electrolyzer. The novelty of the paper stems from the model applied that calculates the levelized cost of renewable hydrogen in an off-grid hydrogen production system. The model finds a cost-efficient portfolio of directly coupled wind power and solar photovoltaics systems for 80 different variants in an Austria-specific context.

This study aims to provide a comprehensive review of the potential of geothermal energy for producing hydrogen with a focus on the Australian context where low-temperature geothermal reservoirs particularly hot sedimentary aquifers (HSAs) are prevalent. The work includes an overview of various geothermal technologies and hydrogen production routes and evaluates potential alternatives for hydrogen production in terms of energy and exergy efficiency economic performance and hydrogen production rate. Values for energy efficiency are reported in the literature to range from 3.51 to 47.04% 7.4–67.5% for exergy efficiency a cost ranging from 0.59 to 5.97 USD/kg of hydrogen produced and a hydrogen production rate ranging from 0.11 to 5857 kg/h. In addition the article suggests and evaluates multiple metrics to appraise the feasibility of HSAs geothermal reservoirs with results tailored to Australia but that can be extended to jurisdictions with similar conditions worldwide. Furthermore the performance of various hydrogen production systems is investigated by considering important operating conditions. Lastly the key factors and possible solutions associated with the hydrogeological and financial conditions that must be considered in developing hydrogen production using lowtemperature geothermal energy are summarised. This study shows that low-temperature HSAs (~100 ◦C) can still be used for hydrogen generation via supplying power to conventional electrolysis processes by implementing several improvements in heat source temperature and energy conversion efficiency of Organic Rankine Cycle (ORC) power plants. Geothermal production from depleted or even active oilfields can reduce the capital cost of a hydrogen production system by up to 50% due to the use of pre-existing wellbores under the right operating conditions. Thus the results of this study bring novel insights in terms of both the opportunities and the challenges in producing clean hydrogen from geothermal energy applicable not only to the hydro-geological and socio-economic conditions in Australia but also worldwide exploring the applicability of geothermal energy for clean hydrogen production with similar geothermal potential.

In this episode Tony Green Hydrogen Director at National Grid and John Williams Head of Hydrogen Expertise Cluster at AFRYManagement Consulting join us to discuss the challenges in implementing hydrogen. Tony is involved in two exciting hydrogen projects: FutureGrid andProject Union. FutureGrid involves building a facility to create a representative whole-network to trial hydrogen. Project Union will develop a UK hydrogen ‘backbone’ joining together clusters around the country potentially creating a 2000km hydrogen network.

In addition to discussing these projects this episode will explore the following issues:

♦ Managing the transition and challenges in repurposing natural gas pipelines to hydrogen

♦ The potential for blending and de-blending hydrogen

♦ The impact of hydrogen on National Grid’s regulatory approach

♦ How to take the first steps towards a hydrogen wholesale market"

The podcast can be found on their website.

Hydrogen eliminates carbon emissions from compression ignition (CI) engines while noble gases eliminate nitrogen oxide (NOx) emissions by replacing nitrogen. Noble gases can increase the in-cylinder temperature during the compression stroke due to their high specific heat ratio. This paper aims to find the optimum parameters for hydrogen combustion in an argon–oxygen atmosphere and to study hydrogen combustion in all noble gases providing hydrogen combustion data with suitable engine parameters to predict hydrogen ignitability under different conditions. Simulations are performed with Converge CFD software based on the Yanmar NF19SK direct injection CI (DICI) engine parameters. The results are validated with the experimental results of hydrogen combustion in an argon–oxygen atmosphere with a rapid compression expansion machine (RCEM) and modifications of the hydrogen injection timing and initial temperature are proposed. Hydrogen ignition in an argon atmosphere is dependent on a minimum initial temperature of 340 K but the combustion is slightly unstable. Helium and neon are found to be suitable for hydrogen combustion in low compression ratio (CR) engines. However krypton and xenon require temperature modification and a high CR for stable ignition. Detailed parameter recommendations are needed to improve hydrogen ignitability in conventional diesel engines with the least engine modification.

The steelmaking industry is responsible for 7% of global CO2 emissions making decarbonization a significant challenge. This review provides a comprehensive analysis of current steel-production processes assessing their environmental impact in terms of CO2 emissions at a global level. Limitations of the current pathways are outlined by using objective criteria and a detailed review of the relevant literature. Decarbonization strategies are rigorously evaluated across various scenarios emphasizing technology feasibility. Focusing on three pivotal areas—scrap utilization hydrogen integration and electricity consumption—in-depth assessments are provided backed by notable contributions from both industrial and scientific fields. The intricate interplay of technical economic and regulatory considerations substantially affects CO2 emissions particularly considering the EU Emissions Trading System. Leading steel producers have established challenging targets for achieving carbon neutrality requiring a thorough evaluation of industry practices. This paper emphasizes tactics to be employed within short- medium- and long-term periods. This article explores two distinct case studies: One involves a hot rolling mill that utilizes advanced energy techniques and uses H2 for the reheating furnace resulting in a reduction of 229 kt CO2 -eq per year. The second case examines DRI production incorporating H2 and achieves over 90% CO2 reduction per ton of DRI.