Australia

This short film promotes Geoscience Australia's online and publicly accessible hydrogen data products. The film steps through the functionality of GA's Australian Hydrogen Opportunities Tool (AusH2) and describes the upcoming Hydrogen Economic Fairways Tool which has been created through a collaborative effort with Monash University.

Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources requiring additional CO2 capture to decarbonize which energy intense and costly. In a recent Green Energy & Environment paper Cheng and Di et al. proposed a novel integration process referred to as SECLRHC to generate high-purity H2 by in-situ separation of H2 and CO without using any additional separation unit. Theoretically the proposed process can essentially achieve the separation of C and H in gaseous fuel via a reconfigured reaction process and thus attaining high-purity hydrogen of ∼99% as well as good carbon and hydrogen utilization rates and economic feasibility. It displays an optimistic prospect that industrial decarbonization is not necessarily expensive as long as a suitable CCS measure can be integrated into the industrial manufacturing process.

Green hydrogen is a key element that has the potential to play a critical role in the global pursuit of a resilient and sustainable future. However like other energy production methods hydrogen comes with challenges including high costs and safety concerns across its entire value chain. To overcome these low-cost productions are required along with a promised market. Offshore renewables have an enormous potential to facilitate green hydrogen production on a large scale. Their plummeting cost technological advances and rising cost of carbon pave a pathway where green hydrogen can be cost-competitive against fossil-fuel-based hydrogen. Offshore industries including oil and gas aquaculture and shipping are looking for cleaner energy solutions to decarbonize their systems/operations and can serve as a substantial market. Offshore industrial nexus moreover can assist the production storage and transmission of green hydrogen through infrastructure sharing and logistical support. The development of offshore green hydrogen production facilities is in its infancy and requires a deeper insight into the key elements that govern decision-making during their life-cycle. This includes the parameters that reflect the performance of hydrogen technology with technical socio-political financial and environmental considerations. Therefore this study provides critical insight into the influential factors discovered through a comprehensive analysis that governs the development of an offshore green hydrogen system. Insights are also fed into the requirements for modelling and analysis of these factors considering the synergy of hydrogen production with the offshore industries coastal hydrogen hub and onshore energy demand. The results of this critical review will assist the researchers and developers in establishing and executing an effective framework for offshore site selection in largely uncertain and hazardous ocean environments. Overall the study will facilitate the stakeholders and researchers in developing decision-making tools to ensure sustainable and safe offshore green hydrogen facilities.

Modernising Australia’s old truck fleet and adopting a more stringent standard to reduce emissions and air pollutants is a primary objective for the Australian truck sector. Various strategies worldwide have been introduced to cut emissions and pollutants in the truck sector such as a low-emission strategy supported by strict diesel standards and a zero-emission strategy to shift to battery-electric or hydrogen trucks. The paper focuses on emissions and local air pollutants of trucks under various transition scenarios at both the tailpipe and the wider supply chain including domestic power generation and hydrogen production. In contrast for diesel we focus on tailpipe outputs following fuel standards in Australia given diesel is imported other than in some limited refineries. We compare and recommend actions that government and truck operators may take in the near to longer term in transitioning to cleaner energy. We tested a number of scenarios using a decision support system incorporating all the latest information on costs and emissions for all truck classes using diesel electric or hydrogen. A key finding from our scenario tests is that the current electricity mix has high carbon emissions and air pollutants due to fossil fuel-fired sources for power generation. Without improvement in using renewable energy sources in the future transitioning to electric trucks implies more carbon emissions and air pollutants in the atmosphere from power plants even though electric trucks generate zero tailpipe emissions. The main motivation for switching to zero-emission trucks is energy cost savings. We urge the government to decide on a clear roadmap for the truck sector before the sector is in a position to take action to shift to low or zero-emission trucks without totally relying on the likely reduction of emission intensity in electricity and renewable energy production.

Global supply chains must be decarbonised as part of meeting climate targets set by the United Nations and world leaders. Rail networks are vital infrastructure in passenger and freight transport however have not received the same push for decarbonisation as road transport. In this investigation we used real world data from locomotives operating on seven rail corridors to identify optimal battery capacity and hydrogen fuel cell (HFC) power in hybrid systems. We found that the required battery capacity is dependent on both the available regenerative braking energy and on the capacity required to buffer surpluses and deficits from the HFC. The optimal system for each corridor was identified however it was found that one 3.6 MWh battery and 860 kW HFC system could service six of the seven corridors. The optimal systems presented in this work suggest an average of around 5 h of battery storage for the HFC power which is larger than the 2 h previously reported in literature. This may indicate a gap between purely theoretical works that use only route topography and speed and those that employ real world locomotive data.

The demand for green hydrogen as an energy carrier is projected to exceed 350 million tons per year by 2050 driven by the need for sustainable distribution and storage of energy generated from sources. Despite its potential hydrogen production currently faces challenges related to cost efficiency compliance monitoring and safety. This work proposes Hydrogen 4.0 a cyber–physical approach that leverages Industry 4.0 technologies—including smart sensing analytics and the Internet of Things (IoT)—to address these issues in hydrogen energy plants. Such an approach has the potential to enhance efficiency safety and compliance through real-time data analysis predictive maintenance and optimised resource allocation ultimately facilitating the adoption of renewable green hydrogen. The following sections break down conventional hydrogen plants into functional blocks and discusses how Industry 4.0 technologies can be applied to each segment. The components benefits and application scenarios of Hydrogen 4.0 are discussed while how digitalisation technologies can contribute to the successful integration of sustainable energy solutions in the global energy sector is also addressed.

Hydrogen fuel cells power a range of vehicles including cars buses trucks forklifts and even trains. As fuel cell electric vehicles emit no carbon emissions and only produce water vapor as a by-product they present an attractive option for countries who are experiencing high pollution from transport. This paper presents the findings of ten focus groups and a subset of a national survey which focused specifically on use of hydrogen in the transport sector (N=948). When discussing hydrogen transport options Australian focus group participants felt that rolling out hydrogen fuel cell buses as a first step for fuel cell electric vehicle deployment would be a good way to increase familiarity with the technology. Deploying hydrogen public transport vehicles before personal vehicles was thought to be a positive way to demonstrate the safe use of hydrogen and build confidence in the technology. At the same time it was felt it would allow any issues to be ironed out before the roll out of large-scale infrastructure on a to support domestic use. Long haul trucks were also perceived to be a good idea however safety issues were raised in the focus groups when discussing these vehicles. Survey respondents also expressed positive support for the use of hydrogen fuel cell buses and long-haul trucks. They reported being happy to be a passenger in a fuel cell bus. Safety and environmental benefits remained paramount with cost considerations being the third most important issue. Respondents supportive of hydrogen technologies were most likely to report purchasing a hydrogen vehicle over other options

An adaptive response renewable energy plant (AREP) that provides grid balancing services and XeV station fuelling services (where “X” is any type) using renewable energy located in urban centres is described. The AREP has its own primary renewable energy sources and adapts operation in the short term to changing levels of excess or deficient energy on LV and MV electricity grids. The AREP adaptively responds by (1) storing excess energy in batteries for the short term and in hydrogen tanks after energy conversion by electrolysers for the long term; (2) returning power to the grid from either the AREP’s own primary (electron-based) energy sources or batteries and/or from hydrogen via conversion in fuel cells; (3) providing electricity for fast charging BeVs and PHeVs and hydrogen for FCeVs; and (4) exporting excess stored energy as hydrogen to domestic markets. The AREP also adapts over the long term by predictive planning of charging capacity such that the type and capacity of renewable energy equipment is optimised for future operations. A key advantage of this AREP configuration is a flexible “plug and play” capability with modular extension of energy assets. If the AREP footprint is constrained interaction with neighbouring AREPs as a mini-VPP-AREP network can assist in balancing short-term operating requirements. The benefits of this grid balancing and XeV renewable energy filling station or AREP are environmental social and economic through efficient functionality of appropriately sized components. AREPs provide a net zero emissions electricity solution to an existing network with short and long-term storage options as well as a net zero emissions fuel alternative to the transport sector while leveraging existing infrastructure with minimal upfront CAPEX. AREPs can give the flexibility a grid needs to enable high levels of renewable installations while developing green hydrogen production.

"Green hydrogen” i.e. hydrogen produced by splitting water with a carbon “free” source of electricity via electrolysis is set to become the energy vector enabling a deep decarbonisation of society and a virtuous water based energy cycle. If to date water electrolysis is considered to be a scalable technology the source of water to enable a “green hydrogen” economy at scale is questionable. Countries with the highest renewable energy potential like Australia are also among the driest places on earth. Globally 380000 GL/year of wastewater is available and this is much more than the 34500 GL/year of water required to produce the projected 2.3 Gt of hydrogen of a mature hydrogen economy. Hence the need to assess both technically and economically whether some wastewater treatment effluent are a better source for green hydrogen. Analysis of Sydney Water’s wastewater treatment plants alone shows that these plants have 37.6 ML/day of unused tertiary effluents which if electrolysed would generate 420000 t H2/day or 0.88 Mt H2/year and cover ∼100% of Australia’s estimated production by 2030. Furthermore the production of oxygen as a by-product of the electrolysis process could lead to significant benefits to the water industry not only in reducing the cost of the hydrogen produced for $3/kg (assuming a price of oxygen of $3–4 per kg) but also in improving the environmental footprint of wastewater treatment plants by enabling the onsite re-use of oxygen for the treatment of the wastewater. Compared to desalinated water that requires large investments or stormwater that is unpredictable it is apparent that the water utilities have a critical role to play in managing water assets that are “climate independent” as the next “golden oil” opportunity and in enabling a “responsible” hydrogen industry that sensibly manages its water demands and does not compete with existing water potable water demand.

The existing literature on the hydrogen supply chains has knowledge gaps. Most studies focus on hydrogen production storage transport and utilisation but neglect ports which are nexuses in the supply chains. To fill the gap this paper focuses on ports' readiness for the upcoming hydrogen international trade. Potential hydrogen exporting and importing ports are screened. Ports' readiness for hydrogen export and import are reviewed from perspectives of infrastructure risk management public acceptance regulations and standards and education and training. The main findings are: (1) liquid hydrogen ammonia methanol and LOHCs are suitable forms for hydrogen international trade; (2) twenty ports are identified that could be first movers; among them twelve are exporting ports and eight are importing ports; (3) ports’ readiness for hydrogen international trade is still in its infancy and the infrastructure construction or renovation risk management measures establishment of regulations and standards education and training all require further efforts.

Green Hydrogen (H2 via renewable-driven electrolysis) is emerging as a vector to meet net-zero emission targets provided it is produced with a low life cycle impact. While certification schemes for green H2 have been introduced they mainly focus on the embodied emissions from energy supply during electrolyser operation. This narrow focus on just operation is an oversight considering that a complete green H2 value chain also includes the electrolyser’s manufacturing transport/installation and end-of-life. Each step of this chain involves materials and energy flows that impart impacts that undermine the clean and sustainable status of H2. Therefore holistic and harmonised assessments of the green H2 production chain are required to ensure both economic and environmental deployment of H2. Herein we conduct an overarching environmental assessment encompassing the production chain described above using Australia as a case study. Our results indicate that while the energy source has the most impact material and manufacturing inputs associated with electrolyser production are increasingly significant as the scale of H2 output expands. Moreover wind power electrolysis has a greater chance of achieving green H2 certification compared to solar powered while increasing the amount of localised manufactured content and investment in end-of-life recycling of electrolyser components can reduce the overall life cycle impact of green H2 production by 20%.

Adopting proton exchange membrane fuel cells fuelled by hydrogen presents a promising solution for the shipping industry’s deep decarbonisation. However the potential safety risks associated with hydrogen leakage pose a significant challenge to the development of hydrogen-powered ships. This study examines the safe design principles and leakage risks of the hydrogen gas supply system of China’s first newbuilt hydrogen-powered ship. This study utilises the computational fluid dynamics tool FLACS to analyse the hydrogen dispersion behaviour and concentration distributions in the hydrogen fuel cell room based on the ship’s parameters. This study predicts the flammable gas cloud and time points when gas monitoring points first reach the hydrogen volume concentrations of 0.8% and 1.6% in various leakage scenarios including four different diameters (1 3 5 and 10 mm) and five different directions. This study’s findings indicate that smaller hydrogen pipeline diameters contribute to increased hydrogen safety. Specifically in the hydrogen fuel cell room a single-point leakage in a hydrogen pipeline with an inner diameter not exceeding 3 mm eliminates the possibility of flammable gas cloud explosions. Following a 10 mm leakage diameter the hydrogen concentration in nearly all room positions reaches 4.0% within 6 s of leakage. While the leakage diameter does not impact the location of the monitoring point that first activates the hydrogen leak alarm and triggers an emergency hydrogen supply shutdown the presence of obstructions near hydrogen detectors and the leakage direction can affect it. These insights provide guidance on the optimal locations for hydrogen detectors in the fuel cell room and the pipeline diameters on hydrogen gas supply systems which can facilitate the safe design of hydrogen-powered ships.

Conventional fuels for vehicular applications generate hazardous pollutants which have an adverse effect on the environment. Therefore there is a high demand to shift towards environment-friendly vehicles for the present mobility sector. This paper highlights sustainable mobility and specifically sustainable transportation as a solution to reduce GHG emissions. Thus hydrogen fuel-based vehicular technologies have started blooming and have gained significance following the zero-emission policy focusing on various types of sustainable motilities and their limitations. Serving an incredible deliverance of energy by hydrogen fuel combustion engines hydrogen can revolution various transportation sectors. In this study the aspects of hydrogen as a fuel for sustainable mobility sectors have been investigated. In order to reduce the GHG (Green House Gas) emission from fossil fuel vehicles researchers have paid their focus for research and development on hydrogen fuel vehicles and proton exchange fuel cells. Also its development and progress in all mobility sectors in various countries have been scrutinized to measure the feasibility of sustainable mobility as a future. This paper is an inclusive review of hydrogen-based mobility in various sectors of transportation in particular fuel cell cars that provides information on various technologies adapted with time to add more towards perfection. When compared to electric vehicles with a 200-mile range fuel cell cars have a lower driving cost in all of the 2035 and 2050 scenarios. To stimulate the use of hydrogen as a passenger automobile fuel the cost of a hydrogen fuel cell vehicle (FCV) must be brought down to at least the same level as an electric vehicle. Compared to gasoline cars fuel cell vehicles use 43% less energy and generate 40% less CO2.

Energy plays a crucial role in the sustainable development of modern nations. Today hydrogen is considered the most promising alternative fuel as it can be generated from clean and green sources. Moreover it is an efficient energy carrier because hydrogen burning only generates water as a byproduct. Currently it is generated from natural gas. However it can be produced using other methods i.e. physicochemical thermal and biological. The biological method is considered more environmentally friendly and pollution free. This paper aims to provide an updated review of biohydrogen production via photofermentation dark fermentation and microbial electrolysis cells using different waste materials as feedstocks. Besides the role of nanotechnology in enhancing biohydrogen production is examined. Under anaerobic conditions hydrogen is produced during the conversion of organic substrate into organic acids using fermentative bacteria and during the conversion of organic acids into hydrogen and carbon dioxide using photofermentative bacteria. Different factors that enhance the biohydrogen production of these organisms either combined or sequentially using dark and photofermentation processes are examined and the effect of each factor on biohydrogen production efficiency is reported. A comparison of hydrogen production efficiency between dark fermentation photofermentation and two-stage processes is also presented.

Decarbonisation of heavy haul rail is an essential contributor to a zero-emissions future. However the transition from diesel to battery locomotives is not always practical given the unique characteristics of each haul. This paper demonstrates the limitations of state-of-the-art batteries using real-world data from multiple locomotives operating in Australian rail freight. An energy model was developed to assess each route’s required energy and potential regenerated energy. The tractive and regenerative battery energy mass and cost were determined using data from the energy model coupled with battery specifications. The feasibility of implementing lithium iron phosphate (LFP) nickel manganese cobalt (NMC) and lithium titanium oxide (LTO) chemistries was explored based on cost energy density cycle lifespan and locomotive data. LFP was identified as the most suitable current battery solution based on current chemistries. Further examination of the energy demands and associated mass/volume constraints concluded that three platforms are required for heavy haul rail decarbonisation i) a battery electric locomotive for low-energy demands which can be coupled with either ii) a battery electric tender for medium energy demands or iii) a hydrogen fuel cell electric tender for higher energy demands. A future-looking techno-economic assessment of battery and hydrogen fuel cell platforms concludes that the lowest cost solution for low-energy hauls is a battery-only system and for high-energy hauls a battery-hydrogen system.

Ammonia plays a vital role in feeding the world through fertilizer production as well as having other industrial uses. However current ammonia production processes rely heavily on fossil fuels mostly natural gas to generate hydrogen as a feedstock. There is an urgent need to re-design and decarbonise the production process to reduce greenhouse emissions and avoid dependence on volatile gas markets and a depleting resource base. Renewable energy driven electrolysis to generate hydrogen provides a viable pathway for producing carbon-free or green ammonia. However a key challenge associated with producing green ammonia is managing low cost but highly variable wind and solar renewable energy generation for hydrogen electrolysis while maintaining reliable operation of the less flexible ammonia synthesis unit. To date green ammonia production has only been demonstrated at pilot scale and optimising plant configurations and scaling up production facilities is an urgent task. Existing feasibility studies have demonstrated the ability to model and cost green ammonia production pathways that can overcome the technical and economic challenges. However these existing approaches are context specific demonstrating the ability to model and cost green ammonia production for defined locations with set configurations. In this paper we present a modelling framework that consolidates the array of configurations previously studied into a single framework that can be tailored to the location of interest. Our open-source green ammonia modelling and costing tool dynamically simulates the integration of renewable energy with a wide range of balancing power and storage options to meet the flexible demands of the green ammonia production process at hourly time resolution over a year or more. Unlike existing models the open-source implementation of our tool allows it to be used by a potentially wide range of stakeholders to explore their own projects and help guide the upscaling of green ammonia as a pathway for decarbonisation. Using Gladstone in Australia as a case study a 1 million tonne per annum (MMTPA) green ammonia plant is modelled and costed using price assumptions for major equipment in 2030 provided by the Australian Energy Market Operator (AEMO). Using a hybrid (solar PV and wind) renewable energy source and Battery Energy Storage System as balancing technology we estimate a levelized cost of ammonia (LCOA) between 0.69 and 0.92 USD kgNH3 -1 . While greater than historical ammonia production costs from natural gas falling renewables costs and emission reduction imperatives suggest a major future role for green ammonia.

There is significant interest in Australia both federally and at the state level to develop a hydrogen production industry. Australia’s Chief Scientist Alan Finkel recently prepared a briefing paper for the COAG Energy Council outlining a road map for hydrogen. It identifies hydrogen has the potential to be a significant source of export revenue for Australia in future years assist with decarbonising Australia’s economy and could establish Australia as a leader in low emission fuel production.

As part of the ongoing investigations into the hydrogen production potential of Australia Geoscience Australia has been commissioned by the Department of Industry Innovation and Science to develop heat maps that show areas with high potential for future hydrogen production. The study is technology agnostic in that it considers hydrogen production via electrolysis using renewable energy sources and also fossil fuel hydrogen coupled with carbon capture and storage (CCS). The heat maps presented in this work are synthesized from the key individual national-scale datasets that are relevant for hydrogen production. In the case of hydrogen from electrolysis renewable energy potential and the availability of water are the most important factors with various infrastructural considerations playing a secondary role. In the case of fossil fuel hydrogen proximity to gas and coal resources water and availability of carbon storage sites are the important parameters that control the heat maps. In this report we present 5 different heat map scenarios reflecting different assumptions in the geospatial analysis and also reflecting to some degree the different projected timeframes for hydrogen production. The first three scenarios pertain to renewable energy and hydrogen There is significant interest in Australia both federally and at the state level to develop a hydrogen production industry. In August 2018 Australia’s Chief Scientist Dr Alan Finkel prepared a briefing paper for the COAG Energy Council outlining a road map for hydrogen. It identifies hydrogen has the potential to be a significant source of export revenue for Australia in future years assist with decarbonising Australia’s economy and could establish Australia as a leader in low emission fuel production.

As part of ongoing investigations into the hydrogen production potential of Australia Geoscience Australia has been engaged by the Department of Industry Innovation and Science to develop maps that show areas with high potential for future hydrogen production. The study is technology agnostic but considers only low carbon production processes. It includes hydrogen production via electrolysis using renewable energy sources (referred to as renewable hydrogen) as well as fossil fuel-derived hydrogen coupled with carbon capture and storage (CCS) (referred to as CCS hydrogen). The maps presented in this work are synthesized from the key individual national-scale datasets that are relevant for hydrogen production. In the case of hydrogen from electrolysis renewable energy potential (from wind solar and hydro resources) and the availability of water are the most important factors while various infrastructure considerations also play a role. In the case of CCS hydrogen proximity to gas and coal resources water and availability of carbon storage sites are the important parameters that control the spatial distribution of potential hydrogen production. In this report we present five different scenarios that reflect key differences in technologies for hydrogen production and the requirements of those technologies. Using geospatial analysis each scenario is translated into a heat map that shows regional trends in potential for hydrogen production based on access to underpinning resources and existing infrastructure.

Three scenarios explore the future potential for renewable hydrogen produced by electrolysis. These demonstrate a high potential for hydrogen production in the future near many Australian coastal areas which is even larger if infrastructure is available to transport renewable power generated from inland areas to the coast. Results also show significant future potential for hydrogen production in inland areas where water is available. The final two scenarios focus on the future potential for CCS hydrogen: a 2030 scenario and a 2050 scenario. A key factor in future CCS hydrogen potential is related to the timeframes for the availability of geological storage resources for CO_2.

Carbon-based nanocomposites have developed as the most promising and emerging materials in nanoscience and technology during the last several years. They are microscopic materials that range in size from 1 to 100 nanometers. They may be distinguished from bulk materials by their size shape increased surface-to-volume ratio and unique physical and chemical characteristics. Carbon nanocomposite matrixes are often created by combining more than two distinct solid phase types. The nanocomposites that were constructed exhibit unique properties such as significantly enhanced toughness mechanical strength and thermal/electrochemical conductivity. As a result of these advantages nanocomposites have been used in a variety of applications including catalysts electrochemical sensors biosensors and energy storage devices among others. This study focuses on the usage of several forms of carbon nanomaterials such as carbon aerogels carbon nanofibers graphene carbon nanotubes and fullerenes in the development of hydrogen fuel cells. These fuel cells have been successfully employed in numerous commercial sectors in recent years notably in the car industry due to their cost-effectiveness eco-friendliness and long-cyclic durability. Further; we discuss the principles reaction mechanisms and cyclic stability of the fuel cells and also new strategies and future challenges related to the development of viable fuel cells.

Hydrogen has received tremendous global attention as an energy carrier and an energy storage system. Hydrogen carrier introduces a power to hydrogen (P2H) and power to hydrogen to power (P2H2P) facility to store the excess energy in renewable energy storage systems with the facts of large-scale storage capacity transportability and multiple utilities. This work examines the techno-economic feasibility of hybrid solar photovoltaic (PV)/hydrogen/fuel cell-powered cellular base stations for developing green mobile communication to decrease environmental degradation and mitigate fossil-fuel crises. Extensive simulation is carried out using a hybrid optimization model for electric renewables (HOMER) optimization tool to evaluate the optimal size energy production total production cost per unit energy production cost and emission of carbon footprints subject to different relevant system parameters. In addition the throughput and energy efficiency performance of the wireless network is critically evaluated with the help of MATLAB-based Monte-Carlo simulations taking multipath fading system bandwidth transmission power and inter-cell interference (ICI) into consideration. Results show that a more stable and reliable green solution for the telecommunications sector will be the macro cellular basis stations driven by the recommended hybrid supply system. The hybrid supply system has around 17% surplus electricity and 48.1 h backup capacity that increases the system reliability by maintaining a better quality of service (QoS). To end the outcomes of the suggested system are compared with the other supply scheme and the previously published research work for justifying the validity of the proposed system.

Currently hydrogen energy is the most promising energy vector while gasification is one of the major routes for its production. However gasification suffers from various issues including slower carbon conversion poor syngas quality lower heating value and higher emissions. Multiple factors affect gasification performance such as the selection of gasifiers feedstock’s physicochemical properties and operating conditions. In this review the status of gasification key gasifier technologies and the effect of solid-fuel (i.e. coal biomass and MSW) properties on gasification performance are reviewed critically. Based on the current review the co-gasification of coal biomass and solid waste along with a partial utilisation of CO2 as a reactant are suggested. Furthermore a technological breakthrough in carbon capture and sequestration is needed to make it industrially viable

Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets delivering low carbon heat and power decarbonising industry and more recently its ability to facilitate the net removal of CO₂ from the atmosphere. However despite this broad consensus and its technical maturity CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus in this paper we review the current state-of-the-art of CO₂ capture transport utilisation and storage from a multi-scale perspective moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS) and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.

The global energy crisis and environmental pollution have caused great concern. Hydrogen is a renewable and environmentally friendly source of energy and has potential to be a major alternative energy carrier in the future. Due to its high capacity and relatively low cost of raw materials alanate has been considered as one of the most promising candidates for hydrogen storage. Among them LiAlH₄ and NaAlH₄ as two representative metal alanates have attracted extensive attention. Unfortunately the high desorption temperature and sluggish kinetics restrict its practical application. In this paper the basic physical and chemical properties as well as the hydrogenation/dehydrogenation reaction mechanism of LiAlH₄ and NaAlH₄ are briefly reviewed. The recent progress on strategic optimizations toward tuning the thermodynamics and kinetics of the alanate including nanoscaling doping catalysts and compositing modification are emphatically discussed. Finally the coming challenges and the development prospects are also proposed in this review.

The use of hydrogen energy and the associated technologies is expected to increase in the coming years. The success of hydrogen energy technology (HET) is however dependent on public acceptance of the technology. Developing this new industry in a socially responsible way will require an understanding of the psychology factors that may facilitate or impede its public acceptance. This paper reviews 27 quantitative studies that have explored the relationship between psychological factors and HET acceptance. The findings from the review suggest that the perceived effects of the technology (i.e. the perceived benefits costs and risks) and the associated emotions are strong drivers of HET acceptance. This paper does though highlight some limitations with past research that make it difficult to make strong conclusions about the factors that influence HET acceptance. The review also reveals that few studies have investigated acceptance of different types of HET beyond a couple of applications. The paper ends with a discussion about directions for future research and highlights some practical implications for messaging and policy.

Hydrogen as the International Energy Agency (IEA 2019) notes has experienced a number of ‘false dawns’ - in the 1970s 1990s and early 2000s - which subsequently faded. However this time there is reason to think that hydrogen will play a substantial role in the global energy system. The most important factor driving this renewed focus is the ability of hydrogen to support deep carbon abatement by assisting in those sectors where abatement with non-carbon electricity has so far proven difficult. Hydrogen can also address poor urban air quality energy security and provides a good means of shifting energy supply between regions and between seasons.

In response to these changed conditions many countries states and even cities have developed hydrogen strategies while various interest groups have developed industry roadmaps which fulfil a similar role.  

This report summarises 19 hydrogen strategies and aims to help readers understand how nations regions and industries are thinking about opportunities to become involved in this emerging industry. Its prime purpose is to act as a resource to assist those involved in long-term energy policy planning in Australia including those involved in the development of Australia’s hydrogen strategy

The full report can be read on the Energy Network website at this link here

Power to hydrogen (P2H) provides a promising solution to the geographic mismatch between sources of renewable energy and the market due to its technological maturity flexibility and the availability of technical and economic data from a range of active demonstration projects. In this review we aim to provide an overview of the status of P2H analyze its technical barriers and solutions and propose potential opportunities for future research and industrial demonstrations. We specifically focus on the transport of hydrogen via natural gas pipeline networks and end-user purification. Strong evidence shows that an addition of about 10% hydrogen into natural gas pipelines has negligible effects on the pipelines and utilization appliances and may therefore extend the asset value of the pipelines after natural gas is depleted. To obtain pure hydrogen from hydrogen-enriched natural gas (HENG) mixtures end-user separation is inevitable and can be achieved through membranes adsorption and other promising separation technologies. However novel materials with high selectivity and capacity will be the key to the development of industrial processes and an integrated membrane-adsorption process may be considered in order to produce high-purity hydrogen from HENG. It is also worth investigating the feasibility of electrochemical separation (hydrogen pumping) at a large scale and its energy analysis. Cryogenics may only be feasible when liquefied natural gas (LNG) is one of the major products. A range of other technological and operational barriers and opportunities such as water availability byproduct (oxygen) utilization and environmental impacts are also discussed. This review will advance readers’ understanding of P2H and foster the development of the hydrogen economy.

About 400 million tonnes of plastics are produced per annum worldwide. End-of-life of plastics disposal contaminates the waterways aquifers and limits the landfill areas. Options for recycling plastic wastes include feedstock recycling mechanical /material recycling industrial energy recovery municipal solid waste incineration. Incineration of plastics containing E-Wastes releases noxious odours harmful gases dioxins HBr polybrominated diphenylethers and other hydrocarbons. This study focusses on recycling options in particular feedstock recycling of plastics in high-temperature materials processing for a sustainable solution to the plastic wastes not suitable for recycling. Of the 7% CO₂ emissions attributed to the iron and steel industry worldwide ∼30% of the carbon footprint is reduced using the waste plastics compared to other carbon sources in addition to energy savings. Plastics have higher H₂ content than the coal. Hydrogen evolved from the plastics acts as the reductant alongside the carbon monoxide. Hydrogen reduction of iron ore in presence of plastics increases the reaction rates due to higher diffusion of H₂ compared to CO. Plastic replacement reduces the process temperature by at least 100–200 °C due to the reducing gases (hydrogen) which enhance the energy efficiency of the process. Similarly plastics greatly reduce the emissions in other high carbon footprint process such as magnesia production while contributing to energy.

Hydrogen energy as a clean and renewable energy has attracted much attention in recent years. Water electrolysis via the hydrogen evolution reaction at the cathode coupled with the oxygen evolution reaction at the anode is a promising method to produce hydrogen. Given the shortage of freshwater resources on the planet the direct use of seawater as an electrolyte for hydrogen production has become a hot research topic. Direct use of seawater as the electrolyte for water electrolysis can reduce the cost of hydrogen production due to the great abundance and wide availability. In recent years various high-efficiency electrocatalysts have made great progress in seawater splitting and have shown great potential. This review introduces the mechanisms and challenges of seawater splitting and summarizes the recent progress of various electrocatalysts used for hydrogen and oxygen evolution reaction in seawater electrolysis in recent years. Finally the challenges and future opportunities of seawater electrolysis for hydrogen and oxygen production are presented.

The report investigates a kickstart project that allows up to 10% hydrogen into gas distribution networks. It reviews the technical impacts and standards to identify barriers and develop recommendations.

You can see the full report on the Australian Government website here 

This report is developed in support of Australia's National Hydrogen Strategy

The report documents current knowledge of the social issues surrounding hydrogen projects. It reviews leading practice stakeholder engagement and communication strategies and findings from focus groups and research activities across Australia.

The full report can be found at this link.

Hydrogen is fast becoming a new international “super fuel” to accelerate global climate change ambitions. This paper has two inter-weaving themes. Contextually it focuses on the potential impact of the EU’s new Carbon Border Adjustment Mechanism (CBAM) on fossil fuel-generated as opposed to green hydrogen imports. The CBAM as a transnational carbon adjustment mechanism has the potential to impact international trade in energy. It seeks both a level playing field between imports and EU internal markets (subject to ambitious EU climate change policies) and to encourage emissions reduction laggards through its “carbon diplomacy”. Countries without a price on carbon will be charged for embodied carbon in their supply chains when they export to the EU. Empirically we focus on two hydrogen export/import case studies: Australia as a non-EU state with ambitions to export hydrogen and Germany as an EU Member State reliant on energy imports. Energy security is central to energy trade debates but needs to be conceptualized beyond supply and demand economics to include geopolitics just transitions and the impacts of border carbon taxes and EU carbon diplomacy. Accordingly we apply and further develop a seven-dimension energy security-justice framework to the examples of brown blue and green hydrogen export/import hydrogen operations with varying carbon-intensity supply chains in Australia and Germany. Applying the framework we identify potential impact—risks and opportunities—associated with identified brown blue and green hydrogen export/import projects in the two countries. This research contributes to the emerging fields of international hydrogen trade supply chains and international carbon diplomacy and develops a potentially useful seven-dimension energy security-justice framework for energy researchers and policy analysts.

Renewable green fuels (RGF) such as hydrogen are the global energy future. Air pollution is compounded with climate change as the emissions driving both development problems come largely from the same source of fossil fuel burning. As an energy exporter Australian energy export dominates the total energy production and the RGF has become central to the current proposal of Australian government to reach net zero emission. The hydrogen production from solar panels only on 3% of Australia's land area could compensate 10 times of Germany's non-electricity energy consumption. In the unique geographic position Australia's RGF export attracts significant costs for long distance onboard storage and shipping. While the cost reduction of RGF production relies on technological advancement which needs a long time the storage and shipping costs must be minimised for Australia to remain competitive in the global energy market. The present review concentrates on Australian export pathways of lifecycles of liquid renewable green fuels including renewable liquified hydrogen (LH2) liquified methane (LCH4) ammonia (NH3) and methanol (CH3OH) as liquid RGF have the advantages of adopting the existing infrastructure. This review compares the advantages and disadvantages of discussed renewable energy carriers. It is found that the cost of LH2 pathway can be acceptable for shipping distance of up to 7000 km (Asian countries such as Japan) but ammonia (NH3) or methanol (CH3OH) pathways may be more cost effective for shipping distance above 7000 km for European counties such as Germany. These observations suggest the proper fuel forms to fulfill the requirements to different customers and hence will highlight Australia's position as one of major exporters of renewable energy in the future. Detailed techno-economic analysis is worth to be done for supplying more quantitative results.

This study uses an online quasi-experiment with a national sample from Australia to evaluate public acceptance of hydrogen exports. It explores the complex communications environment that messaging about hydrogen exports is typically encountered in. We find that acceptance of green hydrogen exports is significantly higher than blue or brown hydrogen exports and acceptance of blue hydrogen exports higher than brown hydrogen exports. Additionally results show economic-framed benefit messages are associated with lesser public acceptance when encountered in communication contexts that outline differently-focused environmental downsides (competing contexts) but not same-focused economic downsides (conflicting contexts). In contrast environment-framed benefit messages are associated with lesser public acceptance when presented in communication contexts that outline same-focused environmental downsides (conflicting contexts) but not differentlyfocused economic downsides (competing contexts). Overall the study indicates message framing can impact acceptance of hydrogen exports and that organisations should consider the informational context within which their communications will be received.

Devices enabling early detection of low concentrations of leaking hydrogen and precision measurements in a wide range of hydrogen concentrations in hydrogen storage systems are essential for the mass-production of fuel-cell vehicles and more broadly for the transition to the hydrogen economy. Whereas several competing sensor technologies are potentially suitable for this role ultralow fire-hazard contactless and technically simple magneto-electronic sensors stand apart because they have been able to detect the presence of hydrogen gas in a range of hydrogen concentrations from 0.06% to 100% at atmospheric pressure with the response time approaching the industry gold standard of one second. This new kind of hydrogen sensors is the subject of this review article where we inform academic physics chemistry material science and engineering communities as well as industry researchers about the recent developments in the field of magneto-electronic hydrogen sensors including those based on magneto-optical Kerr effect anomalous Hall effect and Ferromagnetic Resonance with a special focus on Ferromagnetic Resonance (FMR)-based devices. In particular we present the physical foundations of magneto-electronic hydrogen sensors and we critically overview their advantages and disadvantages for applications in the vital areas of the safety of hydrogen-powered cars and hydrogen fuelling stations as well as hydrogen concentration meters including those operating directly inside hydrogen-fuelled fuel cells. We believe that this review will be of interest to a broad readership also facilitating the translation of research results into policy and practice.

Green ammonia has received increasing interest for its potential as an energy carrier in the international trade of renewable power. This paper considers the factors that contribute to producing cost-competitive green ammonia from an exporter’s perspective. These factors include renewable resource quality across potential sites operating modes for off-grid plants and seasonal complementarity with trade buyers. The study applies a mixed-integer programming model and uses Australia as a case study because of its excellent solar and wind resources and the potential for synergy between Southern Hemisphere supply and Northern Hemisphere demand. Although renewable resources are unevenly distributed across Australia and present distinct diurnal and seasonal variability modelling shows that most of the pre-identified hydrogen hubs in each state and territory of Australia can produce cost-competitive green ammonia providing the electrolysis and Haber-Bosch processes are partially flexible to cope with the variability of renewables. Flexible operation reduces energy curtailment and leads to lower storage capacity requirements using batteries or hydrogen storage which would otherwise increase system costs. In addition an optimised combination of wind and solar can reduce the magnitude of storage required. Providing that a partially flexible Haber Bosch plant is commercially available the modelling shows a levelised cost of ammonia (LCOA) of AU$756/tonne and AU$659/tonne in 2025 and 2030 respectively. Based on these results green ammonia would be cost-competitive with grey ammonia in 2030 given a feedstock natural gas price higher than AU$14/MBtu. For green ammonia to be cost-competitive with grey ammonia assuming a lower gas price of AU$6/MBtu a carbon price would need to be in place of at least AU$123/tonne. Given that there is a greater demand for energy in winter concurrent with lower solar power production there may be opportunities for solar-based Southern Hemisphere suppliers to supply the major industrial regions most of which are located in the Northern Hemisphere.

Currently renewable energy-based generators are considered worldwide to achieve net zero targets. However the stochastic nature of renewable energy systems leads to regulation and control challenges for power system operators especially in remote and regional grids with smaller footprints. A hybrid system (i.e. solar wind biomass energy storage) could minimise this issue. Nevertheless the hybrid system is not possible to develop in many islands due to the limited land area geographical conditions and others. Hydrogen as a carrier of clean energy can be used in locations where the installation of extensive or medium-scale renewable energy facilities is not permissible due to population density geographical constraints government policies and regulatory issues. This paper presents a techno-economic assessment of designing a green hydrogen-based microgrid for a remote island in North-east Australia. This research work determines the optimal sizing of microgrid components using green hydrogen technology. Due to the abovementioned constraints the green hydrogen production system and the microgrid proposed in this paper are located on two separate islands. The paper demonstrates three cost-effective scenarios for green hydrogen production transportation and electricity generation. This work has been done using Hybrid Optimisation Model for Multiple Energy Resources or HOMER Pro simulation platform. Simulation results show that the Levelized Cost of Energy using hydrogen technology can vary from AU$0.37/kWh to AU$1.08/kWh depending on the scenarios and the variation of key parameters. This offers the potential to provide lower-cost electricity to the remote community. Furthermore the CO2 emission could be reduced by 1760777 kg/year if the renewable energy system meets 100% of the electricity demand. Additionally the sensitivity analysis in this paper shows that the size of solar PV and wind used for green hydrogen production can further be reduced by 50%. The sensitivity analysis shows that the system could experience AU$0.03/kWh lower levelized cost if the undersea cable is used to transfer the generated electricity between islands instead of hydrogen transportation. However it would require environmental approval and policy changes as the islands are located in the Great Barrier Reef.

Hydrogen (H2) is currently considered a clean fuel to decrease anthropogenic greenhouse gas emissions and will play a vital role in climate change mitigation. Nevertheless one of the primary challenges of achieving a complete H2 economy is the large-scale storage of H2 which is unsafe on the surface because H2 is highly compressible volatile and flammable. Hydrogen storage in geological formations could be a potential solution to this problem because of the abundance of such formations and their high storage capacities. Wettability plays a critical role in the displacement of formation water and determines the containment safety storage capacity and amount of trapped H2 (or recovery factor). However no comprehensive review article has been published explaining H2 wettability in geological conditions. Therefore this review focuses on the influence of various parameters such as salinity temperature pressure surface roughness and formation type on wettability and consequently H2 storage. Significant gaps exist in the literature on understanding the effect of organic material on H2 storage capacity. Thus this review summarizes recent advances in rock/H2/brine systems containing organic material in various geological reservoirs. The paper also presents influential parameters affecting H2 storage capacity and containment safety including liquid–gas interfacial tension rock–fluid interfacial tension and adsorption. The paper aims to provide the scientific community with an expert opinion to understand the challenges of H2 storage and identify storage solutions. In addition the essential differences between underground H2 storage (UHS) natural gas storage and carbon dioxide geological storage are discussed and the direction of future research is presented. Therefore this review promotes thorough knowledge of UHS provides guidance on operating large-scale UHS projects encourages climate engineers to focus more on UHS research and provides an overview of advanced technology. This review also inspires researchers in the field of climate change to give more credit to UHS studies.

As a fuel for power generation high-pressure hydrogen gas is widely used for transportation and its efficient storage promotes the development of fuel cell vehicles (FCVs). However as the filling process takes such a short time the maximum temperature in the storage tank usually undergoes a rapid increase which has become a thorny problem and poses great technical challenges to the steady operation of hydrogen FCVs. For security reasons SAE J2601/ISO 15869 regulates a maximum temperature limit of 85 ◦C in the specifications for refillable hydrogen tanks. In this paper a two-dimensional axisymmetric and a three-dimensional numerical model for fast charging of Type III 35 MPa and 70 MPa hydrogen vehicle cylinders are proposed in order to effectively evaluate the temperature rise within vehicle tanks. A modified standard k-ε turbulence model is utilized to simulate hydrogen gas charging. The equation of state for hydrogen gas is adopted with the thermodynamic properties taken from the National Institute of Standards and Technology (NIST) database taking into account the impact of hydrogen gas’ compressibility. To validate the numerical model three groups of hydrogen rapid refueling experimental data are chosen. After a detailed comparison it is found that the simulated results calculated by the developed numerical model are in good agreement with the experimental results with average temperature differences at the end time of 2.56 K 4.08 K and 4.3 K. The present study provides a foundation for in-depth investigations on the structural mechanics analysis of hydrogen gas vessels during fast refueling and may supply some technical guidance on the design of charging experiments.

The integration of electrolyzers and fuel cells can cause voltage fluctuations within microgrids if not properly scheduled. Therefore controlling voltage and reactive power becomes crucial to mitigate the impact of fluctuating voltage levels ensuring system stability and preventing damage to equipment. This paper therefore seeks to enhance voltage and reactive power control within reconfigurable microgrids in the presence of innovative power-to-hydrogen technologies via electrolyzers and hydrogen-to-power through fuel cells. Specifically it focuses on the simultaneous coordination of an electrolyzer hydrogen storage and a fuel cell alongside on-load tap changers smart photovoltaic inverters renewable energy sources diesel generators and electric vehicle aggregation within the microgrid system. Additionally dynamic network reconfiguration is employed to enhance microgrid flexibility and improve the overall system adaptability. Given the inherent unpredictability linked to resources the unscented transformation method is employed to account for these uncertainties in the proposed voltage and reactive power management. Finally the model is formulated as a convex optimization problem and is solved through GUROBI version 11 which leads to having a time-efficient model with high accuracy. To assess the effectiveness of the model it is eventually examined on a modified 33-bus microgrid in several cases. Through the results of the under-study microgrid the developed model is a great remedy for the simultaneous operation of diverse resources in reconfigurable microgrids with a flatter voltage profile across the microgrid.

Growing interest in sustainable energy has gathered significant attention for alternative technologies with hydrogen-based solutions emerging as a crucial component in the transition to cleaner and more resilient energy systems. Following that hydrogenbased microgrids integrated with renewable energy sources including wind and solar have gained substantial attention as an upcoming pathway toward long-term energy sustainability. Hydrogen produced through processes such as electrolysis and steam methane reforming can be stored in various forms including compressed gas liquid or solid-state hydrides and later utilized for electricity generation through fuel cells and gas turbines. This dynamic energy system offers highly flexible scalable and resilient solutions for various applications. Specifically hydrogen-based microgrids are particularly suitable for offshore and islanded applications with geographical factors adverse environmental conditions and limited access to conventional energy solutions. This is critical for energy independence long-term storage capacity and grid stability. This review explores topological and functional-based classifications of microgrids advancements in hydrogen generation storage and utilization technologies and their integration with microgrid systems. It also critically evaluates the key challenges of each technology including cost efficiency and scalability which impact the feasibility of hydrogen microgrids.

The increasing global residential energy demand causes carbon emissions and ecological impacts necessitating cleaner efficient solutions. This study presents an innovative hybrid energy system integrating wind power and gas turbines for a four-story 16-unit residential building. The system generates electricity heating cooling and hydrogen using a Proton Exchange Membrane electrolyzer and a compression chiller. Integrating the electrolyzer enables hydrogen production and demonstrates hydrogen’s potential as a versatile clean energy carrier for systems contributing to advancements in hydrogen utilization. Simulations with Engineering Equation Solver software coupled with neural network-based multi-objective optimization fine-tuned parameters such as gas turbine efficiency wind turbine count and gas turbine inlet temperature to enhance exergy efficiency and reduce operational costs. The optimized system achieves an energy efficiency of 33.69% and an exergy efficiency of 36.95% and operates at $446.04 per hour demonstrating economic viability. It produces 51061 MWh annually exceeding the building’s energy demands and allowing surplus energy use elsewhere. BEopt simulations confirm the system meets residential needs by providing 2.52 GWh of electricity 3.36 GWh of heating and 5.11 GWh of cooling annually. This system also generates 10 kg of hydrogen per hour and achieves a CO₂ reduction of 10416 tons/year. The wind farm (25 turbines) provides most of the energy at 396.7 dollars per hour while the gas turbine operates at 80% efficiency. By addressing the challenges of intermittent renewable energy in residential Zero-Energy Buildings this research offers a scalable and environmentally friendly solution contributing to sustainable urban living and advancing hydrogen energy applications.

The emergence and design of hydrogen transport infrastructures are crucial steps towards the development of a hydrogen economy. However pipeline routing remains underdeveloped in hydrogen infrastructure design models despite its significant impact on the resultant cost and network configuration. Many previous studies assume uniform cost surfaces on which pipelines are designed. Studies that consider a variable cost surface focus on designing candidate networks rather than bespoke routes for a given infrastructure. This study proposes a novel multi-stage approach based on a graph-based Steiner tree with Obstacles Genetic Algorithm (StObGA) to route pipelines on a complex cost surface for multi-source multi-sink hydrogen networks. The application of StObGA results in cost savings of 20–40% compared to alternative graph-based methods that assume uniform cost surfaces. Furthermore this publication presents an in-depth methodological comparative analysis of different pipeline routing and sizing methods used in the literature and discusses their impact. Finally we demonstrate how this model can generate design variations and provide practical insights to inform industry and policymakers.

In today’s world the need for sustainable energy solutions is paramount to address the ongoing crisis of increasing greenhouse gas emissions and global warming. Industries heavily reliant on fossil fuels must explore alternative energy sources. Hydrogen with its high heating value and zero direct emissions has emerged as a promising fuel for the future. Electrolytic hydrogen production has gained significance as it enables demand-side response grid stabilization using excess energy and the mitigation of curtailment from intermittent renewable energy sources (RES) such as solar and wind. Advanced combined heat and power (CHP) systems comprise of Solid oxide fuel cell (SOFC) module and a coupled reforming reactor to capture energy contained in the SOFC exhaust gases from SOFC. In present work 3D CFD model of an experimental coupled reactor used for onsite hydrogen production is developed and implemented into ANSYS Fluent® software. The study is aimed at opti mizing the reactor performance by identifying appropriate kinetic models for reforming and combustion re actions. SOFC anode off-gas (AOG) comprising mainly of unconverted hydrogen is combined with methane combustion to enhance thermal efficiency of the reactor and hence the CHP system. Kinetic models for catalytic reforming and combustion are implemented into ANSYS Fluent® through custom-built user defined functions (UDFs) written in C programming language. Simulation results are validated with experimental data and found in good agreement. AOG assisted combustion of methane shows a substantial improvement in thermal efficiency of the system. Improvement in thermal efficiency and reduction in carbon-based fuel demand AOG utilization contributes to sustainable hydrogen production and curtailment of greenhouse gas emissions.

Underground Hydrogen Storage (UHS) as an emerging large-scale energy storage technology has shown great promise to ensure energy security with minimized carbon emission. A set of comprehensive UHS site evaluation criteria based on important factors that affect UHS performances is needed for its potential commercialization. This study focuses on the UHS site evaluation of gas mixing. The economic implications of gas mixing between injected hydrogen gas and the residual or cushion gas in a porous storage reservoir is an emerging problem for Underground Hydrogen Storage (UHS). It is already clear that reservoir scale heterogeneity such as formation structure (e.g. formation dip angle) and facies heterogeneity of the sedimentary rock may considerably affect the reservoir-scale mechanical dispersion-induced gas mixing during UHS in high permeability braided-fluvial systems (a common depleted reservoir type for UHS). Following this finding the current study uses the processmimicking modeling software to build synthetic meandering-fluvial reservoir models. Channel dimensions and the presence of abandoned channel facies are set as testing parameters resulting in 4 simulation cases with 200 realizations. Numerical flow simulations are performed on these models to investigate and compare the effects of reservoir and metre-scale heterogeneity on UHS gas mixing. Through simulation channel dimensions (reservoir-scale heterogeneity) are found to affect the uncertainty of produced gas composition due to mixing (represented by the P10-P90 difference of hydrogen fraction in a produced stream) by up to 42%. The presence of abandoned channel facies (metre-scale heterogeneity) depending on their architectural relationship with meander belts could also influence the gas mixing process to a comparable extent (up to 40%). Moreover we show that there is no clear statistical correlation between gas mixing and typical reservoir characterization parameters such as original gas in place (OGIP) average reservoir permeability and the Dykstra-Parsons coefficient. Instead the average time of travel of all reservoir cells calculated from flow diagnostics shows a negative correlation with the level of gas mixing. These results reveal the importance of 3D reservoir architecture analysis (integration of multiple levels of heterogeneity) to UHS site evaluation on gas mixing in depleted gas reservoirs. This study herein provides valuable insights into UHS site evaluation regarding gas mixing.

Developing low-cost and high-performance transition metal-based electro-catalysts is crucial for realizing sustainable hydrogen evolution reaction (HER)in alkaline media. Here a cooperative boron and vanadium co-doped nickelphosphide electrode (B V-Ni2P) is developed to regulate the intrinsic elec-tronic configuration of Ni2P and promote HER processes. Experimental andtheoretical results reveal that V dopants in B V-Ni2P greatly facilitate the dis-sociation of water and the synergistic effect of B and V dopants promotes thesubsequent desorption of the adsorbed hydrogen intermediates. Benefitingfrom the cooperativity of both dopants the B V-Ni2P electrocatalyst requires alow overpotential of 148 mV to attain a current density of −100 mA cm−2 withexcellent durability. The B V-Ni2P is applied as the cathode in both alkalinewater electrolyzers (AWEs) and anion exchange membrane water electrolyzers(AEMWEs). Remarkably the AEMWE delivers a stable performance to achieve500 and 1000 mA cm−2 current densities at a cell voltage of 1.78 and 1.92 Vrespectively. Furthermore the developed AWEs and AEMWEs also demon-strate excellent performance for overall seawater electrolysis.

Hydrogen is viewed as a potential energy solution for the 21st century with capabilities to tackle issues relating to environmental emissions sustainability energy shortages and security. Even though there are potential benefits of renewable hydrogen towards transitioning to net-zero emissions there is a limited study on the current use ongoing development and future directions of renewable hydrogen in Australia. Thus this study conducts a systematic review of studies for exploring Australia’s renewable hydrogen energy transition current trends strategies developments and future directions. By using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines earlier studies from 2005 to 2024 from two major databases such as ProQuest and Web of Science are gathered and analyzed. The study highlights significant issues relating to hydrogen energy technologies and opportunities/challenges in production storage distribution utilization and environmental impacts. The study found that Australia’s ambition for a strong hydrogen economy is made apparent with its clear strategic actions to develop a clean technology-based hydrogen production storage and distribution system. This study provides several practical insights on Australia’s hydrogen energy transition hydrogen energy technologies investments and innovation as well as strategies/recommendations for achieving a more environment friendly secure affordable and sustainable energy future.

Green hydrogen is gaining prominence as a sustainable fuel to decarbonize hard-to-electrify industries and complement renewable energy growth. Among clean hydrogen production technologies seawater-based PEM electrolysis systems hold substantial promise. However implementing offshore PEM electrolysis systems faces significant challenges in ensuring long-term availability due to technological infancy and harsh environmental conditions. Ensuring safe and reliable operation is therefore critical to advancing global sustainability goals. While existing research has primarily focused on component-level techno-economic feasibility limited attention has been given to system-level safety and availability analysis particularly for offshore renewable-powered seawater-based PEM electrolysis systems. This study addresses this gap by conducting a comprehensive availability analysis of containerized plug-and-play PEM systems in offshore environments. A Bayesian Network model is employed incorporating Fault Tree Analysis and Reliability Block Diagram approaches for failure and availability analysis at the system level. A maintenance decision support tool using Influence diagram is developed to analyse different maintenance planning strategies impact on system availability improvement. A case study incorporating industrial modular PEM model is utilised to analyse the developed model effectiveness. The study identifies 81 availability states with the hydrogen generation subsystem being the most critical to system performance. Comparative analysis shows that applying redundancy across all subsystems improves availability by 18.54% but reduces Expected Utility by 4.94%. The optimal strategy involves redundancy for seawater purification cooling and monitoring subsystems with preventive maintenance for hydrogen generation achieving a maximum EU of 5.29 × 106. This framework supports decision-makers in evaluating system availability under uncertain offshore conditions optimizing maintenance strategies and ensuring resilience for large-scale H2 production.

The transition to sustainable energy has ushered in the era of electrofuels (e-fuels) which are synthesised using electricity from renewable sources water and CO2 as a sustainable alternative to fossil fuels. This paper presents a systematic review of the techno-economic (TEA) and life cycle assessments (LCAs) of e-fuel production. We critically evaluate advancements in production technologies economic feasibility environmental implications and potential societal impacts. Our findings indicate that while e-fuels offer a promising solution to reduce carbon emissions their economic viability depends on optimising production processes and reducing input material costs. The LCA highlights the necessity of using renewable energy for hydrogen production to ensure the genuine sustainability of e-fuels. This review also identifies knowledge gaps suggesting areas for future research and policy intervention. As the world moves toward a greener future understanding the holistic implications of e-fuels becomes paramount. This review aims to provide a comprehensive overview to guide stakeholders in their decision-making processes.

Countries around the world are prioritising net zero emissions to meet their Paris Agreement goals. The demand for social impact assessment (SIA) is likely to grow as this transition will require investments in decarbonisation projects with speed and at scale. There will be winners and losers of these projects because not everyone benefits the same; and hence trade-offs are inevitable. SIAs therefore should focus on understanding how the risks and benefits will be distributed among and within stakeholders and sectors and enable the identification of trade-offs that are just and fair. In this study we used a hypothetical case of large-scale hydrogen production in regional Australia and engaged with multi-disciplinary experts to identify justice issues in transitioning to such an industry. Using Rawlsian theory of justice as fairness we identified several tensions between different groups (national regional local inter and intra-communities) and sectors (environmental and economic) concerning the establishment of a hydrogen industry. These stakeholders and sectors will be disproportionately affected by this establishment. We argue that Rawlsian principles of justice would enable the practice of SIA to identify justice trade-offs. Further we conceptualise that a systems approach will be critical to facilitate a wider participation and an agile process for achieving just trade-offs in SIA.

This paper provides a comprehensive overview of the physical properties and applications of natural gas (NG) and hydrogen as fuels in internal combustion (IC) engines. The paper also meticulously examines the use of both NG and hydrogen as a fuel in vehicles their production physical characteristics and combustion properties. It reviews the current experimental studies in the literature and investigates the results of using both fuels. It further covers the challenges associated with injectors needle valves lubrication spark plugs and safety requirements for both fuels. Finally the challenges related to the storage production and safety of both fuels are also discussed. The literature review reveals that NG in spark ignition (SI) engines has a clear and direct positive impact on fuel economy and certain emissions notably reducing CO2 and non-methane hydrocarbons. However its effect on other emissions such as unburnt hydrocarbons (UHC) nitrogen oxides (NOx) and carbon monoxide (CO) is less clear. NG which is primarily methane has a lower carbon-to-hydrogen ratio than diesel fuel resulting in lower CO2 emissions per unit of energy released. In contrast hydrogen is particularly well-suited for use in gasoline engines due to its high self-ignition temperature. While increasing the hydrogen content of NG engines reduces torque and power output higher hydrogen input results in reduced fuel consumption and the mitigation of toxic exhaust emissions. Due to its high ignition temperature hydrogen is not inherently suitable for direct use in diesel engines necessitating the exploration of alternative methods for hydrogen introduction into the cylinder. The literature review suggests that hydrogen in diesel engines has shown a reduction in specific exhaust emissions and fuel consumption and an increase in NOx emissions. Overall the paper provides a valuable and informative overview of the challenges and opportunities associated with using hydrogen and NG as fuels in IC engines. It highlights the need for further research and development to address the remaining challenges such as the development of more efficient combustion chambers and the reduction of NOx emissions.

Hydrogen embrittlement in metals (HE) is a serious challenge for the use of high strength materials in engineering practice and a major barrier to the use of hydrogen for global decarbonization. Here we describe the factors and variables that determine HE susceptibility and provide an overview of the latest understanding of HE mechanisms. We discuss hydrogen uptake and how it can be managed. We summarize hydrogen trapping and the techniques used for its characterization. We also review literature that argues that hydrogen trapping can be used to decrease HE susceptibility. We discuss the future research that is required to advance the understanding of HE and hydrogen trapping and to develop HE-resistant alloys.