Australia

Hydrogen has emerged as a promising alternative to meet the growing demand for sustainable and renewable energy sources. Underground hydrogen storage (UHS) in depleted gas reservoirs holds significant potential for large-scale energy storage and the seamless integration of intermittent renewable energy sources due to its capacity to address challenges associated with the intermittent nature of renewable energy sources ensuring a steady and reliable energy supply. Leveraging the existing infrastructure and well-characterized geological formations depleted gas reservoirs offer an attractive option for large-scale hydrogen storage implementation. However significant knowledge gaps regarding storage performance hinder the commercialization of UHS operation. Hydrogen deliverability hydrogen trapping and the equation of state are key areas with limited understanding. This literature review critically analyzes and synthesizes existing research on hydrogen storage performance during underground storage in depleted gas reservoirs; it then provides a high-level risk assessment and an overview of the techno-economics of UHS. The significance of this review lies in its consolidation of current knowledge highlighting unresolved issues and proposing areas for future research. Addressing these gaps will advance hydrogen-based energy systems and support the transition to a sustainable energy landscape. Facilitating efficient and safe deployment of UHS in depleted gas reservoirs will assist in unlocking hydrogen’s full potential as a clean and renewable energy carrier. In addition this review aids policymakers and the scientific community in making informed decisions regarding hydrogen storage technologies.

Hydrogen embrittlement (HE) is a major concern when steel pipelines are used for hydrogen transportation and storage. The weldments of steel pipelines are of particular concern because they are reported to have higher HE susceptibility compare to the base metal. In this work targeted heat treatments were used to manipulate the microstructure in a pipeline steel weldment to examine the effects of different microstructural features on HE susceptibility. Complementary analyses of the microstructure mechanical testing and fracture surface identified inclusions and ferrite morphology as the most dominant microstructural features that affect the susceptibility to HE. Specimens with different microstructures but sharing similar Ti-rich inclusions exhibited significant re ductions in elongation to failure after hydrogen charging and showed brittle fracture surfaces decorated with multiple ‘fish-eye’ features. In addition co-existence of bainitic microstructure with Ti-rich inclusions resulted in the highest susceptibility to HE.

Supporters of hydrogen energy urge scaling up technology and reducing costs for competitiveness. This paper explores how hydrogen energy technologies (HET) are perceived by Australia’s general population and considers the way members of the public imagine their role in the implementation of hydrogen energy now and into the future. The study combines a nationally representative survey (n = 403) and semi-structured interviews (n = 30). Results show age and gender relationships with self-reported hydrogen knowledge. Half of the participants obtained hydrogen information from televised media. Strong support was observed for renewable hydrogen while coal (26%) and natural gas (41%) versions had less backing. Participants sought more safety-related information (41% expressed concern). Most felt uncertain about influencing hydrogen decisions and did not necessarily recognise they had agency beyond their front fence. Exploring the link between political identity and agency in energy decision-making is needed with energy democracy a potentially productive direction.

The optimization of hybrid renewable multi-generation systems is crucial for enhancing energy efficiency reducing costs and ensuring sustainable power generation. These factors can be significantly affected by system designs optimization methods climate changes and varying energy demands. The optimization of a stand-alone hybrid renewable energy system (HRES) that integrates various combinations of electricity heating cooling hydrogen and freshwater needs has not been reported in a single comprehensive study. Additionally there has been insufficient attention given to the impact of temporal resolution the recovery of excess energy usage and aligning these efforts with the sustainable development goals (SDGs). This study reviews the recent state-of-theart studies on the stand-alone HRES options for meeting electric heating cooling hydrogen electric vehicles and freshwater demands with various combinations. This study further contributes by examining contemporary literature on sizing optimization reliability analysis sensitivity analysis control techniques detailed modelling and techno-environmental-economic features. It also provides justification for selecting configurations suitable for specific geographical locations along with an analysis of the choice of algorithms and power management systems required to meet the various load demands of a self-sufficient community. By highlighting the im provements and potentials of HRES to achieve various United Nations SDGs this review study aims to bridge existing research gaps.

As the pursuit of greener energy solutions continues industries worldwide are turning away from fossil fuels and exploring the development of sustainable alternatives to meet their energy requirements. As a signatory to the Paris Agreement Australia has committed to reducing greenhouse gas emission by 43% by 2030 and reaching net-zero emissions by 2050. Australia’s domestic maritime sector should align with these targets. This paper aims to contribute to ongoing efforts to achieve these goals by examining the technical and commercial considerations involved in retrofitting conventional vessels with hydrogen power. This includes but is not limited to an analysis of cost risk and performance and compliance with classification society rules international codes and Australian regulations. This study was conducted using a small domestic commercial vessel as a reference to explore the feasibility of implementation of hydrogen-fuelled vessels (HFVs) across Australia. The findings indicate that Australia’s existing hydrogen infrastructure requires significant development for HFVs to meet the cost risk and performance benchmarks of conventional vessels. The case study identifies key determining factors for feasible hydrogen retrofitting and provides recommendations for the success criteria.

Hydrogen is the gas of the moment: an abundant element that can be created using renewable energy transported in gaseous or liquid form and offering the ability to provide energy with only water vapour as an emission. Hydrogen can also be used in a fuel blend in electricity generation gas turbines providing a low carbon option for providing the peak electricity to cover high demand and firming.<br/>While the electricity grid is itself transforming to decarbonising hard-to-abate industries such as cement and bauxite refineries are slower to reduce emissions constrained by their high temperature process requirements. Hydrogen offers a solution allowing onsite production process heat with waste heat recovery supporting blended gas turbine generation for onsite electricity supply.<br/>This article builds on decarbonisation pathway simulation results from an ANEM model of the electricity grid identifying the amount of peak demand energy required from gas turbines. The research then examines the quantity flow rate storage requirements and emissions reduction if this peak generation were supplied by open cycle hydrogen capable gas turbines.

Concerning the transition from a carbon-based energy economy to a renewable energy economy hydrogen is considered an essential energy carrier for efficient and broad energy systems in China in the near future. China aims to gradually replace fossil fuel-based power generation with renewable energy technologies to achieve carbon neutrality by 2060. This ambitious undertaking will involve building an industrial production chain spanning the production storage transportation and utilisation of hydrogen energy by 2030 (when China’s carbon peak will be reached). This review analyses the current status of technological R&D in China’s hydrogen energy industry. Based on published data in the open literature we compared the costs and carbon emissions for grey blue and green hydrogen production. The primary challenges concerning hydrogen transportation and storage are highlighted in this study. Given that primary carbon emissions in China are a result of power generation using fossil fuels we provide an overview of the advances in hydrogen-to-power industry technology R&D including hydrogen-related power generation technology hydrogen fuel cells hydrogen internal combustion engines hydrogen gas turbines and catalytic hydrogen combustion using liquid hydrogen carriers (e.g. ammonia methanol and ethanol).

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

This research conducted a probabilistic life-cycle assessment (pLCA) into the greenhouse gas (GHG) emissions performance of nine combinations of truck size and powertrain technology for a recent past and a future (largely decarbonised) situation in Australia. This study finds that the relative and absolute life-cycle GHG emissions performance strongly depends on the vehicle class powertrain and year of assessment. Life-cycle emission factor distributions vary substantially in their magnitude range and shape. Diesel trucks had lower life-cycle GHG emissions in 2019 than electric trucks (battery hydrogen fuel cell) mainly due to the high carbon-emission intensity of the Australian electricity grid (mainly coal) and hydrogen production (mainly through steam–methane reforming). The picture is however very different for a more decarbonised situation where battery electric trucks in particular provide deep reductions (about 75–85%) in life-cycle GHG emissions. Fuel-cell electric (hydrogen) trucks also provide substantial reductions (about 50–70%) but not as deep as those for battery electric trucks. Moreover hydrogen trucks exhibit the largest uncertainty in emissions performance which reflects the uncertainty and general lack of information for this technology. They therefore carry an elevated risk of not achieving the expected emission reductions. Battery electric trucks show the smallest (absolute) uncertainty which suggests that these trucks are expected to deliver the deepest and most robust emission reductions. Operational emissions (on-road driving and vehicle maintenance combined) dominate life-cycle emissions for all vehicle classes. Vehicle manufacturing and upstream emissions make a relatively small contribution to life-cycle emissions from diesel trucks (

Hydrogen has been studied extensively as a potential enabler of the energy transition from fossil fuels to renewable sources. It promises a feasible decarbonisation route because it can act as an energy carrier a heat source or a chemical reactant in industrial processes. Hydrogen can be produced via renewable energy sources such as solar hydro or geothermic routes and is a more stable energy carrier than intermittent renewable sources. If hydrogen can be stored efficiently it could play a crucial role in decarbonising industries. For hydrogen to be successfully implemented in industrial systems its impact on infrastructure needs to be understood quantified and controlled. If hydrogen technology is to be economically feasible we need to investigate and understand the retrofitting of current industrial infrastructure. Currently there is a lack of comprehensive knowledge regarding alloys and components performance in long-term hydrogen-containing environments at industrial conditions associated with high-temperature hydrogen processing/production. This review summarises insights into the gaps in hydrogen embrittlement (HE) research that apply to high-temperature high-pressure systems in industrial processes and applications. It illustrates why it is still important to develop characterisation techniques and methods for hydrogen interaction with metals and surfaces under these conditions. The review also describes the implications of using hydrogen in large-scale industrial processes.

One of the benefits of the direct use of hydrogen is its ability to be burned in a similar way to natural gas using appliances with which the community is already familiar. This is particularly true for applications where electrification is neither practicable nor desirable. One common example is domestic cooking stoves where the open flame offers numerous real and perceived benefits to the chef. Similarly many commercial and industrial appliances rely on the unique properties of combustion to achieve a desired purpose that cannot readily be replaced by an alternative to an open flame. Despite the enormous decarbonisation potential of the direct replacement of natural gas with hydrogen there are some operational constraints due to the different burning characteristics of hydrogen. One of the challenges is the low visible light emission from hydrogen flames. The change in visible radiation from the combustion of hydrogen compared with natural gas is a safety concern whereby visual observation of a flame may be difficult. This paper aims to provide clarity on the visual appearance of hydrogen flames via a series of measurements of flame visibility and emission spectra accompanied by the assessment of strategies to improve the safe use of hydrogen.

In this work we examine the possibility of converting a light propeller-driven aircraft powered by a spark-ignition reciprocating piston and internal combustion engine running on AVGAS into one powered by an electric motor driven by a proton exchange membrane fuel cell stack running on hydrogen. Our studies suggest that storing hydrogen cryogenically is a better option than storing hydrogen under pressure. In comparison to cryogenic tanks high-pressure tanks are extremely heavy and unacceptable for light aircraft. We show that the modified aircraft (including batteries) is no heavier than the original and that the layout of the major components results in lower movement of the aircraft center-of-gravity as the aircraft consumes hydrogen. However we acknowledge that our fuel cell aircraft cannot store the same amount of energy as the original running on AVGAS. Therefore despite the fact that the fuel cell stack is markedly more efficient than an internal combustion engine there is a reduction in the range of the fuel cell aircraft. One of our most important findings is that the quantity of energy that we need to dissipate to the surroundings via heat transfer is significantly greater from a fuel cell stack than from an internal combustion engine. This is particularly the case when we attempt to run the fuel cell stack at high current densities. To control this problem our strategy during the cruise phase is to run the fuel cell stack at its maximum efficiency where the current density is low. We size the fuel cell stack to produce at least enough power for cruise and when we require excess power we add the energy stored in batteries to make up the difference.

Hydrogen embrittlement (HE) poses a significant challenge for high-strength steels. Although HE of wrought steels has been extensively studied it remains limited in steels processed by additive manufacturing (AM). The present work (i) compares the HE susceptibility of AISI 4340 ultra-high-strength steel fabricated by selective laser melting (SLM) with its wrought counterpart; (ii) investigates the predominant factors and possible HE mechanisms in the AM-fabricated material; and (iii) correlates microstructures produced with different SLM processing parameters to HE susceptibility of the steel. Generally conventionally processed AISI 4340 steel is used with a tempered martensitic structure to ensure the ultrahigh strength and therefore is susceptible to HE. In contrast SLM-fabricated 4340 exhibits a uniform refined bainitic microstructure. How this change of microstructure influences the HE susceptibility of the steel is unknown and needs investigation. Our results demonstrate that at the same level of strength the SLM-fabricated 4340 steel exhibits significantly lower HE susceptibility than its wrought counterpart. The SLM-fabricated steel showed a higher hydrogen diffusion rate. Furthermore the refined microstructure of the SLM-fabricated steel contributes to enhanced ductility even with hydrogen. These findings indicate that AM of high-strength steels has strong potential to improve HE resistance providing a pathway to solve this long-term problem. This study highlights the critical role of microstructure in influencing HE and offers valuable insights for developing steels for hydrogen applications.

In this article we draw on findings from a mixed-methods international survey of experts in the energy sector (n = 179) to better understand the role of legitimacy theory in informing the development of renewable hydrogen standards certification and labelling (SCL). The investigation is viewed through two conceptions of legitimacy: the sociological legitimacy of increasing the availability of renewable hydrogen technologies and the normative legitimacy of democratic SCL governance. Results revealed that respondents reacted positively to survey state ments representing sociological legitimacy whereas qualitative data exposed some concerns with pragmatic and cognitive legitimacy such as a lack of immediate benefits and poor comprehensibility stemming from sources including economics and energy strategy. Respondents' ratings of the democratic legitimacy of hydrogen SCLs indicated inputs were perceived to have the most legitimacy followed by throughputs then outputs. The analysis revealed some evidence that features of scheme design and governance may influence experts' evaluations of schemes. Moreover results indicated an opportunity to increase awareness and knowledge of SCLs within the expert community and societally. This study provides evidence to support the premise that hydrogen SCLs would benefit from pursuing diversity in stakeholder participation enhancing process transparency and judging the efficacy of outputs against both decarbonisation and sustainability goals. Attention to these democratic factors among others would enhance the capacity of SCLs to contribute to the sociological legitimation of renewable hydrogen technologies.

The existing gas transmission pipeline network can be a convenient and cost-effective way to transport hydrogen. However hydrogen can cause hydrogen embrittlement (HE) of the steels used in pipeline construction. HE is typically manifested as a reduction in fracture toughness and ductility. To ensure structural integrity it is thus important to understand the fracture toughness of pipeline steels in hydrogen gas at pipeline pressures. This paper reviews (i) the influence of hydrogen on the fracture toughness of pipeline steels and (ii) the phenomena that occurs during fracture toughness tests of pipeline steel in air and hydrogen. Also reviewed are (i) the in fluence of hydrogen on tensile properties and (ii) the diffusion and solubility of hydrogen in pipeline steels under conditions relevant to hydrogen transport in gas transmission pipelines.

The commercialization of hydrogen as a fuel faces severe technological economic and environmental challenges. As a method to overcome these challenges microalgal biohydrogen production has become the subject of growing research interest. Microalgal biohydrogen can be produced through different metabolic routes the economic considerations of which are largely missing from recent reviews. Thus this review briefly explains the techniques and economics associated with enhancing microalgae-based biohydrogen production. The cost of producing biohydrogen has been estimated to be between $10 GJ-1 and $20 GJ−1 which is not competitive with gasoline ($0.33 GJ−1 ). Even though direct biophotolysis has a sunlight conversion efficiency of over 80% its productivity is sensitive to oxygen and sunlight availability. While the electrochemical processes produce the highest biohydrogen (>90%) fermentation and photobiological processes are more environmentally sustainable. Studies have revealed that the cost of producing biohydrogen is quite high ranging between $2.13 kg−1 and 7.24 kg−1 via direct biophotolysis $1.42kg−1 through indirect biophotolysis and between $7.54 kg−1 and 7.61 kg−1 via fermentation. Therefore low-cost hydrogen production technologies need to be developed to ensure long-term sustainability which requires the optimization of critical experimental parameters microalgal metabolic engineering and genetic modification.

Hydrogen is considered as a promising fuel in the 21st century due to zero tailpipe CO2 emissions from hydrogen-powered vehicles. The use of hydrogen as fuel in vehicles can play an important role in decarbonising the transport sector and achieving net-zero emissions targets. However there exist several issues related to hydrogen production efficient hydrogen storage system and transport and refuelling infrastructure where the current research is focussing on. This study critically reviews and analyses the recent technological advancements of hydrogen production storage and distribution technologies along with their cost and associated greenhouse gas emissions. This paper also comprehensively discusses the hydrogen refuelling methods identifies issues associated with fast refuelling and explores the control strategies. Additionally it explains various standard protocols in relation to safe and efficient refuelling analyses economic aspects and presents the recent technological advancements related to refuelling infrastructure. This study suggests that the production cost of hydrogen significantly varies from one technology to others. The current hydrogen production cost from fossil sources using the most established technologies were estimated at about $0.8–$3.5/kg H2 depending on the country of production. The underground storage technology exhibited the lowest storage cost followed by compressed hydrogen and liquid hydrogen storage. The levelised cost of the refuelling station was reported to be about $1.5–$8/kg H2 depending on the station's capacity and country. Using portable refuelling stations were identified as a promising option in many countries for small fleet size low-to-medium duty vehicles. Following the current research progresses this paper in the end identifies knowledge gaps and thereby presents future research directions.

With the question of ‘can short messages be effective in increasing public support for a complex new technology (hydrogen)?‘ this study uses a representative national survey in Australia to analyze the differences and variations in subjective support for hydrogen in response to four differently framed short messages. The findings of this study show that short messages can increase social acceptance but the effects depend on how strongly the message is framed in terms of its alignment with either an economic or environmental values framework. Furthermore the effects depend on the social and cultural context of the receiver of the message.

The inherent intermittency of upstream solar and wind power can result in fluctuating electrolytic hydrogen production which is incompatible with the feedstock requirements of many downstream hydrogen storage and utilisation applications. Suitable backup power or storage (hydrogen or energy) strategies are thus needed in overall system design. This work conducts technoeconomic modelling to design electrolytic production systems featuring stable hydrogen output for various locations across Australia based on hourly weather data and determines the levelised cost of hydrogen (LCOH) emissions intensities and annual electrolyser usage factors. A stable truly green hydrogen supply is consistently achieved by imposing annual usage factor requirements on the system which forces the system modules (i.e. solar wind electrolyser and hydrogen storage) to be oversized in order to achieve the desired usage factor. Whilst the resultant system designs are however very location-specific a design that ensures a 100% usage factor costs approximately 22% more on average than a system design which is optimised for cost alone.

This study presents a technoeconomic analysis of renewables-based hydrogen production in Queensland Australia under Optimistic Reference and Pessimistic scenarios to address uncertainty in cost predictions. The goal of the work was to ascertain if the target fam-gate cost of AUD 3/kg (approx. USD 2/kg) could be reached. Economies of scale and the learning rate concept were factored into the economic model to account for the effect of scale-up and cost reductions as electrolyser manufacturing capacity grows. The model assumes that small-scale to large-scale wind turbine (WT)-based and photovoltaic (PV)-based power generation plants are directly coupled with an electrolyser array and utilises hourly generation data for the Gladstone hydrogen-hub region. Employing first a commonly used simplified approach the electrolyser array was sized based on the maximum hourly power available for hydrogen production. The initial results indicated that scale-up is very beneficial: the levelised cost of green hydrogen (LCOH) could decrease by 49% from $6.1/kg to $3.1/kg when scaling PV-based plant from 10 MW to 1 GW and for WT-based plant by 36% from $5.8/kg to $3.7/kg. Then impacts on the LCOH of incorporating curtailment of ineffective peak power and electrolyser overload capacity were investigated and shown to be significant. Also significant was the beneficial effect of recognising that electrolyser efficiency depends on input power. The latter two factors have mostly been overlooked in the literature. Incorporating in the model the influence on the LCOH of real-world electrolyser operational characteristics overcomes a shortcoming of the simplified sizing method namely that a large portion of electrolyser capacity is under-utilised leading to unnecessarily high values of the LCOH. It was found that AUD 3/kg is achievable if the electrolyser array is properly sized which should help to incentivise large-scale renewable hydrogen projects in Australia and elsewhere.

Fuel cell electric vehicles (FCEVs) have received significant attention in recent times due to various advantageous features such as high energy efficiency zero emissions and extended driving range. However FCEVs have some drawbacks including high production costs; limited hydrogen refueling infrastructure; and the complexity of converters controllers and method execution. To address these challenges smart energy management involving appropriate converters controllers intelligent algorithms and optimizations is essential for enhancing the effectiveness of FCEVs towards sustainable transportation. Therefore this paper presents emerging energy management strategies for FCEVs to improve energy efficiency system reliability and overall performance. In this context a comprehensive analytical assessment is conducted to examine several factors including research trends types of publications citation analysis keyword occurrences collaborations influential authors and the countries conducting research in this area. Moreover emerging energy management schemes are investigated with a focus on intelligent algorithms optimization techniques and control strategies highlighting contributions key findings issues and research gaps. Furthermore the state-of-the-art research domains of FCEVs are thoroughly discussed in order to explore various research domains relevant outcomes and existing challenges. Additionally this paper addresses open issues and challenges and offers valuable future research opportunities for advancing FCEVs emphasizing the importance of suitable algorithms controllers and optimization techniques to enhance their performance. The outcomes and key findings of this review will be helpful for researchers and automotive engineers in developing advanced methods control schemes and optimization strategies for FCEVs towards greener transportation.

There is growing interest in using hydrogen (H2) as a marine fuel. Fire and explosion risks depend on hydrogen release and dispersion characteristics. Based on a validated Computational Fluid Dynamics (CFD) model this study performed hydrogen release and dispersion analysis on an under-deck compressed H2 storage system for a Live-Fish Carrier. A realistic under-deck H2 storage room was modelled based on the ship’s main dimensions and operational profile. Det Norske Veritas (DNV) Rules and Regulations for natural gas storage as a marine fuel were employed as base design guidelines. Case studies were developed to study the effect of two ceiling types (flat and slanted) in terms of flammable cloud formation and dissipation. During the leak’s duration it was found that the recommended ventilation rate was insufficient to dilute the average H2 concentration below 25% of the flammable range as required by DNV (1.2% required against 1.3% slanted and 1.4% flat). However after 35 s of gas extraction the H2 concentration was reduced to 0.5% and 0.6% in the slanted and flat cases respectively. The proposed methodology remains valid to improve the ventilation system and assess mitigation alternatives or other leakage scenarios in confined or semi-confined spaces containing compressed hydrogen gas.

This paper presents the “Three Gorges Hydrogen Boat No. 1” a novel green hydrogen-powered vessel that has been successfully delivered and is currently sailing. This vessel integrated with a hydrogen production and bunkering station at its dedicated dock achieves zero-carbon emissions. It stores 240 kg of 35 MPa gaseous hydrogen and has a fuel cell system rated at 500 kW. We analysed the engineering details of the marine hydrogen system including hydrogen bunkering storage supply fuel cell and the hybrid power system with lithium-ion batteries. In the first bunkering trial the vessel was safely refuelled with 200 kg of gaseous hydrogen in 156 min via a bunkering station 13 m above the water surface. The maximum hydrogen pressure and temperature recorded during bunkering were 35.05 MPa and 39.04 ◦C respectively demonstrating safe and reliable shore-toship bunkering. For the sea trial the marine hydrogen system operated successfully during a 3-h voyage achieving a maximum speed of 28.15 km/h (15.2 knots) at rated propulsion power. The vessel exhibited minimal noise and vibration and its dynamic response met load change requirements. To prevent rapid load changes to the fuel cells 68 s were used to reach 483 kW from startup and 62 s from 480 kW to zero. The successful bunkering and operation of this hydrogen-powered vessel demonstrates the feasibility of zero-carbon emission maritime transport. However four lessons were identified concerning bunkering speed hydrogen cylinder leakage hydrogen pressure regulator malfunctions and fuel cell room space. The novelty of this work lies in the practical demonstration of a fully operational hydrogen-powered maritime vessel achieving zero emissions encompassing its design building operation and lessons learned. These parameters and findings can be used as a baseline for further engineering research.

Hydrogen produced from renewable energy is being promoted to decarbonise global energy systems. To support this energy transition standards certification and labelling schemes (SCLs) aim to differentiate hydrogen products based on their system-wide carbon emissions and method of production characteristics. However being certified as low-carbon clean or green hydrogen does not guarantee broader sustainability across economic environmental social or governance dimensions. Through an international survey of energy-sector and sustainability professionals (n = 179) we investigated the desirable sustainability features for renewable hydrogen SCLs and the perceived advantages and disadvantages of sustainability certification. Our mixed-method study revealed general accordance on the feasible inclusion of diverse sustainability criteria in SCLs albeit with varying degrees of perceived essentiality. Within the confines of the data some differences in viewpoints emerged based on respondents’ geographical and supply chain locations which were associated with the sharing of costs and benefits. Qualitatively respondents found the idea of SCL harmonisation attractive but weighed this against the risks of duplication complicated administrative procedures and contradictory regulation. The implications of this research centre on the need for further studies to inform policy recommendations for an overarching SCL sustainability framework that embodies the principles of harmonisation in the context of multistakeholder governance.

Growth in Australia’s demand for engineers is fast outpacing supply. A significant challenge for Australia to achieve high projected low emissions hydrogen export targets by 2030 will be finding engineers with suitable knowledge skills and attributes to deliver hydrogen engineering projects safely and sustainably. This systematic review investigates educational outcomes needed to develop a hydrogen engineering workforce. Sixteen relevant studies published between 2003 and 2023 were identified to explore “What key knowledge skills and attributes support the development of a hydrogen engineering workforce?”. While these studies advocated the need for training and prescribed areas of required knowledge for the low-emissions hydrogen sector there was limited empirical evidence that informed what knowledge skills and attributes are relevant for entry to practice. This finding represents a significant opportunity for researchers to engage with employers and engineering practitioners within emerging low-emissions hydrogen sector capture empirical evidence and inform the design of educational programs.