Applications & Pathways

This article examines the growing potential of low-emission hydrogen as an innovative solution supporting the decarbonization of the agricultural sector. It discusses its potential applications on farms including as an energy source for powering agricultural machinery producing fertilizers and storing energy from renewable sources. Within the European context it considers actions arising from the European Green Deal and the “Fit for 55” strategy which promote the development of hydrogen infrastructure and support research into low-emission technologies. The article also discusses global initiatives and trends in the development of the hydrogen economy pointing to international cooperation investment and the need for technology standardization. It highlights the challenges related to cost infrastructure and scalability as well as the opportunities hydrogen offers for a sustainable and energy-efficient agriculture of the future.

The power-to-methanol (PtMeOH) will play a crucial role as a form of renewable chemical energy storage. In this paper PtMeOH techno-economics are assessed using the promising configuration from the previous work (Mbatha et al. [1]). This study evaluated the effect of parameters such as the CO2 emission tax electricity price and CAPEX reduction on the product methanol economic parity with respect to a reference case. Superior to previous economic studies a scenario where an existing methanol synthesis infrastructure is 100 % retrofitted with the promising electrolyser is assessed in terms of its economics and the associated economic parity. The volatile South African electricity market is considered as a case study. The sensitivity of the PtMeOH and green H2 profitability are checked. Grid-connected and standalone renewable energy PtMeOH scenarios are assessed. Foremost generalisable effect trends of these parameters on the net present value (NPV) and the levelized cost of methanol(LCOMeOH) and H2 (LCOH2) are discussed. The results show that economic parity of H2 (LCOH2 = current selling price = 4.06 €/kg) can be reached with an electricity price of 30 €/MWh and 70 % of the CAPEX. While the LCOMeOH will still be above 2 €/kg at 80 % of the CAPEX and electricity price of 20 €/MWh. This indicates that even if the CAPEX reduces to 20 % of its original in this study and the electricity price reduces to about 20 €/MWh the LCOMEOH will still not reach economic parity (LCOMeOH > current selling price = 0.44 €/kg). The results show that to make the retrofitted plant with a minimum of 20 years of life span profitable a feasible reduction in the electricity price to below 10 €/MWh along with favourable incentives such as CO2 credit and reduction in CAPEX particularly that of the electrolyser and treatment of the PtMeOH as a multiproduct plant will be required.

In the context of renewable energy systems microgrids (MG) are a solution to enhance the reliability of power systems. In the last few years there has been a growing use of energy storage systems (ESSs) such as hydrogen and battery storage systems because of their environmentally-friendly nature as power converter devices. However their short lifespan represents a major challenge to their commercialization on a large scale. To address this issue the control strategy proposed in this paper includes cost functions that consider the degradation of both hydrogen devices and batteries. Moreover the proposed controller uses scenarios to reflect the stochastic nature of renewable energy resources (RESs) and load demand. The objective of this paper is to integrate a stochastic model predictive control (SMPC) strategy for an economical/environmental MG coupled with hydrogen and battery ESSs which interacts with the main grid and external consumers. The system's participation in the electricity market is also managed. Numerical analyses are conducted using RESs profiles and spot prices of solar panels and wind farms in Abu Dhabi UAE to demonstrate the effectiveness of the proposed controller in the presence of uncertainties. Based on the results the developed control has been proven to effectively manage the integrated system by meeting overall constraints and energy demands while also reducing the operational cost of hydrogen devices and extending battery lifetime.

For centuries fossil fuels have been the primary energy source but their unchecked use has led to significant environmental and economic challenges that now shape the global energy landscape. The combustion of these fuels releases greenhouse gases which are critical contributors to the acceleration of climate change resulting in severe consequences for both the environment and human health. Therefore this article examines the potential of hydrogen as a sustainable alternative energy source capable of mitigating these climate impacts. It explores the properties of hydrogen with particular emphasis on its application in industrial burners and furnaces underscoring its clean combustion and high energy density in comparison to fossil fuels and also examines hydrogen production through thermochemical and electrochemical methods covering green gray blue and turquoise pathways. It discusses storage and transportation challenges highlighting methods like compression liquefaction chemical carriers (e.g. ammonia) and transport via pipelines and vehicles. Hydrogen combustion mechanisms and optimized burner and furnace designs are explored along with the environmental benefits of lower emissions contrasted with economic concerns like production and infrastructure costs. Additionally industrial and energy applications safety concerns and the challenges of large-scale adoption are addressed presenting hydrogen as a promising yet complex alternative to fossil fuels.

Hydrogen price significantly impacts its potential as a viable alternative in the sustainable energy transition. This study introduces a synergy-based Hydrogen Pricing Mechanism (HPM) within an integrated framework. The HPM leverages synergy between a Renewable-Penetrated Electric Power System (RP-EPS) and a Hydrogen Energy System (HES). Utilizing the Alternating Direction Method of Multipliers (ADMM) it facilitates data exchange quantifying integration levels and simplifying the complexities. The study assesses the HPM’s operational sensitivity across various scenarios of hydrogen generation transportation and storage. It also evaluates the benefits of synergy-based versus stand-alone HPMs. Findings indicate that the synergy-based HPM effectively integrates infrastructure and operational improvements from both EPS and HES leading to optimized hydrogen pricing.

The transition from traditional petrol-based combustion engines to hydrogen-powered systems represents a promising advancement in sustainable and clean energy solutions. This review paper explores the intricacies of converting a conventional internal combustion engine to operate on hydrogen gas. Key topics include the performance limitations of hydrogen engines the role of water injection in combustion modulation and the investigation of direct injection and port injection systems. This review also examines challenges associated with lean and rich mixtures risks of backfire and pre-ignition and the conversion’s overall impact on engine performance and longevity. Additionally this paper discusses hydrogen lubrication to prevent mechanical wear and addresses emission-related considerations.

Hydrogen valleys are encompassed within a defined geographical region with various technologies across the entire hydrogen value chain. The scope of this study is to analyze and assess the different hydrogen technologies for their application within the hydrogen valley context. Emphasizing on the coupling of renewable energy sources with electrolyzers to produce green hydrogen this study is focused on the most prominent electrolysis technologies including alkaline proton exchange membrane and solid oxide electrolysis. Moreover challenges related to hydrogen storage are explored alongside discussions on physical and chemical storage methods such as gaseous or liquid storage methanol ammonia and liquid organic hydrogen carriers. This article also addresses the distribution of hydrogen within valley operations especially regarding the current status on pipeline and truck transportation methods. Furthermore the diverse applications of hydrogen in the mobility industrial and energy sectors are presented showcasing its potential to integrate renewable energy into hard-to-abate sectors.

Hydrogen (H2) offers a green medium for storing the excess from renewables production instead of dumping it thus being crucial to decarbonisation efforts. Hydrogen also offers a storage medium for the grid’s cheap electricity to be used during grid peak demand or grid power cutoffs. Funded by the Scottish Government’s Emerging Energy Technologies this paper presents the design and performance analysis of a hydrogen uninterruptible power supply (H2GEN) for Cygnas Solutions Ltd. which is intended to enable continuity of supply in the residential sector while eradicating the need for environmentally and health risky lead–acid batteries and diesel generator backup. This paper presents the design optimal sizing and analysis of two H2Gen architectures one powered by the grid alone and the other powered by both the grid and a renewable (PV) source. By developing a model of each architecture in the HOMER space and using residential location weather data the home yearly load–demand profile and the grid yearly power outages profile in the developed models the optimal sizing of each H2Gen design was realised by minimising the costs while ensuring the H2Gen meets the home power demand during grid outages To enable HOMER to optimise its selection the sizes technical specifications and costs of all the market-available H2GEN components were added in the HOMER search space. Moreover the developed models were also used in assessing the sensitivity of the simulation outputs to several changes in the modelled system design and settings. Using a residential home with frequent power outages in New Delhi India as a case study it was found that the optimal sizing of H2Gen Architecture 1 is comprised of a 2 kW electrolyser a 0.2 kg type-I tank and a 2 kW water-cooled fuel cell directly connected to the AC bus offering an operational lifetime of 14.3 years. It was also found that the optimal sizing of Architecture 2 is comprised of a 1 kV PV utilised with the same 2 kW electrolyser 0.2 kg type-I tank and 2 kW water-cooled fuel cell connected to the AC bus. While the second design was found to have a higher capital cost due to the added PV it offered a more cost-effective and environmentally friendly architecture which contributes to the ongoing energy transition. This paper further investigated the capacity expansion of each H2GEN architecture to meet higher load demands or increased grid power outages. From the analysis of the simulation results it has been concluded that the most feasible and cost-effective H2GEN system expansion for meeting increased power demands or increased grid outages can be realised by using the developed models for optimally sizing the expanded H2Gen on a case-by-case basis because the increase in these profiles is highly time-dependent (for example an increased load demand or increased grid outage in the morning can be met by the PV while in the evening it must be met by the H2GEN). Finally this paper investigated the impact of other environmental variables such as the temperature and relative humidity on the H2GEN’s performance and provided further insights into increasing the overall system efficiency and cost benefit through utilising the H2GEN’s exhaust heat in the home space for heating/cooling and selling the electrolyser exhaust’s O2 as a commodity.

To reduce carbon dioxide emissions from the steel industry efforts are made to introduce a steelmaking route based on hydrogen reduction of iron ore instead of the commonly used cokebased reduction in a blast furnace. Changing fundamental pieces of steelworks affects the functions of most every system unit involved and thus warrants the question of how such a transition could optimally take place over time and no rigorous attempts have until now been made to tackle this problem mathematically. This article presents a steel plant optimization model written as a mixed-integer non-linear programming problem where aging blast furnaces and basic oxygen furnaces could potentially be replaced with shaft furnaces and electric arc furnaces minimizing costs or emissions over a long-term time horizon to identify possible transition pathways. Example cases show how various parameters affect optimal investment pathways stressing the necessity of appropriate planning tools for analyzing diverse cases.

Fuel cell electric vehicles are getting deployed exponentially in Europe. Hydrogen fuel quality regulations are getting into place in order to protect customers and ensure end-users satisfactory experiences. It became critical to have the capability to sample and analyse accurately hydrogen fuel delivered by hydrogen refuelling stations in Europe. This study presents two separate comparisons: the first bilateral comparison between two sampling systems (H2 Qualitizer) and (“H2 Sampling System” of Air Liquide) and the interlaboratory comparison between NPL and Air Liquide on hydrogen fuel quality testing according to EN 17124. The two sampling systems showed equivalent results for all contaminants for sampling at 70 MPa hydrogen refuelling stations. The two laboratories showed good agreement at 95% confidence level. Even if the study is limited due to the low number of samples it demonstrates the equivalence of two sampling strategies and the ability of two laboratories to perform accurate measurement of hydrogen fuel quality.

This paper aims at the development and validation of a computational fluid dynamic (CFD) model for simulations of the refuelling process through the entire equipment of the hydrogen refuelling station (HRS). The absence of such models hinders the design of inherently safer refuelling protocols for an arbitrary combination of HRS equipment hydrogen storage parameters and environmental conditions. The CFD model is validated against the complete process of refuelling lasting 195s in Test No.1 performed by the National Renewable Energy Laboratory (NREL). The test equipment includes high-pressure tanks of HRS pressure control valve (PCV) valves pipes breakaway hose and nozzle all the way up to three onboard tanks. The model accurately reproduced hydrogen temperature and pressure through the entire line of HRS equipment. A standout feature of the CFD model distinguishing it from simplified models is the capability to predict temperature non-uniformity in onboard tanks a crucial factor with significant safety implications.

Optimal design and performance analysis of renewable energy system to serve the cruise ship main and auxiliary power in Stockholm Sweden is presented in this paper. The goal is to integrate renewable energy systems in small and large ships for greener and sustainable marine transport. The power load for the cruise ship was determined and modeling and simulation analysis was used to investigate the daily and annual performance of the power system architectures including the efficiency and capacity factors of the energy conversion systems. The total electrical power generated from the solar PV PEM fuel cell and Diesel generator; the cost of electricity; and the greenhouse gas and particulate matter PM emissions were determined. The proposed renewable energy system offers a good penetration of renewable energy system (13.83%) and greenhouse gas and particulate emissions reduction (9.84% emissions reduction compared to baseline system using Diesel engines). The integration of renewable and clean power systems such as solar PV and PEM fuel cell (high electrical efficiency) is very attractive solution for onboard ship power generation. They are economically viable (reduce the cost of Diesel fuel) cleaner than the conventional gas turbine and internal combustion engines and reduce the dependency on fossil fuel.

Nowadays integrating renewable energy sources (RESs) poses significant challenges due to the deterioration of performance indices especially in cold-climate unbalanced microgrids. Beyond network unbalance harsh conditions with low irradiance weak wind speeds and low temperatures necessitate hydrogen storage systems (HSSs) to address seasonal mismatches between RES generation and demand. This paper proposes a two-stage multi-timescale planning framework that integrates RESs plug-in electric vehicles (PEVs) battery energy storage systems (BESSs) seasonal HSSs and a dynamic demand response (DDR) program. In the short term BESSs are coordinated under slow and fast charging/discharging modes for responding to daily load shifting and peak shaving or sudden demand fluctuations. Smart converters with active/reactive power control are equipped with RES and BESS for local voltage regulation. Furthermore the proposed DDR program which combines load reduction and valley filling strategies enables consumer flexibility based on real-time market signals across seasonal variations. Seasonal HSSs are designed to store excess hydrogen produced from RESs for long-term use across different seasons. The proposed strategy is validated in two stages. The first stage guarantees multitimescale coordination of BESSs seasonal HSSs and the DDR. In turn the second stage optimally plans RESs BESSs and HSSs in a unified manner to reduce voltage unbalance and line congestion while maximizing microgrid RES hosting capacity. Simulation results for six interconnected microgrids demonstrate a 12.5% reduction in voltage unbalance 21% alleviation of line congestion and a 108% increase in hosting capacity highlighting the effectiveness of the proposed planning approach for unbalanced RES-rich microgrids.

Hydrogen fuel cell electric trucks and battery electric trucks can significantly contribute to the decarbonisation of the heavy-duty vehicles transport segment. Nonetheless a paucity of hydrogen refuelling and fast-charging stations can represent a hindrance to the development of zero-emission vehicles. This work aims to provide a techno-economic analysis with a view to comparing the costs of hydrogen refuelling and electric charging and evaluating their effects on the total cost of ownership of zero-emission trucks. Thus a comprehensive analysis has been conducted on off-site compressed (CH2) cryo-compressed subcooled hydrogen refuelling stations in conjunction with a fast-charging station. The resulting levelized costs of hydrogen and charging have been incorporated into the total cost of ownership analysis. Thus it has been demonstrated that battery electric trucks are more costeffective than hydrogen-fuel cell electric trucks. The findings of this study indicate that the costs associated with electric charging and hydrogen refuelling are comparable and the economic profitability is contingent upon a number of techno-economic variables. Therefore it is not possible to determine a priori whether one solution is more economically competitive than the other. A mixed infrastructure can represent an opportunity for the transport sector decarbonisation whereby electric-charging and hydrogen-refuelling are not mutually exclusive.

Proton exchange membrane fuel cells (PEMFCs) present great potential for the decarbonization of the maritime sector but their durability in harsh marine environments remains a critical challenge. This review focuses on post-mortem analysis techniques as a tool to understand the degradation mechanisms of PEMFCs under stressors relevant to marine applications. In further detail the application of various imaging (SEM TEM) structural (XRD) electrochemical (CV) and elemental analysis (EDS) methods to characterize the effects of key stressors such as salt spray mechanical vibration and operational cycling was examined. By analyzing degraded PEMFC components post-mortem analysis reveals critical insights into catalyst layer degradation membrane damage and the impact of impurities enabling the identification of failure modes and the development of effective mitigation strategies for the establishment of PEMFCs in the maritime sector.

This work aims to study the technical and economical feasibility of a new hydrogen transport network by 2035 in France. The goal is to furnish charging stations for fuel cell electrical vehicles with hydrogen produced by electrolysis of water using low-carbon energy. Contrary to previous research works on hydrogen transport for road transport we assume a more realistic assumption of the demand side: we assume that only drivers driving more than 20000 km per year will switch to fuel cell electrical vehicles. This corresponds to a total demand of 100 TWh of electricity for the production of hydrogen by electrolysis. To meet this demand we primarily use surplus electricity production from wind power. This surplus will satisfy approximately 10% of the demand. We assume that the rest of the demand will be produced using surplus from nuclear power plants disseminated in regions. We also assume a decentralized production namely that 100 MW electrolyzers will be placed near electricity production plants. Using an optimization model we define the hydrogen transport network by considering decentralized production. Then we compare it with more centralized production. Our main conclusion is that decentralized production makes it possible to significantly reduce distribution costs particularly due to significantly shorter transport distances.

The fuel cell electric vehicle (FCEV) is a promising transportation technology for resolving the air pollution and climate change issues in the United States. However a large-scale penetration of FCEVs would require a sustained supply of hydrogen which does not exist now. Water electrolysis can produce hydrogen reliably and sustainably if the electricity grid is clean but the impacts of FCEVs on the electricity grid are unknown. In this paper we develop a comprehensive framework to model FCEV-driving and -refueling behaviors the water electrolysis process and electricity grid operation. We chose the Western Electricity Coordinating Council (WECC) region for this case study. We modeled the existing WECC electricity grids and accounted for the additional electricity loads from FCEVs using a Production Cost Model (PCM). Additionally the hydrogen need for five million FCEVs leads to a 3% increase in electricity load for WECC. Our results show that an inflexible hydrogen-producing process leads to a 1.55% increase to the average cost of electricity while a flexible scenario leads to only a 0.9% increase. On the other hand oversized electrolyzers could take advantage of cheaper electricity generation opportunities thus lowering total system costs.

The shift to renewable energy sources requires systems that are not only environmentally sustainable but also cost-effective and reliable. Mitigating the inherent intermittency of renewable energy optimally managing the hybrid energy storage efficiently integrating the microgrid with the power grid and maximizing the lifespan of system components are the significant challenges that need to be addressed. With this aim the paper proposes an economic viability assessment framework with an optimized dynamic operation approach to determine the most stable cost-effective and environmentally sound system for a specific location and demand. The green integrated hybrid microgrid combines photovoltaic (PV) generation battery storage an electrolyzer a hydrogen tank and a fuel cell tailored for deployment in remote areas with limited access to conventional infrastructure. The study’s control strategy focuses on managing energy flows between the renewable energy resources battery and hydrogen storage systems to maximize autonomy considering real-time changes in weather conditions load variations and the state of charge of both the battery and hydrogen storage units. The core system’s components include the interlinking converter which transfers power between AC and DC grids and the decentralized droop control approach which adjusts the converter’s output to ensure balanced and efficient power sharing particularly during overload conditions. A cloud-based Internet of Things (IoT) platform has been employed allowing continuous monitoring and data analysis of the green integrated microgrid to provide insights into the system's health and performance during the dynamic operation. The results presented in this paper confirmed that the proposed framework enabled the strategic use of energy storage particularly hydrogen systems. The optimal operational control of green hydrogen-integrated microgrid can indeed mitigate voltage and frequency fluctuations caused by variable solar input ensuring stable power delivery without reliance on the main grid or fossil fuel backups.

Adverse climate change has forced a deeper reflection on the scale of pollution related to human activity including in the aviation industry. As a result fundamental questions have arisen about the characteristics of these pollutants the mechanisms of their formation and potential strategies for reducing them. This paper provides a comprehensive overview of key technical solutions to minimize the environmental impact of aircraft engines. The solutions presented range from fuel innovations to advanced design changes and drive concepts. Particular attention was paid to sustainable aviation fuels (SAFs) which are currently an important element of the environmental strategy regulated by the European Union. It also discusses the potential use of hydrogen as a potential alternative fuel to replace traditional aviation fuels in the long term. The analysis in the article made it possible to characterize in detail possible modifications in the functioning of aircraft engines based both on the current state of technical knowledge and on the anticipated directions of its development which has not been a frequent issue in comprehensive research so far. The analysis shows that the type of raw material used to create SAF has a strong impact on its physical and chemical parameters and the degree of greenhouse gas emissions. This necessitates a broader analysis of the legitimacy of using a given type of fuel from the SAF group in the direction of selected air operations and areas with a higher risk of severe atmospheric pollution. These results provide the basis for further research into sustainable solutions in the aviation sector that can contribute to significantly reducing its impact on climate change.

This paper presents a preliminary feasibility study for integrating hydro-pneumatic energy storage (HPES) with off-grid offshore wind turbines and green hydrogen production facilities—a concept termed HydroGenEration (HGE). This study compares the performance of this innovative concept system with an off-grid direct wind-to-hydrogen plant concept without energy storage both under central Mediterranean wind conditions. Numerical simulations were conducted at high temporal resolution capturing 10-min fluctuations of open field measured wind speeds at an equivalent offshore wind turbine (WT) hub height over a full 1-year seasonal cycle. Key findings demonstrate that the HPES system of choice namely the Floating Liquid Piston Accumulator with Sea Water under Compression (FLASC) system significantly reduces Proton Exchange Membrane (PEM) electrolyser (PEMEL) On/Off cycling (with a 66% reduction in On/Off events) while maintaining hydrogen production levels despite the integration of the energy storage system which has a projected round-trip efficiency of 75%. The FLASC-integrated HGE solution also marginally reduces renewable energy curtailment by approximately 0.3% during the 12-month timeframe. Economic analysis reveals that while the FLASC HPES system does introduce an additional capital cost into the energy chain it still yields substantial operational savings exceeding EUR 3 million annually through extended PEM electrolyser lifetime and improved operational efficiency. The Levelized Cost of Hydrogen (LCOH) for the FLASC-integrated HGE system which is estimated to be EUR 18.83/kg proves more economical than a direct wind-to-hydrogen approach with a levelized cost of EUR 21.09/kg of H2 produced. This result was achieved through more efficient utilisation of wind energy interfaced with energy storage as it mitigated the natural intermittency of the wind and increased the lifecycle of the equipment especially that of the PEM electrolysers. Three scenario models were created to project future costs. As electrolyser technologies advance cost reductions would be expected and this was one of the scenarios envisaged for the future. These scenarios reinforce the technical and economic viability of the HGE concept for offshore green hydrogen production particularly in the Mediterranean and in regions having similar moderate wind resources and deeper seas for offshore hybrid sustainable energy systems.

Urban Air Mobility (UAM) is gaining attention as a solution to urban population growth and air pollution. Hydrogen fuel cells are applied to overcome the limitations of battery-based UAM utilizing a PEMFC (Polymer Electrolyte Membrane Fuel Cell) with batteries in a hybrid system to enhance responsiveness. Power management improves efficiency through effective power distribution under varying loads while thermal management maintains optimal stack temperatures to prevent degradation. This study developed a hydrogen fuel cell–battery hybrid multicopter system using AMESim consisting of a 138 kW fuel cell stack 60 kW battery DC–DC converters and thrust motors. A rule-based power management system was implemented to define power distribution strategies based on SOC and load demand. The system’s operating range was designed to allocate power according to battery SOC and load variations. For an initial SOC of 45% the power management system distributed power for flight and the results showed that the state machine control system reduced hydrogen consumption by 5.85% and parasitic energy by 1.63% compared to the rule-based system.

The high volumetric capacity (53 g H2/L) and its low toxicity and flammability under ambient conditions make formic acid a promising hydrogen energy carrier. Particularly in the past decade significant advancements have been achieved in catalyst development for selective hydrogen generation from formic acid. This Perspective highlights the advantages of this approach with discussions focused on potential applications in the transportation sector together with analysis of technical requirements limitations and costs.

This study proposes the SMR Smart Net-Zero City (SSNC) framework—a scalable model for achieving carbon neutrality by integrating Small Modular Reactors (SMRs) renewable energy sources and sector coupling within a microgrid architecture. As deploying renewables alone would require economically and technically impractical energy storage systems SMRs provide a reliable and flexible baseload power source. Sector coupling systems—such as hydrogen production and heat generation—enhance grid stability by absorbing surplus energy and supporting the decarbonization of non-electric sectors. The core contribution of this study lies in its real-time data emulation framework which overcomes a critical limitation in the current energy landscape: the absence of operational data for future technologies such as SMRs and their coupled hydrogen production systems. As these technologies are still in the pre-commercial stage direct physical integration and validation are not yet feasible. To address this the researchers leveraged real-time data from an existing commercial microgrid specifically focusing on the import of grid electricity during energy shortfalls and export during solar surpluses. These patterns were repurposed to simulate the real-time operational behavior of future SMRs (ProxySMR) and sector coupling loads. This physically grounded simulation approach enables highfidelity approximation of unavailable technologies and introduces a novel methodology to characterize their dynamic response within operational contexts. A key element of the SSNC control logic is a day–night strategy: maximum SMR output and minimal hydrogen production at night and minimal SMR output with maximum hydrogen production during the day—balancing supply and demand while maintaining high SMR utilization for economic efficiency. The SSNC testbed was validated through a seven-day continuous operation in Busan demonstrating stable performance and approximately 75% SMR utilization thereby supporting the feasibility of this proxy-based method. Importantly to the best of our knowledge this study represents the first publicly reported attempt to emulate the real-time dynamics of a net-zero city concept based on not-yet-commercial SMRs and sector coupling systems using live operational data. This simulation-based framework offers a forward-looking data-driven pathway to inform the development and control of next-generation carbon-neutral energy systems.

This study explores the performance and emissions characteristics of a dual-fuel internal combustion engine operating on a blend of hydrogen and gasoline. This research began with a baseline simulation of a conventional gasoline engine which was subsequently validated through experimental testing on an AVL testbed. The simulation results closely matched the testbed data confirming the accuracy of the model with deviations within 5%. Building on this validated model a hydrogen–gasoline dual-fuel engine simulation was developed. The predictive simulation revealed an approximately 5% increase in overall engine efficiency at the optimal operating point primarily due to hydrogen’s combustion properties. Additionally the injected gasoline mass and CO2 emissions were reduced by around 30% across the RPM range. However the introduction of hydrogen also resulted in a slight reduction (~10%) in torque attributed to the lower volumetric efficiency caused by hydrogen displacing intake air. While CO emissions were significantly reduced NOx emissions nearly doubled due to the higher combustion temperatures associated with hydrogen. This research demonstrates the potential of hydrogen–gasoline dual-fuel systems in reducing carbon emissions while highlighting the need for further optimization to balance performance with environmental impact.

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.