Publications

The demand for green hydrogen (H2) and related technologies is expected to increase in the coming years driven by climate changes and energy security of supply issues amid the European and global energy crises. The European Green Deal and REpowerEU Plan have identified H2 as a key pillar for reaching climate neutrality by 2050 and for the intensification of hydrogen delivery targets bringing the large-scale adoption of hydrogen production and applications and stressing the need for a skilled workforce in emergent H2 markets. To that end the H2Excellence project will establish a Platform of Vocational Excellence in the field of fuel cells and green hydrogen technologies with an educational and training scheme to tackle identified skill gaps and to implement life-long learning opportunities. This project aims to become a European benchmark in training and knowledge transfer incorporating the entire hydrogen value chain. The work is supported by the Knowledge Triangle Model integrating education research and innovation efforts to build a dynamic ecosystem in the green hydrogen sector. In this work activities conducted so far by LNEG as a project partner and expected impacts are highlighted. Those activities are based on a stakeholder needs assessment conducted by project partners and on the knowledge and experience accumulated in research activities developed in the Materials for Energy research area.

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.

: In remote areas or islands like Cyprus the isolated energy system high energy consumption in the transport sector and projected excess electricity production from solar sources create favourable conditions for establishing a hydrogen valley. But even after addressing technological managerial economic and financial challenges the success of a hydrogen valley hinges on the acceptance and engagement of the local population. The role of citizens is under-researched by academia and overlooked by policymakers. Our paper’s contribution is unique data from a purposefully developed survey of Cypriot residents. The findings reveal robust support for the renewable energy transition in principle with 90% expressing supportive views of which 57% ‘strongly support’ the transition and notably middle-aged more educated and fully employed individuals showing the strongest support. At the same time our results show that 62% are unfamiliar with the concept of a hydrogen economy. The promising finding is that 80% of citizens are ‘very likely’ (25%) or ‘somewhat likely’ (55%) to engage in discussions or activities related to the creation of a hydrogen valley in Cyprus. Gender differences in the willingness to engage are however evident: 32% of males indicated they are ‘very likely’ to participate versus 23% of females. We conclude that the prevailing citizen behaviour in Cyprus is “Seeking Information” and we make policy suggestions outlining the top ten engagement tools to foster awareness among the general population and the top ten strategies targeting active supporters of hydrogen in Cyprus to elevate their involvement to ‘Action’ and ‘Advocacy’ levels of engagement.

Cryogenic vessels are widely used in many areas such as liquefied natural gas (LNG) aerospace and medical fields. A suitable filling method is one of the prerequisites for the effective use of cryogenic containers. In this study the filling process for the sloshing condition of a liquid hydrogen storage tank is numerically simulated and analyzed by coupling the sloshing model and the phase-change model. The effects of different sloshing conditions during the filling process are investigated by changing the amplitude and frequency of the sloshing. Within the scope of this study there is a critical value for the effect of sloshing conditions on the pressure curve during the filling process. The critical value corresponds to a frequency f equal to 3 Hz and an amplitude A equal to 0.03 m. According to the simulation results when the sloshing exceeds the critical value the internal pressure curve of the storage tank increases significantly. Under microgravity conditions within the scope of this study the pressure curve changes less than the normal gravity even if the amplitude and frequency increase. The sloshing makes it easier for the liquid to spread along the wall during the filling process. This also further weakens the temperature stratification in the storage tank.

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.

The escalating urgency to address climate change has sparked unprecedented interest in green hydrogen as a clean energy carrier. The intermittent nature of Renewable Energy Sources (RES) like wind and solar can introduce unpredictability into the energy supply potentially causing mismatches in the power grid. To this end green hydrogen production can provide a solution by enhancing system flexibility thereby accommodating the fluctuations and stochastic characteristics of RES. Furthermore green hydrogen could play a pivotal role in decarbonizing hard-to-abate sectors and promoting sector coupling. This research article endeavors to delve into this subject by developing a dynamic techno-economic analysis tool capable of flexibly assessing the optimal setup of Alkaline (AEL) electrolysis coupled with RES in a specific region or hub. The focus lies on achieving costeffectiveness efficiency and sustainable production of green hydrogen. The tool leverages a comprehensive dataset covering a full year of hourly data on both renewable electricity production from intermittent RES and wholesale electricity market prices alongside customizable inputs from users. It can be applied across various scenarios including direct coupling with dedicated RES plants and hybrid configurations utilizing the electricity grid as a backup source. The model optimizes RES electrolyser and hydrogen storage capacities to minimize the Levelized Cost of Hydrogen (LCOH) and/or the operational Carbon Intensity (CI) of hydrogen produced. The tool is applied within a real-world application study in the framework of the TRIERES Hydrogen Valley Project which is taking shape in Peloponnese Greece. For the various configurations analysed the LCOH ranges from 7.75 to 12.68 €/kgH2. The cost-optimal system configuration featuring a hybrid RES power supply of 12 MW solar and 19 MW wind energy alongside with 3.5 tonnes of hydrogen storage leads to a minimum LCOH of 7.75 €/kgH2. Subsidies on electrolyser stack and balance of plant CAPEX can reduce LCOH by up to 0.6 €/kgH2.

Ammonia is gaining attention as a non-carbon environmental-friendly fuel due to its superior storage capability compared to hydrogen. However its high minimum ignition energy and slow laminar flame speed make it unsuitable for application in combustion-based energy conversion devices. In particular when applied to internal combustion engines issues such as combustion instability and limitations in operational range exist. Therefore the intention is to address these issues by adding hydrogen which has a wider flammable range and a faster laminar flame speed to ammonia. In this study the extension of the operable range of ammonia-fueled spark ignition engine by hydrogen addition was mainly discussed. Ammonia was injected directly in the cylinder and hydrogen was supplied into the intake port. The result showed that operable range of ammonia fueled combustion with hydrogen addition could be extended from 0.2 to 1.4 MPa with relatively stable combustion i.e. CoV of gIMEP

The global resurgence of hydrogen as a clean energy source particularly green hydrogen derived from renewable energy is pivotal for achieving a carbon-neutral future. However scalability poses a significant challenge. This research proposes innovative business models leveraging the low-emission property of green hydrogen to reduce its financial costs thereby fostering its widespread adoption. Key components of the business workflow are elaborated mathematical formulations of market parameters are derived and case studies are presented to demonstrate the feasibility and efficiency of these models. Results demonstrate that the substantial costs associated with the current hydrogen industry can be effectively subsidized via the implementation of proposed business models. When the carbon emission price falls within the range of approximately 86–105 USD/ton free access to hydrogen becomes a viable option for end-users. This highlights the significance and promising potential of the proposed business models within the green hydrogen credit framework.

The subject of this study is the analysis of influence of capillary threshold pressure and injection well location on the dynamic CO2 and H2 storage capacity for the Lower Jurassic reservoir of the Sierpc structure from central Poland. The results of injection modeling allowed us to compare the amount of CO2 and H2 that the considered structure can store safely over a given time interval. The modeling was performed using a single well for 30 different locations considering that the minimum capillary pressure of the cap rock and the fracturing pressure should not be exceeded for each gas separately. Other values of capillary threshold pressure for CO2 and H2 significantly affect the amount of a given gas that can be injected into the reservoir. The structure under consideration can store approximately 1 Mt CO2 in 31 years while in the case of H2 it is slightly above 4000 tons. The determined CO2 storage capacity is limited; the structure seems to be more prospective for underground H2 storage. The CO2 and H2 dynamic storage capacity maps are an important element of the analysis of the use of gas storage structures. A much higher fingering effect was observed for H2 than for CO2 which may affect the withdrawal of hydrogen. It is recommended to determine the optimum storage depth particularly for hydrogen. The presented results important for the assessment of the capacity of geological structures also relate to the safety of use of CO2 and H2 underground storage space.

The utilization of hydrogen as an energy carrier and reduction agent in important industrial sectors is considered a key parameter on the way to a sustainable future. Steam reforming of methane is currently the most industrially used process to produce hydrogen. One major drawback of this method is the simultaneous generation of carbon dioxide. Methane pyrolysis represents a viable alternative as the basic reaction produces no CO2 but solid carbon besides hydrogen. The aim of this study is the investigation of different molten copper alloys regarding their efficiency as catalytic media for the pyrolysis of methane in an inductively heated bubble column reactor. The conducted experiments demonstrate a strong influence of the catalyst in use on the one hand on the conversion rate of methane and on the other hand on the properties of the produced carbon. Optimization of these parameters is of crucial importance to achieve the economic competitiveness of the process.