Publications

This work describes a thermodynamic comparison of the thermal efficiency of gas turbine engines featuring a conventional combustion chamber and a detonation combustion chamber using methane ethanol and mixtures of both ethanol and hydrogen and methane and hydrogen as fuels. The composition of gases was determined by the minimization of the Gibbs free energy whereas temperature pressure and velocity of detonation waves were determined by the Chapman-Jouguet theory. The results obtained here show that the DCC gas turbine cycle has a higher net work output and thermal efficiency than the CCC gas turbine cycle for all fuels studied in this work. The maximum thermal efficiency obtained with the DCC gas turbine cycle is indeed 57.22% which represents a 53.75% improvement over the maximum thermal efficiency obtained with the CCC gas turbine cycle (which has a peak thermal efficiency of 37.22%) under the same pressure ratio and turbine inlet temperature.

This study explored the optimization of green hydrogen production via seawater electrolysis powered by a hybrid photovoltaic (PV)-wind system in KwaZulu-Natal South Africa. A Box–Behnken Design (BBD) adapted from Response Surface Methodology (RSM) was utilized to address the synergistic effect of key operational factors on the integration of renewable energy for green hydrogen production and its economic viability. Addressing critical gaps in renewable energy integration the research evaluated the feasibility of direct seawater electrolysis and hybrid renewable systems alongside their techno-economic viability to support South Africa’s transition from a coal-dependent energy system. Key variables including electrolyzer efficiency wind and PV capacity and financial parameters were analyzed to optimize performance metrics such as the Levelized Cost of Hydrogen (LCOH) Net Present Cost (NPC) and annual hydrogen production. At 95% confidence level with regression coefficient (R2 > 0.99) and statistical significance (p < 0.05) optimal conditions of electricity efficiency of 95% a wind-turbine capacity of 4960 kW a capital investment of $40001 operational costs of $40000 per year a project lifetime of 29 years a nominal discount rate of 8.9% and a generic PV capacity of 29 kW resulted in a predictive LCOH of 0.124$/kg H2 with a yearly production of 355071 kg. Within the scope of this study with the goal of minimizing the cost of production the lowest LCOH observed can be attributed to the architecture of the power ratios (Wind/PV cells) at high energy efficiency (95%) without the cost of desalination of the seawater energy storage and transportation. Electrolyzer efficiency emerged as the most influential factor while financial parameters significantly affected the cost-related responses. The findings underscore the technical and economic viability of hybrid renewable-powered seawater electrolysis as a sustainable pathway for South Africa’s transition away from coal-based energy systems.

As the world shifts towards renewable energy sources the need for reliable large-scale energy storage solutions becomes increasingly critical. Underground Hydrogen Storage (UHS) emerges as a promising option to bridge this gap. However the success of UHS heavily depends on the durability of infrastructure materials particularly cement in wellbores and in unlined rock caverns (URCs) where it serves a dual role in grouting and sealing. This study explores the chemical interactions between hydrogen and cement in these environments exploring how hydrogen might compromise cement integrity over time. We employed advanced thermodynamic analyses kinetic batch tests and 1D reactive transport models to simulate the behaviour of cement when exposed to hydrogen under conditions found in two potential UHS sites: the Haje URC in the Czech Republic and a depleted gas field in the Perth Basin Western Australia. Our results reveal that while certain cement phases are vulnerable to dissolution the overall increase in porosity is minimal suggesting a lower risk of significant degradation. Notably hydrogen was found to penetrate 5 cm of cement within just 4–5 days at both sites. These insights are crucial for enhancing the design and maintenance strategies of UHS facilities. Moreover this study not only advances our understanding of material sciences in the context of hydrogen energy storage but also underscores the importance of sustainable infrastructure in the transition away from fossil fuels.

Hydrogen is increasingly recognized as a clean energy vector and storage medium yet its viability and strategic role in the Western Balkans remain underexplored. This study provides the first comprehensive techno-economic environmental and strategic evaluation of hydrogen production pathways in Albania. Results show clear trade-offs across options. The levelized cost of hydrogen (LCOH) is estimated at 8.76 €/kg H2 for grid-connected 7.75 €/kg H2 for solar and 7.66 €/kg H2 for wind electrolysis—values above EU averages and reliant on lower electricity costs and efficiency gains. In contrast fossil-based hydrogen via steam methane reforming (SMR) is cheaper at 3.45 €/kg H2 rising to 4.74 €/kg H2 with carbon capture and storage (CCS). Environmentally Life Cycle Assessment (LCA) results show much lower Global Warming Potential.

Offshore energy system integration is particularly important for realising a rapid and cost-effective low-carbon energy transition in the North Sea region. Effective implementation of strategies that require collaboration be tween countries developers and operators must be underpinned by robust and comprehensive modelling results. Intra-system interactions and diversity of sectors needed to facilitate the energy transition must be adequately captured within whole-system models. Historically consideration of the offshore energy environment within macro-scale models has been supplementary to the onshore system. However increased deployment of offshore wind focus on geological storage for energy security and technological development and investment in hydrogen and carbon storage projects highlights the importance of expanding the role of the offshore system within modelling. This study presents a comprehensive investigation of energy system integration challenges within offshore system modelling and how these define the requirements of the employed methodology. The findings suggest large-scale offshore system modelling studies typically include few energy vectors limited spatial resolution and simplified network flow characteristics. Despite the North Sea focus these challenges reflect fundamental barriers within large-scale offshore energy system modelling and thus extend to similar offshore contexts globally. Key approaches are identified to maximise sectoral and technological diversity while maintaining sufficient temporal and spatial resolution to suitably represent the evolving offshore system are identified. We make concrete suggestions for future work in this field based on identified best practice among the reviewed literature.

Hydrogen is an attractive energy carrier which could play a role in decarbonizing process heat power or transport applications. Though the U.S. already produces about 10 million metric tons of H2 (over 1 quadrillion BTUs or 1% of the U.S. primary energy consumption) production technologies primarily use fossil fuels that release CO2 and the deployment of other cleaner H2 production technologies is still in the very early stages in the U.S. This study explores (1) the level of current U.S. hydrogen production and demand (2) the importance of hydrogen to accelerate a net-zero CO2 future and (3) the challenges that must be overcome to make hydrogen an important part of the U.S. energy system. The study discusses four scenarios and hydrogen production has been shown to increase in the future but this growth is not enough to establish a hydrogen economy. In this study the characteristics of hydrogen technologies and their deployments in the long-term future are investigated using energy system model MARKAL. The effects of strong carbon constraints do not cause higher hydrogen demand but show a decrease in comparison to the business-as-usual scenario. Further according to our modeling results hydrogen grows only as a fuel for hard-to-decarbonize heavy-duty vehicles and is less competitive than other decarbonization solutions in the U.S. Without improvements in reducing the cost of electrolysis and increasing the performance of near-zero carbon technologies for hydrogen production hydrogen will remain a niche player in the U.S. energy system in the long-term future. This article provides the reader with a comprehensive understanding of the role of hydrogen in the U.S. energy system thereby explaining the long-term future projections.

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.

The energy hub (EH) concept is an efficient way to integrate various energy carriers. Inaddition demand response programmes (DRPs) are complementary to improving anEH's efficiency and increase energy system flexibility. The hydrogen storage system as agreen energy carrier has an essential role in balancing supply and demand preciselysimilar to other storage systems. A hybrid robust‐stochastic approach is applied herein toaddress fluctuations in wind power generation multiple demands and electricity marketprice in a hydrogen‐based smart micro‐energy hub (SMEH) with multi‐energy storagesystems. The proposed hybrid approach enables the operator to manage the existinguncertainties with more flexibility. Also flexible electrical and thermal demands under anintegrated demand response programme (IDRP) are implemented in the proposedSMEH. The optimal scheduling of the hydrogen‐based SMEH problem considering windpower generation and electricity market price fluctuations as well as IDRP is modelledvia a mixed‐integer linear programming problem. Finally the validity and applicability ofthe proposed model are verified through simulation and numerical results.

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.

The MultHyFuel project aims to develop evidence-based guidelines for the safe implementation of Hydrogen Refueling Stations (HRS) in a multi-fuel context. As a part of the generation of good practice guidelines for HRS Hazardous Area Classification (HAC) methodologies were analyzed and applied to case studies representing example configurations of HRS. It has been anticipated that Negligible Extent (NE) classifications might be applicable for sections of the HRS for instance a hydrogen generator. A NE zone requires that an ignition of a flammable cloud would result in negligible consequences. In addition depending on the pressure of the system IEC 60079-10-1:2020 establishes specific requirements in order to classify the hazardous area as being of NE. One such requirement is that a zone of NE shall not be applied for releases from flammable gas systems at pressures above 2000 kPag (20 barg) unless a specific detailed risk assessment is documented. However there is no definition within the standard as to the requirements of the specific detailed risk assessment. In this work an example for a specific detailed risk assessment for the NE classification is presented:<br/>• Firstly the requirements of cloud volume dilution and background concentration for a zone of NE classification from IEC 60079-10-1:2020 are analyzed for hydrogen releases from equipment placed in a mechanically ventilated enclosure.<br/>• Secondly the consequences arising from the ignition of the localized cloud are estimated and compared to acceptable harm criteria in order to assess if negligible consequences are obtained from the scenario.<br/>• In addition a specific qualitative risk assessment for the ignition of the cloud in the enclosure was considered incorporating the estimated consequences and analyzing the available safeguards in the example system.<br/>Recommendations for the specific detailed risk assessment are proposed for this scenario with the intention to support improved definition of the requirement in future revisions of IEC 60079-10-1.