Publications

Due to the privileged location of Ecuador in terms of solar radiation the analysis and use of renewable energy system (RES) using solar energy has been of great interest during the last years. At the same time the supply support of RES in terms of direct current (DC) can be faced by using fuel cell (FC) systems which can give to the systems fully autonomy from fossil fuels. The aim of this paper is to propose the design of a hybrid photovoltaic-fuel cell-battery (PV-FC-B) system to supply the required electrical energy for residential use in the city of Guayaquil. The feasibility analysis constitutive elements of the system and adjusted variables are computed and presented using a computational tool. The results evidence that this system is not economically viable since the cost of energy (COE) in Ecuador is low compared to the COE of the proposed system. However a more detailed analysis considering the inherent benefits of no emission of pollutant gases is required to have a complete outlook.

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.

Geological structures in deep aquifers and salt caverns can play an important role in large-scale hydrogen storage. However more work needs to be done to address the hydrogen storage demand for zero-emission energy systems. Thus the aim of the article is to present the demand for hydrogen storage expressed in the number of salt caverns in bedded rock salt deposits and salt domes or the number of structures in deep aquifers. The analysis considers minimum and maximum hydrogen demand cases depending on future energy system configurations in 2050. The method used included the estimation of the storage capacity of salt caverns in bedded rock salt deposits and salt domes and selected structures in deep aquifers. An estimation showed a large hydrogen storage potential of geological structures. In the case of analyzed bedded rock salt deposits and salt domes the average storage capacity per cavern is 0.05–0.09 TWhH2 and 0.06–0.20 TWhH2 respectively. Hydrogen storage capacity in analyzed deep aquifers ranges from 0.016 to 4.46 TWhH2. These values indicate that in the case of the upper bound for storage demand there is a need for the 62 to 514 caverns depending on considered bedded rock salt deposits and salt domes or the 9 largest analyzed structures in deep aquifers. The results obtained are relevant to the discussion on the global hydrogen economy and the methodology can be used for similar considerations in other countries.

The desire to maintain CO2 concentrations in the global atmosphere implies the need to introduce ’new’ energy carriers for transport applications. Therefore the operational consumption of each such potential medium in the ’natural’ exploitation of vehicles must be assessed. A useful assessment method may be the vehicle’s energy footprint resulting from the theory of cumulative fuel consumption presented in the article. Using a (very modest) database of long-term use of hydrogen-powered cars the usefulness of this method was demonstrated. Knowing the energy footprint of vehicles of a given brand and type and the statistical characteristics of the footprint elements it is also possible to assess vehicle fleets in terms of energy demand. The database on the use of energy carriers such as hydrogen in the long-term operation of passenger vehicles is still relatively modest; however as it has been shown valuable data can be obtained to assess the energy demand of vehicles of a given brand and type. Access to a larger operational database will allow for wider use of the presented method.

This project an essential part of the National Gas HyNTS programme endeavours to align the NTS with GB’s net zero ambitions by demonstrating the operational viability of the system with varying hydrogen blends using decommissioned assets typical of the natural gas network today ultimately aiming for 100% hydrogen conveyance. Several desktop studies were undertaken within the HyNTS programme to confirm the theoretical potential of the NTS to transport hydrogen safely and reliably. Further to these studies practical demonstration was deemed necessary to bridge the knowledge gaps and ensure the system’s transition maintains the utmost safety and reliability standards. A range of tests on decommissioned assets were conducted offline in a controlled environment to ensure robust outcomes that will ultimately start to build the safety case for a hydrogen network. The key deliverables and testing achievements of FutureGrid included: • Operational testing with natural gas and 2% 5% 20% and 100% hydrogen to verify the network’s ability to transport hydrogen and varying blends. • Standalone offline testing modules complementing evidence gathered on the main test facility. These address specific areas of concern including material permeation flange integrity asset leakage and rupture consequence which are essential for risk mitigation and safety assurance. FutureGrid is a global first facility and a critical part of National Gas’ hydrogen programme providing physical evidence of the capability of our network to transport hydrogen. It provides key evidence for hydrogen blending alongside 100% hydrogen pipelines which are planned under Project Union our Hydrogen Backbone across GB. FutureGrid is pivotal in the journey to reaching Net Zero by 2050 and is a fully operational proven technical demonstrator. FutureGrid’s repurposed assets are representative of today’s live high pressure gas network and have been subjected to testing at different blends of natural gas with hydrogen and 100% hydrogen; this was achieved with no major findings in differences in terms of how the assets interact with hydrogen. The overall project completion date was delayed from November 2023 to February 2024 due to technical issues with the newly built hydrogen re‑compressor. There were no changes made to the project costs.

This article analyzes and compares three methodologies for identifying suitable regions for solar hydrogen production using photovoltaic panels: AHP (Analytic Hierarchy Process) FAHP (Fuzzy Analytic Hierarchy Process) and MC-FAHP (Monte Carlo FAHP) integrated with GIS (Geographic Information Systems). The study employs ten criteria across technical (Global Horizontal Irra diance temperature slope elevation orientation) economic (distance from transportation and electrical networks) and social (population density proximity to residential areas) factors. Environmental and exclusion criteria define restrictive zones. The analysis reveals that while all three methods agree on areas of low suitability they diverge in their classification of "Suitable" "Highly Suitable" and "Most Suitable" regions. FAHP identifies 229.573 km2 as "Highly Suitable" compared to AHP’s 222.048 km2 and MC-FAHP’s 230.299 km2 for "Suitable" areas. Despite these differences the energy potential is consistent across methods totaling around 79000 TWh/year with MC-FAHP estimating the highest hydrogen production potential at 1.51 billion tons/year. The study concludes that fuzzy-based methods (FAHP and MC-FAHP) better handle uncertainties than traditional AHP. The MC-FAHP method in particular performs well in managing stochastic variability and yielding more reliable results. The findings are validated through a case study in Guider and Maroua highlighting the importance of socio-economic and environmental criteria in decision-making. A sensitivity analysis reveals that economic and social criteria significantly influence land suitability underscoring the importance of criteria selection in decision-making.

The significant growth of both the global population and economy in recent years has led to a rise in global energy demand. Fossil fuels have a significant contribution to generating energy which has raised concerns about sustainability and environmental impact. There are widespread efforts to find alternative sources in order to reduce dependence on fossil fuels and mitigate their environmental consequences. Among the alternative sources hydrogen has emerged as a promising option due to its potential to be a clean and sustainable energy source. Hydrogen possesses several advantages such as a high calorific value a high reaction rate various sources and the ability to integrate with other renewable energy sources and existing systems. These attributes render hydrogen a stable and reliable energy resource which can help reduce greenhouse gas emissions (GHG) and transition towards a sustainable future. In this review paper distinct hydrogen production technologies such as conventional renewable and nuclear energy are investigated and compared. In addition the challenges and limitations of the application of hydrogen fuel cells on vehicles and hydrogen circulation components are explored. Finally the environmental impact of hydrogen vehicles specifically their role in promoting sustainable development is investigated.

This week’s episode is a discussion between EAH hosts Patrick Molloy Alicia Eastman and Chris Jackson. The team cover the current status of hydrogen regulation innovation financing markets and consolidation. Hanging over most conversations in the decarbonization or future fuels space is the perpetual question: When will investors actually step up with significant capital to help companies make it through the development desert instead of letting promising companies languish in the double dunes of despair? There has been a lot of talk but not a lot of action. Listen to the team unpack recent developments and hopes for the future.

The podcast can be found on their website.

This paper investigates innovative solutions to enhance the performance and lifespan of standalone photovoltaic (PV)-based microgrids with a particular emphasis on off-grid communities. A major challenge in these systems is the limited lifespan of batteries. To overcome this issue researchers have created hybrid energy storage systems (HESS) along with advanced power management strategies. This study introduces innovative multi-level HESS approaches and a related energy management strategy designed to alleviate the charge/discharge stress on batteries. Comprehensive Matlab Simulink models of various HESS topologies within standalone PV microgrids are utilized to evaluate system performance under diverse weather conditions and load profiles for rural site. The findings reveal that the proposed HESS significantly extends battery life expectancy compared to existing solutions. Furthermore the paper presents a novel energy management strategy based on the Reduced Fractional Gradient Descent (RFGD) algorithm optimization tailored for hybrid systems that include photovoltaic fuel cell battery and supercapacitor components. This strategy aims to minimize hydrogen consumption of Fuel Cells (FCs) thereby supporting the production of green ammonia for local industrial use. The RFGD algorithm is selected for its minimal user-defined parameters and high convergence efficiency. The proposed method is compared with other algorithms such as the Lyrebird Optimization Algorithm (LOA) and Osprey Optimization Algorithm (OOA). The RFGD algorithm exhibits superior accuracy in optimizing energy management achieving a 15% reduction in hydrogen consumption. Its efficiency is evident from the reduced computational time compared to conventional algorithms. Although minor losses in computational resources were observed they were substantially lower than those associated with traditional optimization techniques. Overall the RFGD algorithm offers a robust and efficient solution for enhancing the performance of hybrid energy systems.

Tunisia's rapid industrial expansion and population growth have created a pressing energy deficit despite the country's significant yet largely untapped renewable energy potential. This study addressed this challenge by developing a comprehensive framework to identify and evaluate strategies for promoting green hydrogen production from renewable energy sources in Tunisia. A Strength Weakness Opportunity and Threat (SWOT) analysis incorporating social economic and environmental dimensions was conducted to formulate potential solutions. The Step-wise Weight Assessment Ratio Analysis (SWARA) method facilitated the weighting of SWOT factors and subfactors. Subsequently a multi-criteria decision-making approach employing the gray technique for order preference by similarity to ideal solution (TOPSIS-G) method (validated by gray additive ratio assessment (ARAS-G) gray complex proportional assessment (COPRAS-G) and gray multi-objective optimization by ratio analysis (MOORA-G) was used to rank the identified strategies. The SWOT analysis revealed "Strengths" as the most influential factor with a relative weight of 47.3% followed by "Weaknesses" (26.5%) "Threats" (15.6%) and "Opportunities" (10.6%). Specifically experts emphasized Tunisia's renewable energy potential (21.89%) and robust power system (12.11%) as primary strengths. Conversely high investment costs (11.2%) and political instability (7.77%) posed substantial threat. Positive socio-economic impacts represented a key opportunity with a score of 5.2%. As for the strategies prioritizing criteria production cost ranked first with a score of 13.5% followed by environmental impact (12.8%) renewable energy potential (12.0%) and mitigation costs (11.3%). The gray TOPSIS analysis identified two key strategies: leveraging Tunisia's wind and solar resources and fostering regional cooperation for project implementation. The robustness of these strategies is confirmed by the strong correlation between TOPSIS-G ARAS-G COPRAS-G and MOORA-G results. Overall the study provides a comprehensive roadmap and expert-informed decision-support tools offering valuable insights for policymakers investors and stakeholders in Tunisia and other emerging economies facing similar energy challenges.