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This research investigates the optimization of a dry-type alkaline HHO kit for efficient oxyhydrogen (HHO) gas production, targeting applications in small (two-wheel vehicle) internal combustion engines (ICE). Key experimental parameters were evaluated to enhance gas production and system efficiency, including voltage, electrode configuration, electrolyte type, and concentration. Sodium hydroxide (NaOH) was identified as a more effective electrolyte than potassium hydroxide (KOH) due to its lower electronegativity, which contributes to accelerating HHO gas production. The highest overall efficiency, 24.6%, was achieved with a 0.1M NaOH solution using stainless steel (SS) as the anode and Titanium (Ti) as the cathode, and SS paired with graphite scored 23.1%. Voltage levels positively influenced gas production, although higher potentials resulted in electrode surface oxidation and decreased efficiency. The optimum voltage range of 4.5V to 5.2V for SS with graphite and 4.2V to 5.2V for SS with Ti configurations was provided. The study concludes that the SS-Ti and SS-Graphite configurations are optimal options for HHO gas production, minimizing heat generation and energy consumption while enhancing gas output. These findings suggest significant potential for improving fuel efficiency and reducing greenhouse gas emissions in two-wheel vehicle four-stroke gasoline engines (100cc to 150cc).

The intrinsic factor of variability of renewable energy sources often limits their broader use. The photovoltaic solar systems can be provided with a power back up based on a combination of an electrolyser and a fuel cell stack. The integration of solar hydrogen power systems with greenhouse heating equipment can provide a possible option for powering stand-alone greenhouses. The aim of the research under development at the experimental farm of Department of Agro-Environmental Sciences of the University of Bari Aldo Moro is to investigate on the suitable solutions of a power system based on photovoltaic energy and on the use of hydrogen as energy vector, integrated with a ground source heat pump for greenhouse heating in a self sustained way. The excess energy produced by a purpose-built array of solar photovoltaic modules supplies an alkaline electrolyser; the produced hydrogen gas is stored in pressured storage tank. When the solar radiation level is insufficient to meet the heat pump power demand, the fuel cell starts converting the chemical energy stored by the hydrogen fuel into electricity. This paper reports on the description of the realised system. Furthermore the efficiency and the operational mode of the electrolyser were evaluated during a trial period characterised by mutable solar radiant energy. Anyway the electrolyser worked continuously in a transient state producing fluctuations of the hydrogen production and without ever reaching the steady-state conditions. The Faradic efficiency, evaluated by means of an empirical mathematic model, highlights that the suitable working range of the electrolyser was 1.5÷2.5 kW and then for hydrogen production more than 0.21 Nm³h–¹.

The safety engineering design of hydrogen systems and infrastructure, worker education and training, regulatory compliance, and engagement with other stakeholders are significant to the viability and public acceptance of hydrogen farms. The only way to ensure these are accomplished is for the field of hydrogen safety engineering (HSE) to grow and mature. HSE is described as the application of engineering and scientific principles to protect the environment, property, and human life from the harmful effects of hydrogen-related mishaps and accidents. This paper describes a whole hydrogen farm that produces hydrogen from seawater by alkaline and proton exchange membrane electrolysers, then details how the hydrogen gas will be used: some will be stored for use in a combined-cycle gas turbine, some will be transferred to a liquefaction plant, and the rest will be exported. Moreover, this paper describes the design framework and overview for ensuring hydrogen safety through these processes (production, transport, storage, and utilisation), which include legal requirements for hydrogen safety, safety management systems, and equipment for hydrogen safety. Hydrogen farms are large-scale facilities used to create, store, and distribute hydrogen, which is usually produced by electrolysis using renewable energy sources like wind or solar power. Since hydrogen is a vital energy carrier for industries, transportation, and power generation, these farms are crucial in assisting the global shift to clean energy. A versatile fuel with zero emissions at the point of use, hydrogen is essential for reaching climate objectives and decarbonising industries that are difficult to electrify. Safety is essential in hydrogen farms because hydrogen is extremely flammable, odourless, invisible, and also has a small molecular size, meaning it is prone to leaks, which, if not handled appropriately, might cause fires or explosions. To ensure the safe and dependable functioning of hydrogen production and storage systems, stringent safety procedures are required to safeguard employees, infrastructure, and the surrounding environment from any mishaps.

NiFe electrodes are developed for the oxygen evolution reaction (OER) in an alkaline electrolyser based on an anion exchange membrane (AEM) separator and fed with diluted KOH solution as supporting electrolyte. This study reports on the electrochemical behaviour of two different NiFe-oxide compositions (i.e., Ni1Fe1-oxide and Ni1Fe2-oxide) prepared by the oxalate method. These catalysts are assessed for single-cell operation in an MEA including a Sustainion™ anion-exchange membrane. The electrochemical polarization shows a current density of 650 mA cm−2 at 2 V and 50 °C for the Ni1Fe1 anode composition. A durability test of 500 h is carried out using potential cycling as an accelerated stress-test. This shows a decrease in current density of 150 mA cm−2 mainly during the first 400 h. The performance achieved for the anion-exchange membrane electrolyser single-cell based on the NiFeOx catalyst appears promising. However, further improvements are required to enhance the stability under these operating conditions.

This paper proposes a Hybrid Microgrid (HμG) model including distributed generation (DG) and a hydrogen-based storage system, controlled through a tailored control strategy. The HμG is composed of three DG units, two of them supplied by solar and wind sources, and the latter one based on the exploitation of theProton Exchange Membrane (PEM) technology. Furthermore, the system includes an alkaline electrolyser, which is used as a responsive load to balance the excess of Variable Renewable Energy Sources (VRES) production, and to produce the hydrogen that will be stored into the hydrogen tank and that will be used to supply the fuel cell in case of lack of generation. The main objectives of this work are to present a validated dynamic model for every component of the HμG and to provide a strategy to reduce as much as possible the power absorption from the grid by exploiting the VRES production. The alkaline electrolyser and PEM fuel cell models are validated through real measurements. The State of Charge (SoC) of the hydrogen tank is adjusted through an adaptive scheme. Furthermore, the designed supervisor power control allows reducing the power exchange and improving the system stability. Finally, a case, considering a summer load profile measured in an electrical substation of Politecnico di Torino, is presented. The results demonstrates the advantages of a hydrogen-based micro-grid, where the hydrogen is used as medium to store the energy produced by photovoltaic and wind systems, with the aim to improve the self-sufficiency of the system.

This paper proposes a model of an electrolyser in the form of a subcircuit dedicated for SPICE. It takes into account both the electric static and dynamic properties of the considered device and is devoted to the optimisation of the parameters of the signal feeding this electrolyser, making it possible to obtain a high productivity and efficiency of the electrolysis process. Parameter values the describing current-voltage characteristics of the electrolyser take into account the influence of the concentration of the potassium hydroxide (KOH) solution. A detailed description of the structure and all the components of this model is included in the paper. The correctness of the elaborated model is verified experimentally in a wide range of changes in the value of the feeding current and concentration of the KOH solution. Some computations illustrating the influence of the amplitude, average value, duty factor, and frequency of feeding current on the productivity and efficiency of the electrolysis process are performed. On the basis of the obtained results of the investigations, some recommendations for the operating conditions of electrolysers are formulated.

In this work, the influence of the synthesis conditions on the structure, morphology, and electrocatalytic performance for the oxygen evolution reaction (OER) of Mn-Co-based films is studied. For this purpose, Mn-Co nanofilm is electrochemically synthesised in a one-step process on nickel foam in the presence of metal nitrates without any additives. The possible mechanism of the synthesis is proposed. The morphology and structure of the catalysts are studied by various techniques including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The analyses show that the as-deposited catalysts consist mainly of oxides/hydroxides and/or (oxy)hydroxides based on Mn2+, Co2+, and Co3+. The alkaline post-treatment of the film results in the formation of Mn-Co (oxy)hydroxides and crystalline Co(OH)2 with a β-phase hexagonal platelet-like shape structure, indicating a layered double hydroxide structure, desirable for the OER. Electrochemical studies show that the catalytic performance of Mn-Co was dependent on the concentration of Mn versus Co in the synthesis solution and on the deposition charge. The optimised Mn-Co/Ni foam is characterised by a specific surface area of 10.5 m2·g−1, a pore volume of 0.0042 cm3·g−1, and high electrochemical stability with an overpotential deviation around 330–340 mV at 10 mA·cm−2geo for 70 h.

An alkaline electrolyser was developed and characterized. Three different metals, working as the electrode, were analysed using electrochemical methods to determine the best electrochemical performance. The performance of the Stainless Steel (SS316) electrode and the nickel electrode is much better than that of the conventional iron electrode. Degradation analysis of the electrode materials highlighted the need for the material to be durable and resistant to corrosion from an alkaline environment. Through SEM and mass analysis, it is shown that Nickel exhibits the strongest long-term resistance to surface and electrochemical performance degradation, when compared with Mild Steel (Iron) and SS316.

Controlling the frequency of power systems with high wind power penetration is more difficult due to the high variability of the wind power. One possible mainstream energy carrier in the future, particularly for the transportation sector, is Hydrogen, and water electrolysis is one of the most attractive ways to produce it. In this study, a detailed model of a steam turbine generator has been produced in MATLAB Simulink and used to investigate a scenario in which there is a 25% penetration of wind power. To improve the frequency stability of the power system, large scale alkaline electrolysers used in future Hydrogen filling stations could adjust their load with respect to the frequency deviation from nominal and can significantly reduce fluctuations in system frequency. For the case examined, five times less spinning reserve is required in order to maintain the power system frequency within operational limits when electrolysers are utilised as a form of demand side management (DSM), compared to the base case where no electrolyser DSM plant is available. Actual operational data from a pressurised alkaline electrolyser is used to evidence the fast load changing capability of such electrolysers.

In recent years, the utilization of aluminium (Al), Al alloys, and their composite powder and anode encourages the generation of green hydrogen through hydrolysis and water splitting electrolysis with zero emissions. As such, in this study, the development and characterization of Al, Al alloys, and Al-based composite powder and compacted Al composites for clean hydrogen production using hydrolysis and water splitting processes were reviewed. Herein, based on the available literature, it is worth mentioning that the incorporation of active additives, such as h-BN, Bi@C, g-C 3 N 4 , MoS 2 , Ni, In, Fe, and BiOCl@CNTs in the Al-based composites using ball milling, melting, smelting, casting, and spark plasma sintering technique remarkably improved the rate of hydrogen evolution and hydrogen gas conversion yield, particularly during hydrolysis of Al-water reaction. Again, Al-based electrodes with improved electrical conductivity notably results in better water splitting electrolysis, as well as fast chemical reaction in achieving hydrogen gas production at low energy consumption with efficiency. Though, notwithstanding the significance of Al, Al alloy, and Al-based composite hydrogen generation performances, there are still some challenges associated with the Al-based materials for hydrogen production via hydrolysis and water electrolysis. For example, the low current density and poor electrochemical properties of Al, which on the other hand results in long induction time, high overpotential and cost remains a gap to bridge. Hence, the authors concluded the review study with recommendations for future improvement of Al-based composite electrodes on hydrogen production and sustainability via hydrolysis and water electrolysis. Thus, the study will pave the way for further research on clean hydrogen energy generation.