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The rapid depletion of conventional fuel resources and rising energy demand has accelerated the search for alternative energy sources. Further, the expanding need to use bioenergy crops for sustainable fuel production has enhanced the competition for agricultural land, raising the "food vs. fuel" competition. Considering this, producing bioenergy crops on marginal land has a great perspective for achieving sustainable bioenergy production and mitigating the negative impacts of climate change. C4 crops are dual-purpose crops with better efficiency to fix atmospheric CO 2 and convert solar energy into lignocellulosic biomass. Of these, millets have gained worldwide attention due to their climate resilience and nutraceutical properties. Due to close synteny with contemporary C4 bioenergy crops, millets are being considered a model crop for studying diverse agronomically important traits associated with biomass production. Millets can be cultivated on marginal land with minimum fertilizer inputs and maximum biomass production. In this regard, advanced molecular approaches, including marker-assisted breeding, multi-omics approaches, and gene-editing technologies, can be employed to genetically engineer these crops for enhanced biofuel production efficiency. The current study aims to provide an overview of millets as a sustainable bioenergy source and underlines the significance of millets as a C4 model to elucidate the genes and pathways involved in lignocellulosic biomass production using advanced molecular biology approaches. • Millets, being C4 crops, are considered a model for studying agronomically and economically important traits. • Millets hold great potential as future bioenergy crops due to their climate resilience trait and high water use efficiency. • Millets can be cultivated on marginal land with minimum fertilizer inputs which is essential for resource optimization. • Advanced molecular approaches can help to genetically engineer these crops for optimized biofuel production efficiency. [ABSTRACT FROM AUTHOR]

Photocatalytic conversion of CO 2 into valuable fuels is considered a promising approach for the development of sustainable and renewable energy sources. In this study, we utilized Mo-MOF as a precursor to obtain MoO 3 by pyrolytic derivatization and treated it to obtain MOF-MoO 3-x containing oxygen vacancies as a catalyst for the photocatalytic reduction of CO 2 to CO. MOF derivatization altered the morphology of the MoO 3 , which made the formation of oxygen vacancies easier and facilitated the separation of electron-hole pairs. Meanwhile, the increased specific surface area and the appearance of surface oxygen vacancies enhanced the CO 2 adsorption and activation capabilities of MOF-MoO 3-x. As a result, MOF-MoO 3-x demonstrated a significant enhances in the photoreduction activity of CO 2. Its CO yield was 29.1 μmolg−1h−1, which was 3.7 times higher than that of MOF-MoO 3 and 2.4 times higher than that of H-MoO 3-x. This innovative strategy may provide a new avenue for improving the comprehensive performance of photocatalysts and developing renewable energy sources. MOF-MoO 3-x photocatalytic material derived from Mo-MOF precursor and prepared by ascorbic acid reduction. Compared to the H-MoO 3-x obtained by hydrothermal method, the MOF structure promoted the formation of oxygen defects, the yield of CO reduction by MOF-MoO 3-x had been significantly improved. [Display omitted] [ABSTRACT FROM AUTHOR]

Heat is produced by all machinery, including microprocessors and jet engines, as well as by industrial processes that produce goods from steel to food. There is still a strong desire for alternative energy sources in this day of ecologically conscious and sustainable energy needs. The recovery of heat from waste heat into beneficial electrical energy provides a simple energy source with enormous potential. Thermoelectrics is one of the popular technologies, which can convert heat into electricity, making them useful for power generation. Tin telluride (SnTe), a significant type of newly developed thermoelectric material, has drawn a lot of attention due to its low toxicity and environmentally friendly characteristics. Here, we synthesize Bi/Se co-doped SnTe (Sn 1-x Bi x Te 0.97 Se 0.03 (x = 0, 0.02, 0.04, 0.06)) samples by employing the solid-state metathesis route. The results of this work suggest that the combined action of cationic and anionic substitution of Bi and Se to SnTe matrix could potentially modify the microstructure and band structure of SnTe, thereby effectively improving its electronic, mechanical, and thermal transport properties. In line with the experimental findings, the samples show degenerate semiconducting electronic transport behaviour throughout the temperature range. The maximum Seebeck coefficient is found to be ∼84 μV/K and the total thermal conductivity is reduced to 1.6 W/mK at 573 K in a 6 % Bi-doped sample, which is 2.2 times less than the pristine sample. The Sn 0.94 Bi 0.06 Te 0.97 Se 0.03 sample has a maximum ZT of approximately 0.23 at 573 K, which is three times higher than the pristine sample because of the combined regulation of cation-anion co-doping and an elevated power factor of 936 μW/K2m in Sn 0.96 Bi 0.04 Te 0.97 Se 0.03 sample at 573 K, which is 1.82 times higher than that of pristine SnTe. Considering these findings, it appears that Bi-Se co-doped SnTe is a promising material for thermoelectric applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Developing highly efficient catalysts for the hydrogen evolution reaction (HER) is crucial for advancing renewable hydrogen energy technologies. Heterophase nanomaterials have shown great promise in catalysis, owing to the synergistic effect among various phases and the abundance of active sites located at the phase boundaries or interfaces. However, achieving precise control over these phase structures during synthesis remains a significant challenge. In this work, we explored a one-pot synthesis method for amorphous/crystalline heterophase Rh nanoparticles, with crystallinity tunable by adjusting the quantity of urea and reaction duration. Due to the increased electrochemical active sites, enhanced electron transport, the resulting amorphous/crystalline heterophase Rh exhibits superior HER activities in both acidic (with an overpotential of 27 mV) and alkaline media (with an overpotential of 21 mV), surpassing that of commercial Pt/C and crystalline Rh. Theoretical calculations indicate that the amorphous/crystalline structure reduces the kinetic barrier for water splitting and optimizes adsorption free energy of hydrogen (ΔG H∗), thereby enabling the catalyst to exhibit significantly enhanced HER performance. This exploration offers a valuable reference for designing amorphous/crystalline heterophase structures and demonstrates the great potential of phase engineering strategy in the development of electrocatalysts. [Display omitted] • Amorphous/crystalline heterophase Rh can be prepared with urea in a simple method. • The crystallinity can be tuned by modifying the amount of urea and reaction time. • Amorphous/crystalline Rh exhibited a higher HER performance than crystalline Rh. • Amorphous/crystalline structure optimizes adsorption energy of reactant. [ABSTRACT FROM AUTHOR]

The usage of non-renewable carbon-base fuel energy have created multiple issues such as global warming, environmental degradations etc. Replacing these non-renewable sources of energy with renewable energy (photocatalytic H 2 production) is a hot topic for researchers due to its sustainability and eco-friendliness. In this work MnO 2 , SnO 2 and their nanocomposites have been synthesized through simple hydrothermal and co-precipitation methods. The purpose of such nanocomposite fabrication is to synthesize a suitable heterostructure for maximum solar energy harvesting in water splitting. All the prepared samples of pure MnO 2 , SnO 2, and nanocomposites have been characterized through various techniques, which confirm the structure, functional groups, absorbance, morphology, elemental compositions, chemical compositions, and increase in photo-induced current as well as the photostability of such nanocomposites. The highest apparent quantum yield of the optimized MnO 2 @SnO 2 (first time reported as photocatalyst for H 2 production) were 21.7% at wavelength 420 nm, which is the highest ever reported for such (MnO 2 @SnO 2) nanocomposite. The enhanced photocatalytic behavior for H 2 production has been observed which is 3.67 times greater than pristine MnO 2. Such an enhancement is due to the synergistic effect of SnO 2 NPs decorated on the NTs of MnO 2. The present work provides a novel approach to produce hydrogen with high performance as efficient solar harvesting. • High-quality crystalline nanocomposites of MnO 2 @SnO 2 have been synthesized. • Various characterizations have been performed like XRD, FTIR, EDX, SEM, XPS, TEM, HR-TEM, EIS and GCG spectroscopies. • The suitable bandgap (MS-30) sample shows visible light absorption. • MS-30 nanocomposite shows an enhanced photocatalytic H 2 production performance. [ABSTRACT FROM AUTHOR]

The continuous growth in global energy demand has led to extensive burning and overconsumption of fossil fuels, resulting in a rapid increase in greenhouse gas emissions, primarily carbon dioxide. On one hand, the frequency and intensity of extreme weather events have increased dramatically due to global climate change. On the other hand, renewable energy sources are rapidly developing. Therefore, CO 2 electrochemical reduction technology has attracted considerable attention as a sustainable solution for converting CO 2 into valuable chemicals. Copper-based catalysts can efficiently reduce CO 2 directly to high-value chemicals, making them one of the focal points in CO 2 electrochemical reduction (eCO 2 RR) research. Many factors influence the activity and selectivity of eCO 2 RR, and this paper systematically reviews the recent advances in CO 2 electrochemical reduction using Cu-based catalysts. Firstly, the fundamental principles and reaction mechanisms of CO 2 electrochemical reduction are outlined. Subsequently, the discussion delves into Cu catalyst structures and composition synergistic control strategies, covering monometallic copper catalysts, multimetallic copper-based catalysts, copper oxides and their derived catalysts, and copper-organic composite catalysts. Finally, we also analyzed the challenges faced by Cu-based catalyst research and provided an outlook on the prospects of CO 2 electroreduction technology in conjunction with emerging AI technology. • Summarized the mechanisms of C 1 and C 2+ products in eCO 2 RR. • Summarized the application of five types of copper-based catalysts in eCO 2 RR. • Discussed the development prospects and strategies of eCO 2 RR in combination with AI. [ABSTRACT FROM AUTHOR]

This research investigates a sustainable and renewable mobile energy system designed for electricity production, hydrogen generation, and seawater desalination. It targets critical energy and freshwater needs during disaster scenarios, particularly in island nations and coastal cities where infrastructure may be compromised. The system integrates advanced technologies, including wind turbines, photovoltaic panels, solar collectors, and reverse osmosis units, all mounted on a green ship. Simulations using Engineering Equation Solver software indicate that in July, the system can produce 2,201,865 MJ of electricity, 7252 kg of hydrogen, and 3456 tons of fresh and hot water. This output can power 1072 electric vehicles and 1284 hydrogen-powered vehicles while supplying cold water to 57,600 people and hot water to 5760 people. By relying on renewable energy, the system prevents approximately 43,543 kg of carbon emissions in July. The total monthly economic value is estimated at $47,241.36, demonstrating its potential as a sustainable solution for disaster response and coastal communities. [Display omitted] • Hydrogen generation of the combined hybrid renewable system. • Thermodynamic efficiencies of components and overall the system for a green ship. • The comparison of the power generation of the wind turbine, Organic Rankine Cycle, and solar cell. • The monthly carbon saving quantity of the renewable hybrid system. [ABSTRACT FROM AUTHOR]

Wastewater treatment plants can provide a sustainable solution for hydrogen production by harnessing renewable energy and using treated water as feedstock as hydrogen demands in the future are expected to increase significantly. This study provides a decision-making model that enables the determination of optimal capacities of solar power, wind power, reverse osmosis, electrolyser, storage tank, and optimal hourly grid import. Such a project simultaneously provides electricity for hydrogen production and wastewater treatment, and sells hydrogen and renewable energy certificates. The planning aims to maximise the annual profits and renewable energy ratio. The case study shows that coupling a 120,000 m 3 /day plant scale with a 5 ton/day hydrogen facility shows a gross profit margin of 35.2%, a payback period of 7.2 years. This outperforms scenarios that exclude land and energy constraints in wastewater treatment plants. The influence of renewable energy ratios, hydrogen demand, and the prospective water usage for future regional scenario are further discussed. [Display omitted] • Hydrogen production from treated wastewater powered by solar–wind energy is designed. • Multi-objective model is proposed to decide optimal installed capacities and operation. • Proposed solution is feasible and can reduce electricity curtailment and plants' tariff. • A higher renewable energy ratio leads to worse financial performance. • The prospective water usage for future regional scenario is further discussed. [ABSTRACT FROM AUTHOR]

In an era marked by escalating environmental concerns and increasing energy demands, the development of advanced, cost-effective polymer electrolyte membrane (PEM) materials is essential to accelerating the widespread adoption of fuel cell technology as a viable and environmentally sustainable alternative to traditional energy sources. To address this challenge, we integrated a novel hybrid nanofiller—fabricated by directly growing TiO 2 nanoparticles on the surface of multi-walled carbon nanotubes (MWCNTs)—into a readily available, cost-efficient polyaromatic polymer, specifically sulfonated polyethersulfone (sPES). The incorporation of the MWCNTs-TiO 2 nanohybrid resulted in significant improvements in the thermo-mechanical stability, swelling capacity, and transport properties of sPES. Ex-situ through-plane proton conductivity measurements demonstrated a peak value of 5.54 mS/cm at 120 °C and 20% RH for PM 5 , representing a tenfold increase compared to unmodified sPES. This enhancement has ascribed to the synergistic effect of the elongated carbon nanotubes and hygroscopic TiO 2 nanoparticles, which fostered the formation of additional proton-conductive pathways within the sPES, maintaining their activity even under dehydrating conditions. Furthermore, the PM 5 nanocomposite exhibited a remarkable peak power density of 87.2 mW/cm2 in the fuel cell (H 2 /air, 120 °C, 30% RH), exceeding the performance of the Nafion benchmark. • A novel MWCNTs-TiO 2 hybrid filler was tested into sulfonated polyethersulfone (sPES). • Direct growth of TiO 2 nanoparticles on the surface of carbon nanotubes was achieved. • Hybrid nanoparticles enhance thermo-mechanical and transport properties of sPES. • Long CNTs with hygroscopic TiO 2 nanoparticles enabled conductivity of 5.54 mS/cm at 120 °C and 20% RH. • Peak power density of 87.2 mW/cm2 for PM 5 in the fuel cell (H 2 /air, 120 °C, 30% RH). [ABSTRACT FROM AUTHOR]

Hydrogen has become an essential element in the pursuit of sustainable and clean energy solutions. Especially with the fast-paced advancement in demand, supply, and policy environment, its impact on hybrid renewable energy (HRE) management is becoming increasingly relevant. Efficient energy consumption, cost reduction, and enhanced user comfort are now critical factors in energy optimization. The production of green hydrogen, which is generated through water electrolysis using renewable energy sources (RES), has shown great potential as a sustainable energy solution. It offers several advantages, such as zero greenhouse gas emissions, high energy density, and versatile applications. This paper presents a detailed study on the power management and control of a hybrid renewable system (HRES) equipped with a diesel generator (DG) as a backup power source. The main objectives of the hybrid system are to satisfy the load power demand, ensure the most efficient use of the HRES, and keep the battery bank charged to prevent blackouts and extend the battery's life. To guarantee the system's reliability, the DG should be sized to meet the peak load demand when the RES generates less electricity than the load demand. This study explores the feasibility of modified versions of the load following and cycle charging control strategies to overcome the limitations of managing generation and storage systems' operations in different operating modes and to enhance the performance of an HRES with a DG that supplies electricity to a small and remote location. The proposed method not only maximizes the use of RES production but also enables multi-energy source management under different power generation and load demand scenarios. The study's outcomes demonstrate the feasibility of this proposed power dispatch strategy in a remote location environment. The paper includes a detailed discussion of overall control, mathematical models, energy storage in the battery model, and energy dispatching based on load following. To design and simulate the hybrid model system, MATLAB-SIMULINK is used, and the results are analyzed to identify the appropriate operation requirements, component selection, and energy management of the hybrid renewable energy system. [ABSTRACT FROM AUTHOR]

Hydrogen, as a promising renewable energy source, is considered to have significant potential for achieving the dual-carbon goal. In the present study, a 1D engine model is used to investigate the impact of hydrogen injection pressure and its changing law on the performance of hydrogen engines. The results indicate that under low load conditions, increased hydrogen injection pressure from 5 bar to 25 bar initially improved power performance and fuel economy and then declined them; an injection pressure of 10 bar got the highest power of 51.91 kW and thermal efficiency of 43.25%. Under medium load conditions and high load conditions, increased hydrogen injection pressure from 5 bar to 25 bar, power performance and fuel economy declined. The NOx emission of engine declined gradually with the increase of injection pressure from 5 bar to 25 bar. The NOx emission is reduced by approximately 2.5% as the injection pressure is raised from 5 bar to 15 bar, and then, as the injection pressure continues to increase, the reduction becomes less significant. Additionally, selecting the End Peak curve for hydrogen injection pressure change increased indicated power by 0.4 kW, thermal efficiency by 0.2%, and reduces NOx emission by around 8% than other curves. The study also found that near-zero emissions can be achieved when λ value exceeds 2.5. • Different hydrogen injection pressure and its variation law are investigated. • The effects of different hydrogen injection pressures on engine performance are investigated. • The influences of various hydrogen injection pressure variation law on engine performance are investigated. • The near zero emission conditions of the engine are investigated. [ABSTRACT FROM AUTHOR]

The achievement of optimal performance is a crucial aspect of renewable energy resources. The study attempts to boost the power conversion efficiency of polycrystalline silicon (Si) photovoltaic cells by the application of anti-reflective coating (ARC). The solgel method is employed to synthesize yttrium oxide (Y 2 O 3). The electro spraying method was utilized to apply the ARC on photovoltaic cells. The effect of coating on PV cells were determined through the structural, electrical, optical and thermal analysis. The antireflective material was uniformly applied over the coated substrate for 45 min (Y-I), 90 min (Y-II), 135 min (Y-III), and 180 min (Y-IV). The sample coated for 135 min showed an optimal power conversion efficiency (PCE) of 21.65 % and 20.09 % in the presence of neodymium light and direct sunlight, respectively, and a minimum electrical resistivity of 3.96 × 10−3 Ω-cm. In addition, Y-III coated cells exhibit a maximum absorbance of 94 %. The Y-III coated photovoltaic cells demonstrated the lowest temperature of 34.6 °C when exposed to an open environment and 40.6 °C when exposed to a controlled environment. The results from numerous studies demonstrated that Y 2 O 3 can be a suitable ARC, which effectively improved the efficiency of photovoltaic cells. [ABSTRACT FROM AUTHOR]

The energy optimization in smart power grids (SPGs) is crucial for ensuring efficient, sustainable, and cost-effective energy management. However, the uncertainty and stochastic nature of distributed generations (DGs) and loads pose significant challenges to optimization models. In this study, we propose a novel optimization model that addresses these challenges by employing a probabilistic method to model the uncertain behavior of DGs and loads. Our model utilizes the multi-objective wind-driven optimization (MOWDO) technique with fuzzy mechanism to simultaneously address economic, environmental, and comfort concerns in SPGs. Unlike existing models, our approach incorporates a hybrid demand response (HDR), combining price-based and incentive-based DR to mitigate rebound peaks and ensure stable and efficient energy usage. The model also introduces battery energy storage systems (BESS) as environmentally friendly backup sources, reducing reliance on fossil fuels and promoting sustainability. We assess the developed model across various distinct configurations: optimizing operational costs and pollution emissions independently with/without DR, optimizing both operational costs and pollution emissions concurrently with/without DR, and optimizing operational costs, user comfort, and pollution emissions simultaneously with/without DR. The experimental findings reveal that the developed model performs better than the multi-objective bird swarm optimization (MOBSO) algorithm across metrics, including operational cost, user comfort, and pollution emissions. • Presenting a multi-objective model for energy management via day-ahead scheduling in smart grids. • Enhancing day-ahead scheduling with renewables and demand response strategies. • Introducing a probabilistic model for solar and wind energy uncertainty prediction. • Proposing a hybrid demand response to lower peak energy demand and prevent rebound peaks. • Utilizing MOWDO algorithm for optimal Pareto fronts exploration to achieve tri-objective optimization: cost, emissions, and user comfort. [ABSTRACT FROM AUTHOR]

In many different places, wind energy has the potential to solve many challenges. Reducing dependency on distant power networks increases energy security, provides an alternative to energy independence, and advances environmental sustainability as a renewable energy source. Furthermore, the development of wind energy established in these regions improves regional economies and creates possibilities for employment in manufacturing, construction, maintenance, and operation. Landowners might receive more revenue from wind farms through land leasing agreements. Furthermore, wind energy diversifies the energy mix, reducing its vulnerability to fluctuations in energy prices and environmental degradation and decreasing energy expenditures for individuals and companies. Sustainable energy sources are crucial to solving communities' unique energy problems. This study aims to assess Saudi Arabia's wind energy potential. It completes assessments of wind resource availability, site suitability, wind turbine technology, energy output, environmental impact, and economic viability. Statistical techniques such as time series analysis, regression analysis, and probability distributions are utilized to understand and improve wind farm efficiency. [ABSTRACT FROM AUTHOR]

Fully sustainable hydrogen production demands renewable energy sources. This study uses an approach that combines solar photovoltaic (PV) systems with batteries to tailor the energy supply to the unique demands of anion exchange membrane (AEM) electrolyzers. An open source DC-DC adjustable converter is designed, prototyped, and tested to enable an AEM to operate at its optimum efficiency without disrupting the continuous operation of existing loads. A structured operating schedule is simulated to align PV performance with AEM electrolyzer characteristics. The results show the >90% efficiency open-source converter was able to directly power the electrolyzer while taking advantage of solar energy surplus for hydrogen production. By strategically scheduling the electrolyzer to maximize output and minimize waste the system only utilizes excess solar energy. By employing this sustainable method, the study highlights a scalable solution that not only enhances the efficiency of hydrogen production, but also promotes the deployment of PV. • Surplus PV energy is used via structured AEM electrolyzer schedules for H₂ production. • 75% of AEM is PV-powered, reducing energy waste, with batteries covering the rest. • Open-source adjustable DC-DC converter ensures optimal AEM electrolyzer performance. • Custom DC-DC converter achieves 90% efficiency, cutting power loss for the electrolyzer. [ABSTRACT FROM AUTHOR]

While Iran has notable renewable energy potentials, the renewable energy sector of this country has remained underdeveloped, mostly because of easy access to cheap fossil fuels. This paper discusses and analyzed the possibility for hydrogen generation from wind resource in urban city which is suffered from air pollution and is located in northwestern Iran. Wind energy and power density estimations were performed using the 2-parameter Weibull probability distribution function. These estimates were used to predict the power output, hydrogen output, economic viability, and environmental benefit of building a wind power-hydrogen production unit in one of several candidate sites in the studied area. Ultimately, the most suitable site for such a project was determined using the SWARA/WASPAS method. After investigating 16 different conventional wind turbines, the best one in terms of achievable power and hydrogen output and economic feasibility was determined. The results showed that Gamesa G80 with a capacity of 2 GW was the best wind turbine for the urban area. Gardaneh-Almas with a wind power density of 1252W/m2 was identified as the best site for power generation in the region. Potential wind-powered hydrogen output at this site was estimated to 97 ton/yr. LCOE and LCOH for this site were estimated to 0.047 $/kWh and 4.6 $/kg-H 2 , respectively. • Hydrogen production integrated urban area toward sustainable cities are discussed. • 3E analysis of wind energy for hydrogen production (WHP) is investigated. • A multi-aspect analysis of WHP is analyzed by WASPAS. • A sensitive analysis on wind energy integrated hydrogen system is performed. • The results showed the wind-hydrogen system is best solution in Iranian cities. [ABSTRACT FROM AUTHOR]

Renewable energy sources, such as hydrogen play a crucial role in developing sustainable technologies. Hydrogen is one of the best candidates for future energy transition. Today, hydrogen storage techniques have become an important and debated issue in many countries. This study represents the first attempt to prepare CuCr 2 O 4 nanoparticles using two different methods (sol-gel and green) and compare their performance as an electrocatalyst in electrochemical hydrogen storage. The tetragonal crystal structure, spherical shape, purity, and mesoporous features of the sample were studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDS), and Brunauer-Emmett-Teller (BET) techniques. Additionally, the hydrogen storage performance of CuCr 2 O 4 nanoparticles was investigated using cyclic voltammetry (CV), and charge-discharge chronopotentiometry (CP) in a 3 M KOH alkaline medium. The result revealed that the specific capacitance values of CuCr 2 O 4 nanoparticles in sol-gel and green methods were obtained to be 2427 and 1503 Fg-1, respectively. The discharge capacities of CuCr 2 O 4 nanoparticles in sol-gel and green methods after 11 cycles were calculated to be 4304 and 3011 mAh/g, respectively. The superior hydrogen storage capability of CuCr 2 O 4 nanoparticles in the sol-gel method can be attributed to its high porosity. [Display omitted] • CuCr 2 O 4 nanoparticles were synthesized using the sol-gel and green methods. • Study of crystal structure, morphological, and electrochemical properties of the samples. • CuCr 2 O 4 showed excellent hydrogen storage capacity of 4304 and 3011mAh/g in the sol-gel and green methods, respectively. • A promising material for hydrogen storage applications. [ABSTRACT FROM AUTHOR]

Incorporating hydrogen into the natural gas pipeline network (NGPN) plays a key role in absorbing large-scale renewable energy and mitigating the supply-demand contradictions between electricity and natural gas. The gas-electricity integrated energy system (GEIES) using hydrogen as an intermediate carrier is an effective approach for efficient utilization and low-carbon development in the energy sector. To analyze the influence of hydrogen blending on the operation optimization of GEIES, and to study the impact of fluctuating hydrogen supply and different user acceptance on the economic operation of hydrogen-blended GEIES, this paper proposes a gas-electric integrated energy double-way coupling model (GIEDCM), composed of gas turbines, coal-fired units, wind turbines, photovoltaic units, electrolytic cells, and hydrogen storage tanks (HST). The objective function is to minimize system operational costs, establishing a mixed integer nonlinear programming problem considering hydrogen blending. The nonlinear equations are handled using a piecewise linearization method, and the algorithm is solved by the branch-and-bound method and using the GUROBI solver to verify the effectiveness of the algorithm. This ultimately addresses the issue of low utilization of renewable energy sources (RES). Taking the Belgian 20-node NGPN and the IEEE-39-node electric grid system as examples, different scenarios of GEIES operational optimization are analyzed. The optimization results show that natural gas hydrogen blending significantly enhances the utilization level of wind and solar resources, substantially reduces the wastage of RES, and promotes the coupling and complementarity between various energy sources, reducing system operational costs. However, fluctuations in hydrogen supply and changes in user acceptance directly affect the hydrogen content in the NGPN, thereby influencing the hydrogen blending process. Therefore, hydrogen fluctuations should be minimized in the hydrogen mixing process, and if fluctuations are unavoidable, hydrogen should be supplied in intermittent wherever possible. Appropriate improvement of user acceptance can better improve the economic benefits of system operation. • Establish a new GIEDCM considering hydrogen blending. • Piecewise linearization was used to address nonlinearity. • Hydrogen-blended GEIES, hydrogen fluctuation supply, user acceptance. • Hydrogen supply should reduce fluctuations, and appropriately improve user acceptance. • The feasibility and advantages of the present method are verified by comparing with the GUROBI solver. [ABSTRACT FROM AUTHOR]

The trend today is transformation of traditional high-carbon fossil fuel energy to low-carbon clean energy. A promising energy carrier is hydrogen generated from renewable energy sources, providing that hydrogen storage and transportation are the primary important parts of hydrogen energy industrial chain. Efficient and reversible hydrogen storage is of crucial importance in the application of hydrogen energy, and the use of liquid organic hydrogen carriers (LOHC) for hydrogen storage is among technologies under development. Highly effective and low-cost catalysts are of prime importance in the LOHC technology. The present review elucidates the directions and advancements in the development of Pd catalysts for dehydrogenation/hydrogenation of heterocyclic LOHC compounds for the last few years including 2024. The review provides valuable insights into the design and preparation of efficient and durable heterogeneous Pd catalysts for the complete reversible dehydrogenation of hydrogen-rich heterocyclic molecules that are considered as LOHC, which can contribute to technologies based on hydrogen production and storage. Thermodynamic aspects of the use of N-heterocyclic compounds and results of theoretical studies of LOHC processing on Pd catalysts are considered. • Recent 5 years summary on Pd catalysts for H 2 release from heteroaromatic LOHC. • Variation in the catalyst efficiency depending on the Pd state and content is discussed. • Effect of the support nature and reducibility on the catalyst efficiency is analyzed. • Application of catalysts with a low Pd content for different LOHC was shown. • Pd clusters and nanoparticles of 1–4 nm on reducible supports are promising catalysts. [ABSTRACT FROM AUTHOR]

Green hydrogen, produced using renewable energy sources, represents a critical component in the transition to sustainable energy systems due to its clean and versatile nature. This research investigates the dynamic behavior of bubbles within the serpentine flow field of a Proton Exchange Membrane Water Electrolysis (PEMWE) cell, aiming to enhance the understanding of two-phase flow dynamics and improve the efficiency of green hydrogen production. Utilizing the Volume of Fluid (VOF) method, a three-dimensional unsteady model was developed to simulate the flow dynamics at the anode of a PEMWE system. The study explores the transition of bubbles from bubbly flow to slug and annular flow, highlighting the significant impact of bubble formation on mass transport and overall cell performance. The results demonstrate that larger bubbles impede liquid water delivery to reaction sites and cause unstable pressure drops. The investigation also examines the influence of wall contact angles on bubble behavior, revealing that hydrophobic surfaces lead to increased gas coverage and more oxygen accumulation inside the channel, which hinders mass transport. These findings underscore the necessity for optimized flow channel designs and enhanced surface treatments to mitigate bubble coalescence and improve PEMWE performance. [Display omitted] • 3D VOF model simulates two-phase flow in PEMWE anode channels. • Flow patterns affect oxygen distribution and pressure drop in channels. • Annular flow reduces water supply to electrodes, impacting efficiency. • Wall wettability is crucial for bubble dynamics and PEMWE mass transport. • Hydrophilic surfaces aid bubble removal, hydrophobic surfaces cause flow hindering. [ABSTRACT FROM AUTHOR]

Renewable energy sources have been widely installed and operated in power systems, particularly in microgrids in the form of distributed generation units. This issue requires efficient energy management tools which take into account the inherent uncertainties of such energy resources. Thus, this paper presents a stochastic framework aimed at scheduling the renewable energy-based and thermal units in a coordinated way. The generation units comprise fuel cell units with proton exchange membrane known as PEMFC-CHP producing heat and power, concurrently. Moreover, the uncertainties arising from wind and solar power as well as market prices are characterized by deploying scenario-based optimization. The mentioned framework considers storing hydrogen and the model is presented within a stochastic mixed-integer nonlinear programming (MINLP) framework. The resulting problem is simulated on a modified 33-bus distribution network and tackled using the modified marine predators algorithm (MMPA)algorithm. The obtained results indicate that the revenue increases by more than 5% compared to other optimization algorithms. Furthermore, taking into account CHP will increase the total profit of the system by more than 15%. • Proposing optimal management of smart parking considering upscale electricity price with Hydrogen Storage Systems (HSS). • Proposing fuel cell units with proton exchange membrane which generate heat and power simultaneously (PEMFC-CHP). • Optimal coordinated scheduling of renewable energy resources in micro-grids improve objective function. • Suggesting the strategy of storing hydrogen is also considered for PEMFC-CHP units. [ABSTRACT FROM AUTHOR]

The gas-liquid separator serves as a crucial component within AEL integrated with renewable energy sources. It is used to separate gas and lye within the circulating solution, thereby enhancing hydrogen production efficiency and mitigating gas crossover phenomena. However, the separation performance of separators is influenced by fluctuations in processing capacity, attributable to the stochastic nature and volatility of renewable energy. The separation efficiency of gravity gas-liquid separators is investigated in this paper. The separation efficiency is 88.28% (experiment) and 90.0% (simulation). Nevertheless, the ability of gravity gas-liquid separators to sustain great separation performance amidst fluctuations in processing capacity is compromised. Moreover, separation efficiency is diminished with increasing gas content and velocity. A spiral diversion gas-liquid separator is proposed with the separation efficiency is up to 96.4%. The spiral diversion gas-liquid separator proves to be a more suitable choice for AEL integrated with renewable energy sources. • Capacity fluctuation is a characteristic of the AEL. • The separation performance is inevitably affected by capacity fluctuation. • The gravity gas-liquid separator exhibits low separation efficiency. • The spiral diversion gas-liquid separator is adaptable to capacity fluctuation. • The separation performance of spiral diversion gas-liquid separator is 96.4%. [ABSTRACT FROM AUTHOR]

This research presents a comprehensive optimization of green ammonia synthesis in Morocco by leveraging advanced deep learning techniques to maximize the utilization of the country's abundant renewable energy resources. By employing deep learning models such as LSTM and LSTM_adv, we forecast ammonia production over the next decade, improving strategies for production and energy storage. Our findings confirmed the viability of sustainable ammonia production in Dakhla and highlighted its transformative potential for global sustainability goals. Under the optimal scenario of 20 % photovoltaic and 80 % wind energy, the production cost was US$575 per tNH 3 , delivering an energy output of 8916.64 GWh and a daily ammonia production of 2503.36 tNH 3. Shifting to 100 % wind energy further enhances the potential, increasing daily ammonia production to a maximum of 3090 tNH 3 while reducing the production cost to US$376 per tNH 3. These results demonstrate the significant economic and environmental benefits of using renewable energy sources for ammonia production in Morocco. By leveraging a country's abundant wind and solar resources, we can contribute to a sustainable and energy-independent future. [Display omitted] • Optimizes ammonia synthesis using renewable energy sources for a greener future. • Projects daily ammonia output of up to 3090 tNH 3 in various energy scenarios. • Achieves 54% efficiency with competitive costs of $376-$575 per tNH 3. • Forecasts ammonia production over 10 years using deep learning models. • Provides insights for sustainable development and energy use in Morocco. [ABSTRACT FROM AUTHOR]

Hydrogen emerges as a promising solution for Türkiye, offering opportunities to enhance renewable energy production and reduce greenhouse gas emissions. Türkiye has significant potential for green hydrogen production, leveraging its abundant renewable energy resources and lower installation costs for renewable energy-based power plants.This study assesses the impact of capital expenditure (CAPEX) on the Levelized Cost of Hydrogen (LCOH) in Türkiye, focusing on both current and projected costs. The LCOH ranges from $3.79/kgH 2 to $5.11/kgH 2 for low and high CAPEX scenarios, given Türkiye's solar electricity cost of $40.32/MWh in 2024. Looking ahead to 2035, achieving Türkiye's hydrogen cost target of $2.4/kgH 2 will require reducing electricity costs to $31/MWh for low CAPEX and $15.3/MWh for high CAPEX. The current electricity cost of $40.3/MWh is significantly above these targets, highlighting the need for substantial technological advancements and cost-reduction strategies to meet future economic objectives for sustainable hydrogen production. [Display omitted] • Türkiye's LCOH from solar energy is $3.79 to $5.11/kgH2 in 2024. • Solar electricity costs for $2.4/kgH2 by 2035 are $15.3-$31/MWh. • Electrolyzer CAPEX is expected to stabilize for capacities above 100 MW in 2035. [ABSTRACT FROM AUTHOR]

Sediment microbial fuel cells (SMFC) provide scalable power generation, but their low performance is primarily due to poor oxygen reduction reaction (ORR) at cathode. The study aims to improve ORR efficiency by constructing triple-phase interphase (TPI) with multiple hydrophobic polytetrafluoroethylene (PTFE) layers on floating air-cathode. Multiple PTFE layers of 0 (HL0), 1 (HL1), 2 (HL2), 3 (HL3), 4 (HL4), 5 (HL5) and 6 (HL6) are coated on single-sided cathode by brushing method. HL3 generates the highest output current of 204 mA, which is three times higher than control case (HL0). The polarization test shows that HL3 achieves the highest maximum power of 48.88 mW/m2, which corresponds to a 6.8-fold increase compared to HL0 (7.06 mW/m2). HL4 performance improves over time but requires long start-up time before increase in bioelectricity production was achieved. Hydrophobic PTFE layer increases the maximum power density of floating air-cathode, mitigates cathodic limitations and improves SMFC performance. The schematic SMFC reactor with PTFE-based floating air cathode to improve bioelectricity generation. [Display omitted] • Hydrophobic PTFE layers on floating air-cathode improve oxygen reduction reaction. • Multiple PTFE layers were deposited on a single-sided cathode by brushing method. • Highest current output in three PTFE layers with a threefold increase than control. • Multiple PTFE layers increase greatly the maximum power density of SMFC system. • Hydrophobic PTFE layer optimizes cathodic performance and overall SMFC performance. [ABSTRACT FROM AUTHOR]

For fast-tracking climate change response, green hydrogen is key for achieving greenhouse gas neutral energy systems. Especially Sub-Saharan Africa can benefit from it enabling an increased access to clean energy through utilizing its beneficial conditions for renewable energies. However, developing green hydrogen strategies for Sub-Saharan Africa requires highly detailed and consistent information ranging from technical, environmental, economic, and social dimensions, which is currently lacking in literature. Therefore, this paper provides a comprehensive novel approach embedding the required range of disciplines to analyze green hydrogen cost-potentials in Sub-Saharan Africa. This approach stretches from a dedicated land eligibility based on local preferences, a location specific renewable energy simulation, locally derived sustainable groundwater limitations under climate change, an optimization of local hydrogen energy systems, and a socio-economic indicator-based impact analysis. The capability of the approach is shown for case study regions in Sub-Saharan Africa highlighting the need for a unified, interdisciplinary approach. • Unique multidisciplinary approach for green hydrogen cost-potentials. • Local perspective on land and hydrogen use of Sub-Saharan Africa embedded. • Spatially and temporally highly detailed green hydrogen cost-potentials. • Sustainable water supply under climate change endogenously secured. • Indicator-based impact analysis shed light on socio-economic conditions. [ABSTRACT FROM AUTHOR]

The optimal configuration of a hybrid renewable energy system (HRES) is a multi-objective, multi-constraint, nonlinear, high-dimensional complex problem. In this work, the detailed system model and optimization objectives of a novel HRES are established. By integrating the Hypervolume method and the algorithmic framework, an improved Non-dominated Sorting Genetic Algorithm III (NSGA-III) method is proposed, addressing the tendency to degrade the Pareto front through random selection. Finally, the system optimization configurations and operations are analyzed and evaluated. The results indicate that the hydrogen subsystem significantly enhances system reliability and environmental sustainability. The proposed algorithm achieves the highest Pareto front superiority index (SI) value of 82.19%, demonstrating excellent robustness and convergence speed. Analysis of HRES operations reveals a negative correlation between battery capacity and decay, with fuel cell decay minimizing at 1.66% for a 3.5 kW capacity. • A detailed hybrid renewable energy system model for residential use is established. • The optimal Pareto front solution set of HRES configurations has been obtained. • A Hypervolume-improved NSGA-III is proposed with a 3.55% Pareto front improvement. • The coupling attenuation of the dual-energy source is analyzed. [ABSTRACT FROM AUTHOR]

A new trend in the transportation sector globally can be observed in a shift away from gasoline-powered vehicles to Hydrogen-based fuel-cell electric vehicles (FCEVs), aimed at reducing harmful emissions. However, there are challenges in producing hydrogen for vehicle stations related to microgrid design and energy management under uncertain conditions. This research sought to identify the optimum design of an electric microgrid to provide the required energy for electric loads, together with a hydrogen refueling station. The microgrid under study consists of various renewable energy resources (RERs), such as photovoltaic (PV) devices, wind power systems, and hydrogen storage systems. The energy management strategy (EMS) aims to reduce the total costs (investment, operation, replacement, procurement energy costs) considering four uncertain parameters associated with PV panels, FCEVs, wind turbines, and power demand. A three-level EMS is proposed based on testing various solutions: without RERs or a hydrogen energy storage system (Level 1); with RERs and a hydrogen energy storage system (Level 2), with RERs and hydrogen energy storage that includes demand side response (DSR) (Level 3). The results indicate annual cost savings of 1.946 E+06 $ for Level 2 and 2.001 E+06 $ for Level 3, compared to Level 1. • Optimal design of interconnected microgrid for refuel stations of FCEV and electric load. • A three-level stochastic energy management strategy is presented with renewable energy sources. • The energy management is solved with RERs, hydrogen storage and demand side response. • Considering uncertainties of load, FCEV and the generated power of RERs. [ABSTRACT FROM AUTHOR]

Solar energy is one of the renewable and clean energy sources. Accurate solar radiation (SR) estimates are therefore needed in solar energy applications. Firstly, two deep learning models, including gated recurrent unit (GRU) and long short-term memory (LSTM), were developed in this study. Next, a data pre-processing technique named multivariate variational mode decomposition (MVMD) was used to construct the MVMD-GRU and MVMD-LSTM hybrid models. To better test the performance of proposed simple and hybrid models, four stations located in the Illinois State of the USA (i.e., Dixon Springs, Fairfield, Rend Lake, and Carbondale) were considered as the study sites. Whole the simple and hybrid models were established under two different strategies, i.e., local and external. In the local strategy, SR of each location was estimated using the minimum and maximum air temperatures from the same station. While, minimum and maximum air temperatures as well as SR data from the nearby station were utilized in external strategy to estimate SR time series of any target site. Root mean square error (RMSE), mean absolute error (MAE), and coefficient of determination (R2) metrics were used when evaluating the models performances. The overall results revealed that the proposed MVMD-GRU and MVMD-LSTM hybrid models illustrated better SR estimates compared to the simple GRU and LSTM in both the local and external strategies. The values of error metrics obtained for the superior hybrid models (i.e., MVMD-LSTM) during the testing period were as: RMSE = 2.532 MJ/m2.day, MAE = 1.921 MJ/m2.day, R2 = 0.916 at Dixon Springs; RMSE = 2.476 MJ/m2.day, MAE = 1.878 MJ/m2.day, R2 = 0.921 at Fairfield; RMSE = 2.359 MJ/m2.day, MAE = 1.780 MJ/m2.day, R2 = 0.924 at Rend Lake; RMSE = 2.576 MJ/m2.day, MAE = 1.941 MJ/m2.day, R2 = 0.914 at Carbondale. Therefore, the coupled models proposed in this study can be possibly recommended as suitable alternatives to the simple deep learning models with a reliable precision in estimating SR time series. [ABSTRACT FROM AUTHOR]

Optimizing domestic energy use and increasing the efficiency of residential power supply chains depend much on home energy management (HEM) systems. This paper examines the utilization of advanced meta-heuristics, namely the Siberian Tiger Optimization (STO) and Sand Cat Swarm Optimization (SCSO) algorithms, for developing HEM systems. The paper presents an integrated STSC algorithm, enhanced by artificial intelligence, that monitors and optimizes household energy usage. To optimize electricity distribution, this algorithm seeks a compromise between reducing costs and lowering the peak-to-average proportion of power. After extensive simulations, the STSC algorithm outperforms previous meta-heuristics in Peak Average Ratio. It demonstrates the possibility of substantial cost reductions in residential settings, reaching up to 8.5%. This improves the overall efficiency of households' power supply chains. In addition to reducing costs, the STSC algorithm contributes to sustainability objectives by utilizing AI to minimize carbon emissions, including renewable energy sources, and facilitate adaptable demand solutions. This highlights its role in promoting sustainable supply chain practices in energy efficiency. The combined use of STO and SCSO algorithms in the STSC method is a new and innovative development in HEM systems. This study highlights the capacity of AI-driven technologies to effectively and environmentally optimize household energy consumption. [ABSTRACT FROM AUTHOR]

In the Vehicle-to-Grid (V2G) scenario, a multitude of coordinated electric vehicles (EVs) equipped with high-capacity batteries actively participate in power grid dispatching as energy carriers, aiming to achieve a tripartite objective encompassing peak load reduction and valley filling, enhanced utilization of renewable energy sources, and added benefits for electric vehicle owners. To address the existing limitations in the charging–discharging decision-making process for electric vehicles based on V2G, such as the lack of consideration for charging pile constraints, EV profitability, EV transportation timeliness, and high costs associated with central servers, we proposed a reinforcement learning-based Multi-vehicle Joint Routing and Charging–Discharging Decision algorithm (MJRCDD). Firstly, the Markov decision process (MDP) was established to describe the problem, and the route selection and charging–discharging behavior of the vehicle were innovatively integrated in the vehicle action space. Secondly, the multi-vehicle joint route planning and charging–discharging decision problem was solved by multi-agent reinforcement learning. Finally, the effectiveness of MJRCDD was verified by simulation and comparison experiments based on PeMS. [ABSTRACT FROM AUTHOR]

The increasing occurrence of severe vulnerabilities, such as natural catastrophes and man-made attacks, has resulted in a corresponding rise in power outages on a global scale. Given the growing recognition of such exceptional occurrences, there is a pressing need to examine the matters pertaining to resilience and the mitigation of risks. This study presents a comprehensive overview of the current state-of-the-art in power system resiliency, as well as an exploration of the measures required to ensure a sustainable environment.These instances of measures include resilience by enabling localized generation and distribution of electricity,diversification of energy resources, withstanding of severe weather conditions, cyberattacks and enabling communities to proactively address the consequences of power outages. There are multiple approaches to bolstering resiliency, which aim to facilitate recovery from unforeseen circumstances and promote stability in the face of uncertain events. These measures also serve to mitigate the impact of unexpected incidents such as power outages. Integrating unpredictable renewable energy sources like solar and wind power into energy networks is difficult, especially in terms of resilience. Renewable energy output fluctuates owing to weather and time of day, requiring sophisticated grid management, energy storage, and demand-response mechanisms to maintain system balance and resilience. This study elucidates the enhanced principles of power system dependability and resilience, in addition to several ways for establishing a sustainable power ecosystem. It examines the complex dynamics of risk assessment, including equipment failures, natural disasters, and human errors, to determine their likelihood and implications. Moreover, the study thoroughly examines the critical moments that occur after accidents, emphasizing the need of prompt reaction and recovery measures in reducing downtime and restoring regular operations to impacted power networks. This involves determining the fundamental reasons behind the incidents, such as whether they arise from equipment malfunctions, human mistakes, external influences like natural calamities, or cyber assaults. In addition, the report examines the efficacy of current response protocols and emergency procedures in reducing the impact of accidents and restoring regular operations to impacted electrical systems. [ABSTRACT FROM AUTHOR]

Inverter-driven generation units (IDGUs) based on renewable energy sources (RES) are actively integrated into electric power systems (EPSs) as a part of carbon neutrality development vector. RES units based on solar energy (photovoltaic power plants (PvPPs)) connected to hydrogen-based electric energy storage system (EESS) have been being actively introduced recently. For connection of modern PvPPs and hydrogen-based EESS (HESS) to grid electric power converters (EPC) are used. Large-scale implementation of these devices causes changes of EPS dynamic properties due to properties of inverting EPCs and their automatic control systems. To study and analyze these properties mathematical modelling can be used. Software on calculation of electromechanical transients is usually used for modelling transient processes. In such software generic mathematical models are developed and used to calculate transients in EPSs with PvPPs and HESSs. These models have a number of features due to which the full range of processes accompanying implementation of PvPPs and HESSs into weak grids cannot be simulated. The paper proposes an alternative all-mode variant to model these units in EPS. [ABSTRACT FROM AUTHOR]

This paper presents an innovative Fuel Cell Combined Heat and Power (FC–CHP) system designed to enhance energy efficiency in hospital settings. The system primarily utilizes solar energy, captured through photovoltaic (PV) panels, for electricity generation. Excess electricity is directed to an electrolyzer for water electrolysis, producing hydrogen which is stored in high-pressure tanks. This hydrogen serves a dual purpose: it fuels a boiler for heating and hot water needs and powers a fuel cell for additional electricity when solar production is low. The system also features an intelligent energy management system that dynamically allocates electrical energy between immediate consumption, hydrogen production, and storage, while also managing hydrogen release for energy production. This study focuses on optimization using genetic algorithms to optimize key components, including the peak power of photovoltaic panels, the nominal power of the electrolyzer, fuel cell, and storage tank sizes. The objective function minimizes the sum of investment, and electricity costs from the grid, considering a penalty coefficient. This approach ensures optimal use of renewable energy sources, contributing to energy efficiency and sustainability in healthcare facilities. • Investigation of innovative FC Micro combined heat and power unit for energy efficiency in a hospital settings. • Intelligent energy management strategy is proposed basing on the energy need, hydrogen production, release, and storage. • Genetic algorithms is applied for optimal use and storage of energy, increasing energy efficiency and sustainability. [ABSTRACT FROM AUTHOR]

Given the diminishing reserves of fossil fuels, the development of renewable alternative energy sources is of global importance. Photocatalytic hydrogen (H 2) evolution stands out as a promising and cost-effective method to harness sunlight for producing carbon-free H 2 fuel. Recently, two-dimensional (2D) covalent organic frameworks (COFs) have garnered considerable research interest in photocatalysis on account of their exceptional surface area and predictable assembly of diverse molecules with adjustable electronic properties. Herein, six 2D COFs are constructed by topologically assembling phosphorus-alkynyl functional moieties and benzene-based building units, including benzene (COF-1), triazine (COF-2), heptazine (COF-3), triphenyl-benzene (COF-4), triphenyl-triazine (COF-5), and triphenyl-heptazine (COF-6), employing first-principles calculations. Our computational results illustrate that the variation of benzene-based building units significantly regulates the electronic structures of COFs, all of which possess semiconductor properties with tunable bandgaps spanning from 1.56 to 2.56 eV. Of particular importance, COF-1, COF-2, COF-4, COF-5, and COF-6 can spontaneously stimulate the hydrogen evolution reaction (HER) under their own light-induced bias without the need for sacrificial agents and co-catalysts. Among them, COF-4 and COF-5 show the best HER activity without light-induced bias, with ΔG values of 0.02 and −0.01 eV, respectively, whose excellent photocatalytic performance can be ascribed to their appropriate electronic band structures, pronounced optical absorption, and low work functions. This finding offers profound insights for exploring other highly efficient HER photocatalysts. Synopsis: Phosphorus-alkynyl COFs (COF-1, 2, 4, 5, 6), featuring varied benzene-based units, can spontaneously initiate HER under light-induced bias, eliminating the reliance on sacrificial agents or co-catalysts. [Display omitted] • The 2D COFs are constructed by phosphorus-alkynyl moieties and benzene-based units. • Varying the benzene-based units notably modulates the electronic structures of COFs. • COF-1, 2, 4, 5, 6 can spontaneously initiate HER under their own light-induced bias. • COF-4, 5 show superior HER activity in the absence of light-induced bias. [ABSTRACT FROM AUTHOR]

Green hydrogen (GH 2) is produced using renewable energy resources (RERs) such as solar photovoltaic (PV) and wind energy. However, relying solely on a single source, H 2 production systems may encounter challenges due to the intermittent nature, time-of-day variability, and seasonal changes associated with these energies. This paper addresses the assessment of mega-scale solar-wind complementarity and the economic viability of large-scale H 2 production and storage in Algeria, considering various climatic conditions. A techno-economic feasibility analysis is conducted by examining various factors, including resource complementarity, electricity and hydrogen productivity, solar and wind contributions, capacity factors (CFs), total net present cost (TNPC), the levelized cost of hydrogen (LCOH) production, and storage (LCOS). The findings reveal that among the studied locations (Tamanrasset, M'sila, Hassi R'mel, and Adrar), Tindouf ranked first in H 2 production, with the highest amount at 11,267 kg and the lowest LCOH at 2.999 $/kg. Wind energy accounted for 69% (3,846,922 kWh) of the total (5,572,571 kWh), while solar energy contributed 31% (1,738,171 kWh). Economically, the LCOH-TNPC for the various locations ranged from 2.99 $/kg-77,042,696 $ to 3.70 $/kg-99,000,488 $. The total electricity-hydrogen generated is estimated at 25,840.251 MWh-529,395 kg. Wind power makes the major contribution, accounting for 63%–70%, compared to the PV system's share, ranging from 31% to 37%. Compared to relying on a single source, leveraging solar-wind complementarity presents opportunities for more consistent energy utilization and reliable hydrogen production. The obtained results are essential for decision-makers and policymakers in Algeria, indicating that the country can successfully achieve energy diversification and transition for future sustainability, and become a major player in the international hydrogen market. [Display omitted] • Mega-scale solar-wind assessment for energy-H 2 production and storage in Algeria. • Feasibility analysis with techno-economic criteria (H 2 productivity, CF, TNPC, LCOH). • LCOH ranges from 2.99 to 3.707 $/kg and TNPC from 77,042,696 to 99,000,488 $. • Tindouf site achieves highest H 2 production and lowest LCOH: 114,267 kg, 2.999 $/kg. • Wind CF is nearly double that of PV, ranging from 34.3 to 44.1%, contributing 63–70%. [ABSTRACT FROM AUTHOR]

In recent times, renewable energy sources have gained significant popularity because of the dwindling reserves of fossil fuels and the significant environmental damage resulting from their use. Among the various renewable energy sources, hydrogen stands out as one of the most crucial technologies for the future. Hydrogen can be produced through several different methods, and electrolysis is among the most frequently used methods. This method employs electrical energy to decompose water into its constituent hydrogen and oxygen molecules. When this electrical energy is derived from renewable sources such as solar or wind, then green hydrogen is produced. Systems that use electrolysis to produce hydrogen are known as electrolyzers. One of the primary challenges in the electrolysis process is ensuring the purity of hydrogen; proper control of the levels and pressures of the gas tanks can improve this purity. Automatic control strategies are very important for regulating the levels and pressures of the oxygen and hydrogen tanks. Researchers have proposed various classical techniques for controller design to mitigate this issue. This study seeks to offer a comprehensive and up-to-date review of existing research on control methods for alkaline electrolyzers, which has attracted considerable attention in recent times. The findings of this review offer valuable insight for future studies aimed at developing new control strategies to enhance hydrogen purity. • Describe main control strategies applied to alkaline electrolyzers. • Comparison of control strategies applied to electrolyzers and finding gaps in the literature. • Describe the importance of hydrogen purity and its production control methods. • Identify applications of alkaline electrolyzers according to the control strategy. • Importance of electrolyzers with renewable energy sources as an energy vector. [ABSTRACT FROM AUTHOR]

This paper examines the problem of synthesizing a two-loop control system for a three-phase voltage source inverter designed for an autonomous power supply system. This type of DC/AC converters is an essential part of power supply systems with renewable energy sources as primary sources, and, accordingly, must corresponds to the requirements for the electric power quality. These requirements are met through circuit design solutions, as well as through the construction of high-precision automatic control systems. The system integrates: a hydrogen electrolyzer, a hydrogen storage system, and a hydrogen fuel cell. The paper proposes a method for calculating the parameters of PI controllers with resonant components, based on the time-scale separation method and allowing independent adjustment of the controller components. The introduction of a resonant component ensures high tracking accuracy for a desired main voltage harmonic and selective suppression of external harmonic influences. The proposed approach allows to synthesize an automatic control system that significantly improves the quality of the voltage inverter output parameters. [ABSTRACT FROM AUTHOR]

High temperature electrolysis of water using solid oxide electrochemical cells (SOEC) is a promising technology for hydrogen production with high energy efficiency and may promote decarbonization when coupled with renewable energy sources and excess heat from nuclear reactors. Apart from the technoeconomic considerations, commercial deployment of this technology critically depends on the long-term performance and durability of SOEC cells/stacks, especially under dynamic operations to withstand the intermittency of renewable energy. Herein, SOEC operation was conducted under galvanodynamic conditions and compared with galvanostatic cells to examine the effect on degradation behavior at an average current density of −0.75 A cm−2 at 750 °C. While dynamic operation shows no significant impact on the overall degradation rates compared to constant current operation, minor performance improvement was observed at potentials above 1.5 V when switched to galvanodynamic mode. The relatively lower overpotential during dynamic operation could not be explained by the negligible changes in the electrochemical impedance or cell temperature. Multiphysics modeling reveals that the oxygen partial pressure (P O2) in the electrolyte oscillates with the alternating current density under dynamic operations. The minor improvement in cell performance under dynamic mode might be associated with the relatively lower P O2 buildup as compared with that under galvanostatic operation. In addition, dynamic operation at high frequencies could effectively lower the extreme P O2 in the electrolyte, thus relieving stresses in the cells and alleviating cell degradation. [Display omitted] • P O2 buildup is major cause of SOEC degradation under current driven operation. • Multiscale modeling shows dynamic operation can alleviate P O2 buildup. • Dynamic operation shows stability and minor performance improvement. • Thermal imaging setup confirms consistency in cell temperature. • Modeling results suggest greater benefit at higher frequency/current. [ABSTRACT FROM AUTHOR]

In this work, the binder-free Fe-doped cobalt LDH/nickel foam (CoFe LDH/NF) electrode was prepared using the hydrothermal method. To achieve higher electrocatalyst activity of CoFe LDH/NF, sulfurization was conducted using the hydrothermal method, while the phosphidation was performed through a chemical vapor deposition (CVD) technique. The CoFeS/NF and CoFeP/NF electrodes exhibited significantly higher electrocatalytic activity than CoFe LDH/NF electrode. The CoFeP/NF electrode with a specific surface area of 6.8 m2 g−1 had lower overpotentials of 120 and 236 mV for hydrogen (HER) and oxygen (OER) evolution reactions, respectively. Additionally, the CoFeP/NF electrode exhibited a low potential of 1.32 V vs. RHE at a current density of 10 mA cm−2 for urea oxidation reaction (UOR). The CoFeP/NF electrode demonstrated low overpotentials of 224 and 273 mV in a seawater solution for HER and OER, respectively. The density functional theory (DFT) calculations confirmed the experimental results in which the CoFeP/NF material had promising electrocatalytic activity for renewable energy applications. • CoFe LDH/nickel foam electrode was sulfurized and phosphorized for water splitting. • Sheet-like morphology of CoFeP and CoFeS materials was similar to CoFe LDH. • CoFeP/NF showed higher water splitting performance than the CoFeS/NF electrode. [ABSTRACT FROM AUTHOR]

Can Norway be an important hydrogen exporter to the European Union (EU) by 2030? We explore three scenarios in which Norway's hydrogen export market may develop: A Business-as-usual, B Moderate Onshore, C Accelerated Offshore. Applying a sector-coupled energy system model, we examine the techno-economic viability, spatial and socio-economic considerations for blue and green hydrogen export in the form of ammonia by ship. Our results estimate the costs of low-carbon hydrogen to be 3.5–7.3€/kg hydrogen. While Norway may be cost-competitive in blue hydrogen exports to the EU, its sustainability is limited by the reliance on natural gas and the nascent infrastructure for carbon transport and storage. For green hydrogen exports, Norway may leverage its strong relations with the EU, but is less cost-competitive than countries like Chile and Morocco, which benefit from cheaper solar power. For all scenarios, significant land use is needed to generate enough renewable energy. Developing a green hydrogen-based export market requires policy support and strategic investments in technology, infrastructure and stakeholder engagement, ensuring a more equitable distribution of renewable installations across Norway and national security in the north. Using carbon capture and storage technologies and offshore wind to decarbonise the offshore platforms is a win-win solution that would leave more electricity for developing new industries and demonstrate the economic viability of these technologies. Finally, for Norway to become a key hydrogen exporter to the EU will require a balanced approach that emphasises public acceptance and careful land use management to avoid costly consequences. • Costs range at €3.50–4.23/kg blue hydrogen, or €5.18–7.25/kg green hydrogen. • Norway has a price advantage over global suppliers for blue hydrogen export to the EU. • Norwegian green hydrogen may be undercut by global suppliers with cheaper electricity. • Offshore wind-based hydrogen is more politically acceptable, but is more expensive. • Balancing blue and green hydrogen exports involves short- and long-term trade-offs. [ABSTRACT FROM AUTHOR]

Research on sustainable energy sources is crucial for alleviating environmental issues and addressing energy security concerns. This study investigates the utilization of various silk precursors in the hydrogen evolution reaction. Waste silk fabric, regenerated silk fibroin film, porous silk fibroin, silk cocoon and degummed silk fibroin were used as precursors to prepare HER electrocatalysts. To investigate the influence of precursor form on catalytic perform9ance, a comparative analysis of the morphology, structure and composition of different materials was conducted. Among various catalysts, waste silk fabric based catalysts exhibit the most excellent catalytic activity, with an overpotential of 113 mV at 10 mA cm−2 and a Tafel slope of 30.9 mV/dec. Even After 1000 cycles of testing, it still maintains excellent catalytic activity. This study provides insights into the influence of precursor forms on the electrochemical performance of biomass carbon-based catalysts, aiming to inspire further research in this field. • Different precursors can exhibit different structures and properties. • NiCo 2 S 4 demonstrates effective bonding capabilities with diverse precursors. • NiCo 2 S 4 exhibits optimal catalytic activity when combined with WS. • The optimal HER overpotential and C dl are 113 mV and 22.46 mF cm−2, respectively. [ABSTRACT FROM AUTHOR]

In this study, a techno-economic analysis tool for conducting detailed feasibility studies on the deployment of green hydrogen hubs for fuel cell bus fleets is developed. The study evaluates and compares five green hydrogen hub configurations' operational and economic performance under a typical metropolitan bus fleet refuelling schedule. Each configuration differs based on its electricity sourcing characteristics such as the mix of energy sources, capacity sizing, financial structure, and grid interaction. A detailed comparative analysis of distinct green hydrogen hub configurations for decarbonising a fleet of fuel-cell buses is conducted. Among the key findings is that a hybrid renewable electricity source and hydrogen storage are essential for cost-optimal operation across all configurations. Furthermore, bi-directional grid-interactive configurations are the most cost-efficient and can benefit the electricity grid by flattening the duck curve. Lastly, the paper highlights the potential for cost reduction when the fleet refuelling schedule is co-optimized with the green hydrogen hub electricity supply configuration. • Techno-economic analysis tool for a green hydrogen hub is developed. • Comparative analysis of five electricity supply configurations. • Comparison of green hydrogen economics across 5 cities in Europe. • Influence of Capex, wholesale electricity prices, and PPA price on LCOH. • A hybrid photovoltaic-wind-grid system with hydrogen storage is cost-optimal. [ABSTRACT FROM AUTHOR]

With the increasing depletion of fossil fuels, hydrogen has attracted much attention as one of the promising alternative energy sources. However, the large-scale application of hydrogen energy still has many challenges, such as insufficient storage, transportation, and demand. Among the various hydrogen storage media, methylcyclohexane (MCH) is regarded as a potential hydrogen storage technology, because of its unique and excellent safety performance, hydrogen storage capacity, physical and chemical properties, and other notable characteristics. Herein, the paper focuses on the current research progress of dehydrogenation technology, which is discussed in term of the reaction mechanism of MCH dehydrogenation, the research progress of catalysts, and the optimization of process conditions, respectively. Subsequently, a summary is provided to point out the possible reaction network diagrams. Additionally, based on the challenges associated with sourcing heat for applications, we propose a novel dual internal combustion engine drive method for hydrogen production from MCH, this innovative approach is expected to propel the advancement and application of hydrogen energy technology. Then, this work concludes with a brief overview of the current research progress in hydrogenation technology. Finally, it summarizes the present challenges of MCH dehydrogenation, and further research of MCH dehydrogenation have prospected in terms of optimal design theory, preparation of novel catalysts, reduction of energy consumption, reactor enhancement, and system coupling. [Display omitted] • The reaction mechanism of MCH dehydrogenation is explored and analyzed. • A network diagram of possible MCH dehydrogenation reactions is summarized. • Progress in the research of active centers, additives, and supports of the catalysts is discussed. • A novel dual internal combustion engine drive method for hydrogen production from MCH is proposed. • The developments, challenges, and prospects for MCH dehydrogenation are reviewed. [ABSTRACT FROM AUTHOR]

Adopting experience and best practices for stimulating the development of RES in individual regions that most successfully implement RES-based installations into their energy balance is a necessary element in the development of the energy sector of disadvantaged regions, while a methodology is needed to determine what factors influenced the success of implementation and what criteria should be used to compare and to determine the success of the implementation of RES in the region, however, a generally accepted methodology has not been formed to date. It was proposed to determine the leading regions and disadvantaged regions from the point of view of success in introducing renewable energy sources into the regional energy system based on the success of fulfilling the regional demand. To assess the success of the use and implementation of installations based on renewable energy in the regional energy system, it is necessary to identify parameters that reflect the potential of renewable energy sources, the initial state of energy supply in the region, the costs of construction of the installation, the profit received from the sale of generated energy, and the current state of the regional energy system. Based on the developed technique, the six most energy-intensive regions included in the operating area of the Southern Branch of United Dispatch Control Center of Russian Power System Operator which have renewable energy power plants were analyzed. The chosen indicator was the share of energy resources generated from renewable energy sources in the total amount of energy resources. Based on the results of the analysis, recommendations were drawn for disadvantaged regions. Energy donation for disadvantaged areas is proposed through the production of a universal energy carrier - hydrogen - in prosperous areas. For energy storage, hydrogen cryogenic storage facilities have been considered promising. The standard cryogenic hydrogen tank RSV-1400 was adopted as part of the main element of the hydrogen storage facility. The capacity of such tanks is 1 000 000 L. To transport energy to consumers, the possibilities of transporting hydrogen by cryogenic tankers and hydrogen transport tanks have been considered. In addition, at present there is a fairly large scientific, technical and practical base for the creation of gas and cryogenic liquid hydrogen pipelines. [ABSTRACT FROM AUTHOR]

Current trends in industries related to autonomous, mobile objects, such as aircraft manufacturing, are aimed at increasing the share of electrification or completely replacing all units in favor of electric ones. Replacing components and assemblies with fully electric ones corresponds to the concept of a fully electric aircraft, which is based on new power sources and sources of electric propulsion, such as lithium-ion batteries, hydrogen batteries, and sources based on renewable energy. At the same time, the requirements for energy efficiency and weight and size parameters of components and assemblies are increasing. These needs can be met through the multi-purpose use of equipment, as well as through new systems that combine a number of functions. The article discusses the use of an aircraft three-stage synchronous generator as a starting device for a gas turbine engine. The problems associated with the use of a three-stage generator are analyzed and a method for solving them is proposed. The article presents a method for creating a starting torque using the reactive component of the electromagnetic torque for a synchronous salient pole generator. The analysis was carried out from the point of view of the formation of electromagnetic torque in an aircraft generator using a voltage inverter. A generalized expression for the torque is obtained, regulated and controlled by the electrical parameters of the frequency converter. [ABSTRACT FROM AUTHOR]

Currently, the proportion of distributed renewable energy sources in distribution networks is continuously increasing, while electric vehicles (pure electric and hydrogen-powered) are experiencing substantial growth within the transportation network. Addressing how to coordinate the regulation of renewable power generation and guide electric vehicle charging, thereby ensuring secure distribution network operations and enhancing traffic network efficiency, has become an urgent issue. This paper proposes a novel strategy for coordinated regulating the coupled system through adjusting hydrogen flow via a joint electricity price–hydrogen price–charging price mechanism. Electricity prices serve to control the electrical energy flow; hydrogen prices control the hydrogen energy flow; and charging prices control the charging patterns of electric vehicles. Two pricing mechanisms are compared: one considering only electricity prices and charging prices (without hydrogen energy flow), and another incorporating electricity prices, hydrogen prices, and charging prices (with hydrogen energy flow). Based on these pricing mechanisms, two methods are contrasted: a rule-based price updating approach and a reinforcement learning-based DDPG (Deep Deterministic Policy Gradient) price decision method. Results show that in the proposed price mechanism (with hydrogen energy flow) DDPG strategy, the voltage deviation has decreased by 0.007 (p.u.) compared to the old price mechanism (without hydrogen energy flow) rule-based strategy. However, there is no significant improvement observed in terms of transportation network regulation capability, in the proposed price mechanism DDPG strategy, the waiting time and time loss have increased by 2.2% and 1.2% compared to the old price mechanism rule-based strategy. Results reveal that the proposed joint electricity price–hydrogen price–charging price mechanism exhibits superior performance, which can effectively control the electrical energy flow-hydrogen energy flow-traffic flow. However different coupling devices exhibit varying degrees of sensitivity to price changes. In addition, the DDPG method proves more effective. In future research, the main focus is on addressing the insufficient explainability of deep reinforcement learning. [Display omitted] • Adjusting hydrogen flow via electricity price–hydrogen price–charging price. • Mathematics formulation of the novel strategy considering hydrogen flow. • The novel strategy can control the electrical-hydrogen-traffic flow. • Different coupling devices exhibit varying degrees of sensitivity to price changes. • DDPG price decision method can reduce the voltage deviations. [ABSTRACT FROM AUTHOR]

Fossil fuels are deemed to diminish because of their limited availability, no renewability, and emissions of greenhouse gases and other poisonous materials to the atmosphere and the ecosystem. Renewable energy based on sustainable biomass has occupied an increasing share of the energy system over the past decade. Among several massively cultivated crops worldwide, corn, sugarcane bagasse, and soybean straws are some of the leading agricultural by-products that can generate substantial energy (e.g., biofuels, hydrogen) as vital sustainable energy to substitute non-renewable fossil fuels. This paper aims to review recent progress in renewable energy generation from biomass based on thermochemical techniques-i.e., gasification, pyrolysis, and liquefaction-detailed technical features and their application for extraction energy from biomass. The quality, composition, and productivity of renewable energy extracted from biomass based on existing thermochemical techniques are compared, and their technical dependencies upon the thermochemical processes are discussed. Furthermore, analysis of technical deficiencies of existing methods, and exploration of innovative emerging technologies for high-efficiency and high-quality renewable energy generation from biomass straws. In general, biomass gasification stands out as the most efficient technique for hydrogen production (HP) from biomass due to mature technology, high hydrogen yield, and potential for integration with other presented techniques. [Display omitted] • A detailed review of HP from biomass using thermochemical techniques. • Discussion about gasification, pyrolysis, and liquefication working principles. • Comparison between all types of presented thermal techniques. • Advantages and disadvantages of gasification, pyrolysis, and liquefication. • Overall performance of all thermal techniques presented in this review. [ABSTRACT FROM AUTHOR]

This work examines the diverse strengths and weaknesses of North African countries in exploiting their renewable energy potential and adopting green hydrogen initiatives. The study focuses on Morocco, Algeria, Tunisia, Egypt, and Mauritania and highlights their respective contributions and challenges in the context of renewable energy and green hydrogen production. It examines Morocco's remarkable achievements in renewable energy, Algeria's potential for economic diversification, Tunisia's commitment to sustainability, Egypt's regional leadership, and the emerging role of Mauritania. The policy and regulatory landscape is assessed, highlighting the need for legal frameworks to support green hydrogen initiatives. Each country's unique approach to green hydrogen as well as their roadmaps and strategies are discussed, highlighting the importance of international collaborations and research and development. Additionally, the report looks at the evolving energy infrastructure and highlights the potential for transporting hydrogen from North Africa to Europe, including adapting existing pipelines and building new pipelines. [Display omitted] • Policies and the progress of green hydrogen projects have been assessed. • Green hydrogen represents a transformative technology for the North African region. • Morocco and Egypt appear to be the most advanced countries. • The other countries studied are still in the early stages of hydrogen development. [ABSTRACT FROM AUTHOR]

The study examines how sustainable energy transitions can meet freshwater needs in green hydrogen production. It proposes four configurations that combine polymer electrolyte membrane (PEM) water electrolysis with renewable energy-powered desalination methods, capable of both continuous and intermittent operations. This study evaluates the capital expenditure (CAPEX) implications of integrating solar or wind energy with seawater reverse osmosis (SWRO) and multi-effect distillation (MED) desalination to produce green hydrogen. It examines the capacities of renewable energy sources, the effectiveness of energy storage solutions, and the performance of various desalination methods, particularly their combined impact on economic viability and overall project costs. An SWRO system intermittently powered by wind energy is identified as the most cost-effective, reducing CAPEX by 46%. The results emphasize the practical benefits of integrating green desalination with green hydrogen production technologies. [Display omitted] • Introduces cost-efficient green H 2 production via renewable energy and desalination. • Analyzes CAPEX for solar/wind energy with SWRO and MED desalination methods. • Nearly 46% reduced CAPEX for intermittent operation than continuous mode. • Finds wind + SWRO in intermittent mode as most economical for H 2 production. • Highlights minimal CAPEX impact of desalination (<1%) on green H 2 plant costs. [ABSTRACT FROM AUTHOR]