Saudi Arabia

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

The decarbonization of hard-to-abate industries is crucial for keeping global warming to below 2◦C. Green or renewable hydrogen synthesized through water electrolysis has emerged as a sustainable alternative for fossil fuels in energy-intensive sectors such as aluminum cement chemicals steel and transportation. However the scalability of green hydrogen production faces challenges including infrastructure gaps energy losses excessive power consumption and high costs throughout the value chain. Therefore this study analyzes the challenges within the green hydrogen value chain focusing on the development of nascent technologies. Presenting a comprehensive synthesis of contemporary knowledge this study assesses the potential impacts of green hydrogen on hard-to-abate sectors emphasizing the expansion of clean energy infrastructure. Through an exploration of emerging renewable hydrogen technologies the study investigates aspects such as economic feasibility sustainability assessments and the achievement of carbon neutrality. Additionally considerations extend to the potential for large-scale renewable electricity storage and the realization of net-zero goals. The findings of this study suggest that emerging technologies have the potential to significantly increase green hydrogen production offering affordable solutions for decarbonization. The study affirms that global-scale green hydrogen production could satisfy up to 24% of global energy needs by 2050 resulting in the abatement of 60 gigatons of greenhouse gas (GHG) emissions - equivalent to 6% of total cumulative CO2 emission reductions. To comprehensively evaluate the impact of the hydrogen economy on ecosystem decarbonization this article analyzes the feasibility of three business models that emphasize choices for green hydrogen production and delivery. Finally the study proposes potential directions for future research on hydrogen valleys aiming to foster interconnected hydrogen ecosystems.

This review presents a broad exploration of the techno economic evaluation of different technologies utilized in the production of hydrogen from both renewable and non-renewable sources. These encompass methods ranging from extracting hydrogen from fossil fuels or biomass to employing microbial processes electrolysis of water and various thermochemical cycles. A rigorous techno-economic evaluation of hydrogen production technologies can provide a critical cost comparison for future resource allocation priorities and trajectory. This evaluation will have a great impact on future hydrogen production projects and the development of new approaches to reduce overall production costs and make it a cheaper fuel. Different methods of hydrogen production exhibit varying efficiencies and costs: fast pyrolysis can yield up to 45% hydrogen at a cost range of $1.25 to $2.20 per kilogram while gasification operating at temperatures exceeding 750°C faces challenges such as limited small-scale coal production and issues with tar formation in biomass. Steam methane reforming which constitutes 48% of hydrogen output experiences cost fluctuations depending on scale whereas auto-thermal reforming offers higher efficiency albeit at increased costs. Chemical looping shows promise in emissions reduction but encounters economic hurdles and sorptionenhanced reforming achieves over 90% hydrogen but requires CO2 storage. Renewable liquid reforming proves effective and economically viable. Additionally electrolysis methods like PEM aim for costs below $2.30 per kilogram while dark fermentation though cost-effective grapples with efficiency challenges. Overcoming technical economic barriers and managing electricity costs remains crucial for optimizing hydrogen production in a low-carbon future necessitating ongoing research and development efforts.

This paper aims to present an overview of the current state of hydrogen storage methods and materials assess the potential benefits and challenges of various storage techniques and outline future research directions towards achieving effective economical safe and scalable storage solutions. Hydrogen is recognized as a clean secure and costeffective green energy carrier with zero emissions at the point of use offering significant contributions to reaching carbon neutrality goals by 2050. Hydrogen as an energy vector bridges the gap between fossil fuels which produce greenhouse gas emissions global climate change and negatively impact health and renewable energy sources which are often intermittent and lack sustainability. However widespread acceptance of hydrogen as a fuel source is hindered by storage challenges. Crucially the development of compact lightweight safe and cost-effective storage solutions is vital for realizing a hydrogen economy. Various storage methods including compressed gas liquefied hydrogen cryocompressed storage underground storage and solid-state storage (material-based) each present unique advantages and challenges. Literature suggests that compressed hydrogen storage holds promise for mobile applications. However further optimization is desired to resolve concerns such as low volumetric density safety worries and cost. Cryo-compressed hydrogen storage also is seen as optimal for storing hydrogen onboard and offers notable benefits for storage due to its combination of benefits from compressed gas and liquefied hydrogen storage by tackling issues related to slow refueling boil-off and high energy consumption. Material-based storage methods offer advantages in terms of energy densities safety and weight reduction but challenges remain in achieving optimal stability and capacities. Both physical and material-based storage approaches are being researched in parallel to meet diverse hydrogen application needs. Currently no single storage method is universally efficient robust and economical for every sector especially for transportation to use hydrogen as a fuel with each method having its own advantages and limitations. Moreover future research should focus on developing novel materials and engineering approaches in order to overcome existing limitations provide higher energy density than compressed hydrogen and cryo-compressed hydrogen storage at 70 MPa enhance costeffectiveness and accelerate the deployment of hydrogen as a clean energy vector.

Climate change is projected to have substantial economic social and environmental impacts worldwide. Currently the leading solutions for hydrogen storage are in salt caverns and depleted natural gas reservoirs. However the required geological formations are limited to certain regions. To increase alternatives for hydrogen storage this paper proposes storing hydrogen in pipes filled with gravel in lakes hydropower and pumped hydro storage reservoirs. Hydrogen is insoluble in water non-toxic and does not threaten aquatic life. Results show the levelized cost of hydrogen storage to be 0.17 USD kg−1 at 200 m depth which is competitive with other large scale hydrogen storage options. Storing hydrogen in lakes hydropower and pumped hydro storage reservoirs increases the alternatives for storing hydrogen and might support the development of a hydrogen economy in the future. The global potential for hydrogen storage in reservoirs and lakes is 3 and 12 PWh respectively. Hydrogen storage in lakes and reservoirs can support the development of a hydrogen economy in the future by providing abundant and cheap hydrogen storage.

The global energy sector is undergoing a transition towards sustainable sources with hydrogen emerging as a promising alternative due to its high energy content and clean-burning properties. The integration of hydrogen into the energy landscape represents a significant advancement towards a cleaner greener future. This paper introduces an innovative decision support system (DSS) that combines multi-criteria decision-making (MCDM) and decision tree methodologies to optimize hydrogen production decisions in emerging economies using Saudi Arabia as a case study. The proposed DSS developed using MATLAB Web App Designer tools evaluates various scenarios related to demand and supply cost and profit margins policy implications and environmental impacts with the goal of balancing economic viability and ecological responsibility. The study's findings highlight the potential of this DSS to guide policymakers and industry stakeholders in making informed scalable and flexible hydrogen production decisions that align with sustainable development goals. The novel DSS framework integrates two key influencing factors technical and logistical by considering components such as data management modeling analysis and decision-making. The analysis component employs statistical and economic methods to model and assess the costs and benefits of eleven strategic scenarios while the decision-making component uses these results to determine the most effective strategies for implementing hydrogen production to minimize risks and uncertainties.

This paper mainly focuses on the optimal design of a grid-dependent and off-grid hybrid renewable energy system (RES). This system consists of Photovoltaic (PV) Wind Turbine (WT) as well as Fuel Cell (FC) with hydrogen gas tank for storing the energy in the chemical form. The optimal components sizes of the proposed hybrid generating system are achieved using a novel metaheuristic optimization technique. This optimization technique called Improved Artificial Ecosystem Optimization (IAEO) is proposed for enhancing the performance of the conventional Artificial Ecosystem Optimization (AEO) algorithm. The IAEO improves the convergence trends of the original AEO gives the best minimum objective function reaches the optimal solution after a few iterations numbers as well as reduces the falling into the local optima. The proposed IAEO algorithm for solving the multiobjective optimization problem of minimizing the Cost of Energy (COE) the reliability index presented by the Loss of Power Supply Probability (LPSP) and excess energy under the constraints are considered. The hybrid system is suggested to be located in Ataka region Suez Gulf (latitude 30.0 longitude 32.5) Egypt and the whole lifetime of the suggested case study is 25 years. To ensure the accurateness stability and robustness of the proposed optimization algorithm it is examined on six different configurations representing on-grid and off-grid hybrid RES. For all the studied cases the proposed IAEO algorithm outperforms the original AEO and generates the minimum value of the fitness function in less execution time. Furthermore comprehensive statistical measurements are demonstrated to prove the effectiveness of the proposed algorithm. Also the results obtained by the conventional AEO and IAEO are compared with those obtained by several well-known optimization algorithms Particle Swarm Optimization (PSO) Salp Swarm Algorithm (SSA) and Grey Wolf Optimizer (GWO). Based on the obtained simulation results the proposed IAEO has the best performance among other algorithms and it has successfully positioned itself as a competitor to novel algorithms for tackling the most complicated engineering problems.

Underground hydrogen storage (UHS) in depleted oil and gas fields is pivotal for balancing large-scale renewable-energy systems yet the wettability of reservoir rocks in contact with hydrogen after decades of Enhanced Oil Recovery (EOR) operations remains poorly quantified. This work experimentally investigates how two common EOR legacies cationic surfactant (city-trimethyl-ammonium bromide CTAB) and supercritical carbon dioxide (SC–CO2) flooding alter rock–water–Hydrogen (H2) wettability in carbonate formations. Contact angles were measured on dolomite and limestone rock slabs at 30–75 ◦C and 3.4–17.2 MPa using a high-pressure captive-bubble cell. Crude-oil aging shifted clean dolomite from strongly water-wet (θ ~ 28–29◦) to intermediate-wet (θ ≈ 84◦). Subsequent immersion in dilute CTAB solutions (0.5–2 wt %) fully reversed this effect restoring or surpassing the original water-wetness (θ ≈ 21–28◦). Limestone samples exposed to SC-CO2 at 60–80 ◦C became more hydrophilic (θ ≈ 18–30◦) relative to untreated controls; moderate carbonate dissolution (≤6 × 103 ppm Ca2+) produced the most significant improvement in water-wetness whereas severe dissolution yielded diminishing returns. These findings show that many mature reservoirs are already water-wet (post-CO2) or can be easily re-wetted (via residual CTAB). Across all scenarios sample wettability showed little sensitivity to pressure but higher temperature consistently promoted stronger water-wetness. Future work should include dynamic core-flooding experiments with realistic reservoir.

This perspective sheds light on emerging research priorities crucial for advancing the low-carbon hydrogen sector considered critical for achieving net zero greenhouse gas emissions targets especially for hard-to-abate sectors. Our analysis follows a five-step process including drawing from news media academic discourse and expert consultations. We identify twenty-one major research challenges. Among the top priorities highlighted by experts are: (i) Evaluating the trade-offs of hydrogen-fueled power generation compared to hydrocarbon fuels and renewables with alternative storage solutions and the feasibility of co-firing hydrogen and ammonia with hydrocarbon fuels for backup or independent power generation; (ii) Exploring how global hydrogen trade could be shaped by market forces such as price volatility geopolitical dynamics and international collaborations; (iii) Examining the financial considerations for investors from developed nations pursuing hydrogen projects in resource-rich developing countries balancing costs investment risks and expected returns. We find statistically significant differences in opinions on hydrogen/ammonia co-firing for power generation between experts from China and those from the U.S. and Germany.

This paper presents the design and implementation of an Intelligent Home Energy Management System in a smart home. The system is based on an economically decentralized hybrid concept that includes photovoltaic technology a proton exchange membrane fuel cell and a hydrogen refueling station which together provide a reliable secure and clean power supply for smart homes. The proposed design enables power transfer between Vehicle-to-Home (V2H) and Home-to-Vehicle (H2V) systems allowing electric vehicles to function as mobile energy storage devices at the grid level facilitating a more adaptable and autonomous network. Our approach employs Double Deep Q-networks for adaptive control and forecasting. A Multi-Agent System coordinates actions between home appliances energy storage systems electric vehicles and hydrogen power devices to ensure effective and cost-saving energy distribution for users of the smart grid. The design validation is carried out through MATLAB/Simulink-based simulations using meteorological data from Tunis. Ultimately the V2H/H2V system enhances the utilization reliability and cost-effectiveness of residential energy systems compared with other management systems and conventional networks.