Saudi Arabia

The high volumetric capacity (53 g H2/L) and its low toxicity and flammability under ambient conditions make formic acid a promising hydrogen energy carrier. Particularly in the past decade significant advancements have been achieved in catalyst development for selective hydrogen generation from formic acid. This Perspective highlights the advantages of this approach with discussions focused on potential applications in the transportation sector together with analysis of technical requirements limitations and costs.

Utilizing renewable energy sources to produce hydrogen is essential for promoting cleaner production and improving power utilization especially considering the growing use of fossil fuels and their impact on the environment. Selecting the most efficient method for distributing power and capacity is a critical issue when developing hybrid systems from scratch. The main objective of this study is to determine how a backup system affects the performance of a microgrid system. The study focuses on power and hydrogen production using renewable energy resources particularly solar and wind. Based on photovoltaics (PVs) wind turbines (WTs) and their combinations including battery storage systems (BSSs) and hydrogen technologies two renewable energy systems were examined. The proposed location for this study is the northwestern coast of Saudi Arabia (KSA). To simulate the optimal size of system components and determine their cost-effective configuration the study utilized the Hybrid Optimization Model for Multiple Energy Resources (HOMER) software (Version 3.16.2). The results showed that when considering the minimum cost of energy (COE) the integration of WTs PVs a battery bank an electrolyzer and a hydrogen tank brought the cost of energy to almost 0.60 USD/kWh in the system A. However without a battery bank the COE increased to 0.72 USD/kWh in the same location because of the capital cost of system components. In addition the results showed that the operational life of the fuel cell decreased significantly in system B due to the high hours of operation which will add additional costs. These results imply that long-term energy storage in off-grid energy systems can be economically benefited by using hydrogen with a backup system.

By 2060 the Kingdom of Saudi Arabia (KSA) aims to achieve net zero greenhouse gas (GHG) emissions targeting 50% renewable energy and reducing 278 million tonnes of CO2 equivalent annually by 2030 under Vision 2030. This ambitious roadmap focuses on economic diversification global engagement and enhanced quality of life. The electricity sector with a 90 GW installed capacity as of 2020 is central to decarbonization aiming for a 55% reduction in emissions by 2030. Saudi Energy Efficiency Centre’s Energy Efficiency Action Plan aims to reduce power intensity by 30% by 2030 while the NEOM project showcases a 4 GW green hydrogen facility reflecting the country’s commitments to sustainability and technological innovation. Despite being the largest oil producer and user Saudi Arabia must align with international CO2 emission reduction targets. Currently there is no state-of-the-art energy policy framework to guide a sustainable energy transition. In the academic literature there is also lack of effort in developing comprehensive energy policy framework. This study provides a thorough and comprehensive analysis of the entire energy industry spanning from the stage of production to consumption incorporating sustainability factors into the wider discussion on energy policy. It establishes a conceptual framework for the energy policy of Saudi Arabia that corresponds with Vision 2030. A total of hundred documents (e.g. 25 original articles and 75 industry reports) were retrieved from Google Scholar Web of Science Core Collection Database and Google Search and then analyzed. Results showed that for advancing the green energy transition areas such as strategies for regional and cross-sectoral collaboration adoption of international models human capital development and public engagement technological innovation and research; and resource conservation environmental protection and climate change should move forward exclusively from an energy policy perspective. This article's main contribution is developing a comprehensive and conceptual policy framework for Saudi Arabia's sustainable green energy transition aligned with Vision 2030. The framework integrates social economic and environmental criteria and provides critical policy implications and research directions for advancing energy policy and sustainable practices in the country.

The reaction of ethylene glycol has been studied over Ag–Pd/TiO2 (anatase) under photo-irradiation while monitoring the reaction products (in the gas and liquid phases) as a function of time and at different partial pressures of molecular oxygen. The catalyst contained metal particles with a mean size of about 1 nm most likely in the form of alloy (TEM STEM and XPS). The complex reaction network involves hydrogen abstraction C-C bond dissociation de-carbonylation and water gas shift ultimately yielding hydrogen and CO2. The two main competing reactions were found to be photo reforming and photo-oxidation. Based on our previous study Ag presence improves the reaction rate for hydrogen production most likely via decreasing the adsorption energy of CO when compared to pure Pd. At high ethylene glycol concentrations the rate of hydrogen produced decreased by a factor of two while changing O2 partial pressure from 0.001 to 0.2 atm. The rate was however very sensitive to oxygen partial pressures at low ethylene glycol concentrations decreasing by about 50 times with increasing oxygen pressures to 1 atm. The order of reaction with respect to O2 changed from near zero at high oxygen partial pressure to ½ at low partial pressure (in 0.008–0.2 atm. range). Liquid phase analysis indicated that the main reaction product was formaldehyde where its concentration was found to be higher than that of H2 and CO2. The mass balance approached near unity only upon the incorporation of formaldehyde and after a prolonged reaction time. This suggests that the photo-reforming reaction was not complete even at prolonged time most likely due to kinetic limitations.

The commercialization of hydrogen as a fuel faces severe technological economic and environmental challenges. As a method to overcome these challenges microalgal biohydrogen production has become the subject of growing research interest. Microalgal biohydrogen can be produced through different metabolic routes the economic considerations of which are largely missing from recent reviews. Thus this review briefly explains the techniques and economics associated with enhancing microalgae-based biohydrogen production. The cost of producing biohydrogen has been estimated to be between $10 GJ-1 and $20 GJ−1 which is not competitive with gasoline ($0.33 GJ−1 ). Even though direct biophotolysis has a sunlight conversion efficiency of over 80% its productivity is sensitive to oxygen and sunlight availability. While the electrochemical processes produce the highest biohydrogen (>90%) fermentation and photobiological processes are more environmentally sustainable. Studies have revealed that the cost of producing biohydrogen is quite high ranging between $2.13 kg−1 and 7.24 kg−1 via direct biophotolysis $1.42kg−1 through indirect biophotolysis and between $7.54 kg−1 and 7.61 kg−1 via fermentation. Therefore low-cost hydrogen production technologies need to be developed to ensure long-term sustainability which requires the optimization of critical experimental parameters microalgal metabolic engineering and genetic modification.

The effect of electrode area electrolyte concentration temperature andlight intensity (up to 218 sun) on PV electrolysis of water is studied using a highconcentrated triple-junction (3-J) photovoltaic cell (PV) connected directly to analkaline membrane electrolyzer (EC). For a given current the voltage requirement torun an electrolyzer increases with a decrease in electrode sizes (4.5 2.0 0.5 and 0.25cm2) due to high current densities. The high current density operation leads to highOhmic losses most probably due to the concentration gradient and bubble formation.The EC operating parameters including the electrolyte concentration and temperaturereduce the voltage requirement by improving the thermodynamics kinetics andtransport properties of the overall electrolysis process. For a direct PV−EC coupling themaximum power point of PV (Pmax) is matched using EC I−V (current−voltage) curvesmeasured for different electrode sizes. A shift in the EC I−V curves toward open-circuitvoltage (Voc) reduces the Pop (operating power) to hydrogen efficiencies due to theincreased voltage losses above the equilibrium water-splitting potential. The solar-to-hydrogen (STH) efficiencies remainedcomparable (∼16%) for all electrode sizes when the operating current (Iop) was similar to the short-circuit current (Isc ) irrespectiveof the operating voltage (Vop) electrolyzer temperature and electrolyte concentration.

The International Maritime Organization (IMO) has set stringent regulations to reduce the carbon footprint of maritime transport using metrics such as the Energy Efficiency Existing Ship Index (EEXI) and Carbon Intensity Indicator (CII) to track progress. This study introduces a novel approach using deep reinforcement learning (DRL) to optimize energy efficiency across five types of vessels: cruise ships car carriers oil tankers bulk carriers and container ships under six different operational scenarios such as varying cargo loads and weather conditions. Traditional fuels like marine gas oil (MGO) and intermediate fuel oil (IFO) challenge compliance with these standards unless engine power restrictions are applied. This approach combines DRL with alternative fuels—bio-LNG and hydrogen—to address these challenges. The DRL algorithm which dynamically adjusts engine parameters demonstrated substantial improvements in optimizing fuel consumption and performance. Results revealed that while using DRL fuel efficiency increased by up to 10% while EEXI values decreased by 8% to 15% and CII ratings improved by 10% to 30% across different scenarios. Specifically under heavy cargo loads the DRL-optimized system achieved a fuel efficiency of 7.2 nmi/ton compared to 6.5 nmi/ton with traditional methods and reduced the EEXI value from 4.2 to 3.86. Additionally the DRL approach consistently outperformed traditional optimization methods demonstrating superior efficiency and lower emissions across all tested scenarios. This study highlights the potential of DRL in advancing maritime energy efficiency and suggests that further research could explore DRL applications to other vessel types and alternative fuels integrating additional machine learning techniques to enhance optimization.

The global energy demand is expected to increase by 30% within the next two decades. Plastic thermochemical recycling is a potential alternative to meet this tremendous demand because of its availability and high heating value. Polypropylene (PP) and polyethylene (PE) are considered in this study because of their substantial worldwide availability in the category of plastic wastes. Two cases were modeled to produce hydrogen from the waste plastics using Aspen Plus®. Case 1 is the base design containing three main processes (plastic gasification syngas conversion and acid gas removal) where the results were validated with the literature. On the other hand case 2 integrates the plastic gasification with steam methane reforming (SMR) to enhance the overall hydrogen production. The two cases were then analyzed in terms of syngas heating values hydrogen production rates energy efficiency greenhouse gas emissions and process economics. The results reveal that case 2 produces 5.6% more hydrogen than case 1. The overall process efficiency was enhanced by 4.13%. Case 2 reduces the CO2 specific emissions by 4.0% and lowers the hydrogen production cost by 29%. This substantial reduction in the H2 production cost confirms the dominance of the integrated model over the standalone plastic gasification model.

In recent years traditional fossil fuels such as coal oil and natural gas have historically dominated various applications but there has been a growing shift towards cleaner alternatives. Among these alternatives hydrogen (H2) stands out as a highly promising substitute for all other conventional fuels. Today hydrogen (H2) is actively taking on a significant role in displacing traditional fuel sources. The utilization of hydrogen in gas turbine (GT) power generation offers a significant advantage in terms of lower greenhouse gas emissions. The performance of hydrogen-based gas turbines is influenced by a range of variables including ambient conditions (temperature and pressure) component efficiency operational parameters and other factors. Additionally incorporating an intercooler into the gas turbine system yields several advantages such as reducing compression work and maintaining power and efficiency. Many scholars and researchers have conducted comprehensive investigations into the components mentioned above within context of gas turbines (GTs). This study provides an extensive examination of the research conducted on hydrogen-powered gas turbine and intercooler with employed different methods and techniques with a specific emphasis on the different case studies of a hydrogen gas turbine and intercooler. Moreover this study not only examined the current state of research on hydrogen-powered gas turbine and intercooler but also covered its influence by offering the effective recommendations and insightful for guiding for future research in this field.

Actually green hydrogen is viewed as a fundamental component in accelerating energy transition and empowering a sustainable future. The current study focuses on the estimation of green hydrogen generation by using wind energy via electrolysis in four sites located in Saudi Arabia. Results showed that the yearly amount of hydrogen that could be generated by using wind turbine ranges between 2542877 kg in Rafha and 3676925 kg in Dhahran. The hydrogen generated could be used to fuel vehicles and decrease the amount of GHG emission from vehicles in KSA. Also hydrogen may be used to store the excess of wind energy and to support the achievement of vision 2030 of the Kingdom. An economic assessment is carried out also in this paper. Results showed that the LCOH by using wind energy in KSA ranges from 2.82 $/kg to 3.81 $/kg.