Turkey

With rising temperatures extreme weather events and environmental challenges there is a strong push towards decarbonization and an emphasis on renewable energy with wind energy emerging as a key player. The concept of multi-energy systems offers an innovative approach to decarbonization with the potential to produce hydrogen as one of the output streams creating another avenue for clean energy production. Hydrogen has significant potential for decarbonizing multiple sectors across buildings transport and industries. This paper explores the integration of wind energy and hydrogen production particularly in areas where clean energy solutions are crucial such as impoverished villages in Africa. It models three systems: distinct configurations of micro-multi-energy systems that generate electricity space cooling hot water and hydrogen using the thermodynamics and cost approach. System 1 combines a wind turbine a hydrogen-producing electrolyzer and a heat pump for cooling and hot water. System 2 integrates this with a biomass-fired reheat-regenerative power cycle to balance out the intermittency of wind power. System 3 incorporates hydrogen production a solid oxide fuel cell for continuous electricity production an absorption cooling system for refrigeration and a heat exchanger for hot water production. These systems are modeled with Engineering Equation Solver and analyzed based on energy and exergy efficiencies and on economic metrics like levelized cost of electricity (LCOE) cooling (LCOC) refrigeration (LCOR) and hydrogen (LCOH) under steady-state conditions. A sensitivity analysis of various parameters is presented to assess the change in performance. Systems were optimized using a multiobjective method with maximizing exergy efficiency and minimizing total product unit cost used as objective functions. The results show that System 1 achieves 79.78 % energy efficiency and 53.94 % exergy efficiency. System 2 achieves efficiencies of 55.26 % and 27.05 % respectively while System 3 attains 78.73 % and 58.51 % respectively. The levelized costs for micro-multi-energy System 1 are LCOE = 0.04993 $/kWh LCOC = 0.004722 $/kWh and LCOH = 0.03328 $/kWh. For System 2 these values are 0.03653 $/kWh 0.003743 $/kWh and 0.03328 $/kWh. In the case of System 3 they are 0.03736 $/kWh 0.004726 $/kWh and 0.03335 $/kWh and LCOR = 0.03309 $/kWh. The results show that the systems modeled here have competitive performance with existing multi-energy systems powered by other renewables. Integrating these systems will further the sustainable and net zero energy system transition especially in rural communities.

In this study the electrical electrochemical and thermodynamic performance of a PV/T electrolyzer system was investigated and the experimental results were verified with a numerical model. The annual amounts of electrical and thermal energy from the PV/T electrolyzer system were calculated as 556.8 kWh and 1912 kWh respectively. In addition the hydrogen production performance for the PV/T electrolyzer was compared with that of a PV electrolyzer system. The amount of hydrogen was calculated as 3.96 kg annually for the PV system while this value was calculated as 4.49 kg for the PV/T system. Furthermore the amount of hydrogen production was calculated as 4.59 kg for a 65 ◦C operation temperature. The electrical thermal and total energy efficiencies of the PV/T system which were obtained hourly on a daily basis were calculated and varied between 12–13.8% 36.1–45.2% and 49.1–58.4% respectively. The hourly exergy analyses were also carried out on a daily basis and the results showed that the exergy efficiencies changed between 13.8–14.32%. The change in the electrolysis voltage was investigated by changing the current and temperature in the ranges of 200–1600 mA/cm2 A and 30–65 ◦C respectively. While the current and the water temperature varied in the ranges of 400–2350 mA/cm2 and 28.1–45.8 ◦C respectively energy efficiency and exergy efficiency were in the ranges of 57.85–69.45% and 71.1–79.7% respectively.

Hydrogen is a promising zero-carbon fuel for internal combustion engines; however the geometric optimization of injectors for low-pressure direct-injection (LPDI) systems under lean-burn conditions remains underexplored. This study presents a high-fidelity optimization framework that couples a validated computational fluid dynamics (CFD) combustion model with a surrogate-assisted multi-objective genetic algorithm (MOGA). The CFD model was validated using particle image velocimetry (PIV) data from non-reacting flow experiments conducted in an optically accessible research engine developed by Sandia National Laboratories ensuring accurate prediction of in-cylinder flow structures. The optimization focused on two critical geometric parameters: injector hole count and injection angle. Partial indicated mean effective pressure (pIMEP) and in-cylinder NOx emissions were selected as conflicting objectives to balance performance and emissions. Adaptive mesh refinement (AMR) was employed to resolve transient in-cylinder flow and combustion dynamics with high spatial accuracy. Among 22 evaluated configurations including both capped and uncapped designs the injector featuring three holes at a 15.24◦ injection angle outperformed the baseline delivering improved mixture uniformity reduced knock tendency and lower NOx emissions. These results demonstrate the potential of geometrybased optimization for advancing hydrogen-fueled LPDI engines toward cleaner and more efficient combustion strategies.

This study seeks to find the appropriate strategies necessary to make sustainable and effective hydrogen energy investments. Within this scope nine different criteria are defined regarding social managerial and financial factors. A hesitant interval-valued intuitionistic fuzzy (IVIF) decision-making trial and evaluation laboratory (DEMATEL) methodology is considered to calculate the degree of importance of the criteria. Additionally impact relation maps are also generated to visualize the causality relationship between the factors. The findings indicate that the technical dimension has the greatest importance in comparison to managerial and financial factors. Furthermore it is also concluded that storage and logistics research and development and technological infrastructure are the most significant factors to be considered when defining hydrogen energy investment strategies. Hence before investing in hydrogen energy necessary actions should be taken to minimize the storage and logistic costs. Among them building the production site close to the usage area will contribute significantly to this purpose. In this way possible losses during the transportation of hydrogen can be minimized. Moreover it is essential to identify the lowest-cost hydrogen storage method by carrying out the necessary research and development activities thereby increasing the sustainability and effectiveness of hydrogen energy investment projects.

Turquoise hydrogen is produced from methane cracking a cleaner alternative to steam methane reforming. This study looks at two proposed systems based on solar methane cracking for low-carbon fuel production. The systems utilize different pathways to convert the hydrogen into a suitable form for transportation and utilize the carbon solid by-product. A direct carbon fuel cell is integrated to utilize the carbon and capture the CO2 emissions. The CO2 generated is utilized for fuel production using CO2 hydrogenation or co-electrolysis. An advanced exergetic analysis is conducted on these systems using Aspen plus simulations of the process. The exergetic efficiency waste exergy ratio exergy destruction ratio exergy recoverability ratio environmental effect factor and the exergetic sustainability index were determined for each system and the subsystems. Solar methane cracking was found to have an environmental effect factor of 0.08 and an exergetic sustainability index of 12.27.

Hydrogen is believed to be the future energy carrier that will reduce environmental pollution and solve the current energy crisis especially when produced from a renewable energy source. Solar energy is a renewable source that has been commonly utilized in the production process of hydrogen for years because it is inexhaustible clean and free. Generally hydrogen is produced by means of a water splitting process mainly electrolysis which requires energy input provided by harvesting solar energy. The proposed model integrates the solar harvesting system into a conventional Rankine cycle producing electrical and thermal power used in domestic applications and hydrogen by high temperature electrolysis (HTE) using a solid oxide steam electrolyzer (SOSE). The model is divided into three subsystems: the solar collector(s) the steam cycle and an electrolysis subsystem where the performance of each subsystem and their effect on the overall efficiency is evaluated thermodynamically using first and second laws. A parametric study investigating the hydrogen production rate upon varying system operating conditions (e.g. solar flux and area of solar collector) is conducted on both parabolic troughs and heliostat fields as potential solar energy harvesters. Results have shown that heliostat-based systems were able to attain optimum performance with an overall thermal efficiency of 27% and a hydrogen production rate of 0.411 kg/s whereas parabolic trough-based systems attained an overall thermal efficiency of 25.35% and produced 0.332 kg/s of hydrogen.

Hydrogen has attracted growing research interest due to its exceptionally high energy per mass content and being a clean energy carrier unlike the widely used hydrocarbon fuels. With the possibility of long-term energy storage and re-electrification hydrogen promises to promote the effective utilization of renewable and sustainable energy resources. Clean hydrogen can be produced through a renewable-powered water electrolysis process. Although alkaline water electrolysis is currently the mature and commercially available electrolysis technology for hydrogen production it has several shortcomings that hinder its integration with intermittent and fluctuating renewable energy sources. The proton exchange membrane water electrolysis (PEMWE) technology has been developed to offer high voltage efficiencies at high current densities. Besides PEMWE cells are characterized by a fast system response to fluctuating renewable power enabling operations at broader partial power load ranges while consistently delivering high-purity hydrogen with low ohmic losses. Recently much effort has been devoted to improving the efficiency performance durability and economy of PEMWE cells. The research activities in this context include investigations of different cell component materials protective coatings and material characterizations as well as the synthesis and analysis of new electrocatalysts for enhanced electrochemical activity and stability with minimized use of noble metals. Further many modeling studies have been reported to analyze cell performance considering cell electrochemistry overvoltage and thermodynamics. Thus it is imperative to review and compile recent research studies covering multiple aspects of PEMWE cells in one literature to present advancements and limitations of this field. This article offers a comprehensive review of the state-of-the-art of PEMWE cells. It compiles recent research on each PEMWE cell component and discusses how the characteristics of these components affect the overall cell performance. In addition the electrochemical activity and stability of various catalyst materials are reviewed. Further the thermodynamics and electrochemistry of electrolytic water splitting are described and inherent cell overvoltage are elucidated. The available literature on PEMWE cell modeling aimed at analyzing the performance of PEMWE cells is compiled. Overall this article provides the advancements in cell components materials electrocatalysts and modeling research for PEMWE to promote the effective utilization of renewable but intermittent and fluctuating energy in the pursuit of a seamless transition to clean energy.

In this study the Bald Eagle Search Algorithm performed hydrogen consumption and battery cycle optimization of a fuel cell electric vehicle. To save time and cost the digital vehicle model created in Matlab/Simulink and validated with real-world driving data is the main platform of the optimization study. The digital vehicle model was run with the minimum and maximum battery charge states determined by the Bald Eagle Search Algorithm and hydrogen consumption and battery cycle values were obtained. By using the algorithm and digital vehicle model together hydrogen consumption was minimized and range was increased. It was aimed to extend the life of the parts by considering the battery cycle. At the same time the number of battery packs was included in the optimization and its effect on consumption was investigated. According to the study results the total hydrogen consumption of the fuel cell electric vehicle decreased by 57.8% in the hybrid driving condition 23.3% with two battery packs and 36.27% with three battery packs in the constant speed driving condition.

This paper aims to holistically study hydrogen production options essential for a sustainable and carbon-free future. This study also outlines the benefits and challenges of hydrogen production methods to provide sustainable alternatives to fossil fuels by meeting the global energy demand and net-zero targets. In this study sixteen hydrogen production methods are selected for sustainability investigation based on seven different criteria. The criteria selected in the comparative evaluation cover various dimensions of hydrogen production in terms of economic technical environmental and thermodynamic aspects for better sustainability. The current study results show that steam methane reforming with carbon capture could provide sustainable hydrogen in the near future while the other technologies’ maturity levels increase and the costs decrease. In the medium- and long-terms photonic and thermal-based hydrogen production methods can be the key to sustainable hydrogen production.

Apart from many limitations the usage of hydrogen in different day-to-day applications have been increasing drastically in recent years. However numerous techniques available to produce hydrogen electrolysis of water is one of the simplest and cost-effective hydrogen production techniques. In this method water is split into hydrogen and oxygen by using external electric current. In this research a novel hydrogen production system incorporated with Photovoltaic – Thermal (PVT) solar collector is developed. The influence of different parameters like solar collector tilt angle thermal collector design and type of heat transfer fluid on the performance of PVT system and hydrogen production system are also discussed. Finally thermal efficiency electrical efficiency and hydrogen production rate have been predicted by using the Adaptive Neuro-Fuzzy Inference System (ANFIS) technique. Based on this study results it can be inferred that the solar collector tilt angle plays a significant role to improve the performance of the electrical and thermal performance of PVT solar system and Hydrogen yield rate. On the other side the spiral-shaped thermal collector with water exhibited better end result than the other hydrogen production systems. The predicted results ANFIS techniques represent an excellent agreement with the experimental results. In consequence it is suggested that the developed ANFIS model can be adopted for further studies to predict the performance of the hydrogen production system.