Egypt

In recent times renewable energy systems (RESs) such as Photovoltaic (PV) and wind turbine (WT) are being employed to produce hydrogen. This paper aims to compare the efficiency and performance of PV and WT as sources of RESs to power polymer electrolyte membrane electrolyzer (PEMEL) under different conditions. The study assessed the input/ output power of PV and WT the efficiency of the MPPT controller the calculation of the green hydrogen production rate and the efficiency of each system separately. The study analyzed variable irradiance from 600 to 1000 W/m2 for a PV system and a fixed temperature of 25˚C while for the WT system it considered variable wind speed from 10 to 14 m/s and zero fixed pitch angle. The study demonstrated that the applied controllers were effective fast low computational and highly accurate. The obtained results showed that WT produces twice the PEMEL capacity while the PV system is designed to be equal to the PEMEL capacity. The study serves as a reference for designing PV or WT to feed an electrolyzer. The MATLAB program validated the proposed configurations with their control schemes.

In this study a green hydrogen system was studied to provide electricity for an office building in the Sharjah emirate in the United Arab Emirates. Using a solar PV a fuel cell a diesel generator and battery energy storage; a hybrid green hydrogen energy system was compared to a standard hybrid system (Solar PV a diesel generator and battery energy storage). The results show that both systems adequately provided the power needed for the load of the office building. The cost of the energy for both the basic and green hydrogen energy systems was 0.305 USD/kWh and 0.313 USD/kWh respectively. The cost of the energy for both systems is very similar even though the capital cost of the green hydrogen energy system was the highest value; however the replacement and operational costs of the basic system were higher in comparison to the green hydrogen energy system. Moreover the impact of the basic system in terms of the carbon footprint was more significant when compared with the green hydrogen system. The reduction in carbon dioxide was a 4.6 ratio when compared with the basic system.

Ammonia a molecule that is gaining more interest as a fueling vector has been considered as a candidate to power transport produce energy and support heating applications for decades. However the particular characteristics of the molecule always made it a chemical with low if any benefit once compared to conventional fossil fuels. Still the current need to decarbonize our economy makes the search of new methods crucial to use chemicals such as ammonia that can be produced and employed without incurring in the emission of carbon oxides. Therefore current efforts in this field are leading scientists industries and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector moving through all of the steps in the production distribution utilization safety legal considerations and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes legal barriers that will be faced to achieve its deployment safety and environmental considerations that impose a critical aspect for acceptance and wellbeing and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein this work sets the principles research practicalities and future views of a transition toward a future where ammonia will be a major energy player.

Hydrogen is known to be the carbon-neutral alternative energy carrier with the highest energy density. Currently more than 95% of hydrogen production technologies rely on fossil fuels resulting in greenhouse gas emissions. Water electrolysis is one of the most widely used technologies for hydrogen generation. Nuclear power a renewable energy source can provide the heat needed for the process of steam electrolysis for clean hydrogen production. This review paper analyses the recent progress in hydrogen generation via high-temperature steam electrolysis through solid oxide electrolysis cells using nuclear thermal energy. Protons and oxygen-ions conducting solid oxide electrolysis processes are discussed in this paper. The scope of this review report covers a broad range including the recent advances in material development for each component (i.e. hydrogen electrode oxygen electrode electrolyte interconnect and sealant) degradation mechanisms and countermeasures to mitigate them.

Significant research efforts are directed towards finding new ways to reduce the cost increase efficiency and decrease the environmental impact of power-generation systems. The poly-generation concept is a promising strategy that enables the development of a sustainable power system. Over the past few years the Proton Exchange Membrane Fuel Cell-based Poly-Generation Systems (PEMFC-PGSs) have received accelerated developments due to the low-temperature operation high efficiency and low environmental impact. This paper provides a comprehensive review of the main PEMFC-PGSs including Combined Heat and Power (CHP) co-generation systems Combined Cooling and Power (CCP) co-generation systems Combined Cooling Heat and Power (CCHP) tri-generation systems and Combined Water and Power (CWP) co-generation systems. First the main technologies used in PEMFC-PGSs such as those related to hydrogen production energy storage and Waste Heat Recovery (WHR) etc. are detailed. Then the research progresses on the economic energy and environmental performance of the different PEMFC-PGSs are presented. Also the recent commercialization activities on these systems are highlighted focusing on the leading countries in this field. Furthermore the remaining economic and technical obstacles of these systems along with the future research directions to mitigate them are discussed. The review reveals the potential of the PEMFC-PGS in securing a sustainable future of the power systems. However many economic and technical issues particularly those related to high cost and degradation rate still need to be addressed before unlocking the full benefits of such systems.

The shipping industry is a major enabler of globalization trade commerce and human welfare. But it is still heavily served by fossil fuels which make it one of the foremost greenhouse gas emitting sectors operational today. It is also one of the hardest to abate segments of the transport industry. As part of the economy-wide climate change mitigation and adaptation efforts it is necessary to consider a low carbon energy transition for this segment as well. This study examines the potential role of nuclear power and cogeneration towards greening this sector and identifies the associated techno-commercial and policy challenges associated with the transition. Quantitative estimates of the economics and investments associated with some of the possible routes are also presented. Alternatives such as nuclear-powered ships along commercial maritime trading routes ships working on nuclear derived green hydrogen ammonia or other sustainable power fuels will enable not only decarbonization of the shipping industry but also allow further diversification of the nuclear industry through non-electric applications of nuclear power and new sector coupling opportunities. In the run-up to the UNFCCC-COP28 meeting in 2023 in UAE nuclear equipped nations heavily engaged in and dependent on maritime trade and commerce should definitely consider nuclear driven decarbonization of shipping and some of the options presented here as part of their climate action strategies.

This study provides H2 gas as a renewable energy source from sewage water splitting reaction using a PMT/Au photocathode. So this study has a dual benefit for hydrogen generation; at the same time it removes the contaminations of sewage water. The preparation of the PMT is carried out through the polymerization process from an acid medium. Then the Au sputter was carried out using the sputter device under different times (1 and 2 min) for PMT/Au-1 min and PMT/Au-2min respectively. The complete analyses confirm the chemical structure such as XRD FTIR HNMR SEM and Vis-UV optical analyses. The prepared electrode PMT/Au is used for the hydrogen generation reaction using Na2S2O3 or sewage water as an electrolyte. The PMT crystalline size is 15 nm. The incident photon to current efficiency (IPCE) efficiency increases from 2.3 to 3.6% (at 390 nm) and the number of H2 moles increases from 8.4 to 33.1 mmol h−1 cm−2 for using Na2S2O3 and sewage water as electrolyte respectively. Moreover all the thermodynamic parameters such as activation energy (Ea) enthalpy (∆H*) and entropy (∆S*) were calculated; additionally a simple mechanism is mentioned for the water-splitting reaction.

With the clear adverse impacts of fossil fuel-based energy systems on the climate and environment ever-growing interest and rapid developments are taking place toward full or nearly full dependence on renewable energies in the next few decades. Estonia is a European country with large demands for electricity and thermal energy for district heating. Considering it as the case study this work explores the feasibility and full potential of optimally sized photovoltaic (PV) wind and PV/wind systems equipped with electric and thermal storage to fulfill those demands. Given the large excess energy from 100% renewable energy systems for an entire country this excess is utilized to first meet the district heating demand and then to produce hydrogen fuel. Using simplified models for PV and wind systems and considering polymer electrolyte membrane (PEM) electrolysis a genetic optimizer is employed for scanning Estonia for optimal installation sites of the three systems that maximize the fulfillment of the demand and the supply–demand matching while minimizing the cost of energy. The results demonstrate the feasibility of all systems fully covering the two demands while making a profit compared to selling the excess produced electricity directly. However the PV-driven system showed enormous required system capacity and amounts of excess energy with the limited solar resources in Estonia. The wind system showed relatively closer characteristics to the hybrid system but required a higher storage capacity by 75.77%. The hybrid PV/wind-driven system required a total capacity of 194 GW most of which belong to the wind system. It was also superior concerning the amount (15.05 × 109 tons) and cost (1.42 USD/kg) of the produced green hydrogen. With such full mapping of the installation capacities and techno-economic parameters of the three systems across the country this study can assist policymakers when planning different country-scale cogeneration systems.

Hydrogen is a new promising energy source. Three operating parameters including inlet gas flow rate pH and impeller speed mainly determine the biohydrogen production from membrane bioreactor. The work aims to boost biohydrogen production by determining the optimal values of the control parameters. The proposed methodology contains two parts: modeling and parameter estimation. A robust ANIFS model to simulate a membrane bioreactor has been constructed for the modeling stage. Compared with RMS thanks to ANFIS the RMSE decreased from 2.89 using ANOVA to 0.0183 using ANFIS. Capturing the proper correlation between the inputs and output of the membrane bioreactor process system encourages the constructed ANFIS model to predict the output performance exactly. Then the optimal operating parameters were identified using the honey badger algorithm. During the optimization process inlet gas flow rate pH and impeller speed are used as decision variables whereas the biohydrogen production is the objective function required to be maximum. The integration between ANFIS and HBA boosted the hydrogen production yield from 23.8 L to 25.52 L increasing by 7.22%.

Hydrogen globally recognized as the most efficient and clean energy carrier holds the potential to transform future energy systems through its use as a fuel and chemical resource. Although progress has been made in reversible hydrogen adsorption and release challenges in storage continue to impede widespread adoption. This review explores recent advancements in hydrogen storage materials and synthesis methods emphasizing the role of nanotechnology and innovative synthesis techniques in enhancing storage performance and addressing these challenges to drive progress in the field. The review provides a comprehensive overview of various material classes including metal hydrides complex hydrides carbon materials metal-organic frameworks (MOFs) and porous materials. Over 60 % of reviewed studies focused on metal hydrides and alloys for hydrogen storage. Additionally the impact of nanotechnology on storage performance and the importance of optimizing synthesis parameters to tailor material properties for specific applications are summarized. Various synthesis methods are evaluated with a special emphasis on the role of nanotechnology in improving storage performance. Mechanical milling emerges as a commonly used and cost-effective method for fabricating intermetallic hydrides capable of adjusting hydrogen storage properties. The review also explores hydrogen storage tank embrittlement mechanisms particularly subcritical crack growth and examines the advantages and limitations of different materials for various applications supported by case studies showcasing real-world implementations. The challenges underscore current limitations in hydrogen storage materials highlighting the need for improved storage capacity and kinetics. The review also explores prospects for developing materials with enhanced performance and safety providing a roadmap for ongoing advancements in the field. Key findings and directions for future research in hydrogen storage materials emphasize their critical role in shaping future energy systems.