Publications

The primary motivation of the present study is to mitigate the severe impact of ongoing energy resource shortages while offering clean and sustainable energy carriers such as hydrogen and ammonia. The present system mainly encompasses water splitting and the Haber-Bosch (HB) processes for green hydrogen and ammonia synthesis using solar and wind power respectively. Pointwise quantification analyses are conducted to quantify the power hydrogen and ammonia as well as the economic parameters specifically the levelized cost of energy (LCOE) levelized cost of hydrogen (LCOH) and levelized cost of ammonia (LCOA). This analysis is based on meteorological data from three sites in Egypt considering the specific water and nitrogen requirements for hydrogen and ammonia synthesis respectively. Furthermore carbon dioxide mitigation from solar and wind systems is estimated. These respective sites are Jarjoub on the coastlines of the Mediterranean Sea and Ain Sokhna and Jabal Al-Zait on the coastlines of the Red Sea. The results indicate that the lowest values of LCOE LCOH and LCOA are 12.58 $/MWh 1.91 $/kg H2 and 396.1 $/Ton NH3 respectively which were attained using solar resources at Ain Sokhna geographical site at the Red Sea. Besides Jarjoub which is located in the Mediterranean Sea could attain LCOH of 2.15 $/kg which is still a promising option due to its export potential to Europe. However the use of wind resources is incompetent for solar counterparts in the respective sites; their potential application in Egypt is still promising. The results demonstrate that Jabal Al-Zait stands as a favorable location for green power hydrogen and ammonia synthesis using wind resources which has LCOE LCOH and LCOA of 23.67 $/MWh 2.75 $/kg H2 and 547.8 $/Ton NH3 respectively.

Installing multi-renewable energy (RE) power plants at designated locations known as RE parks is a promising solution to address their intermittent power. This research focuses on optimizing RE parks for three scenarios: photovoltaic (PV)-only wind-only and hybrid PV-wind with the aim of generating green hydrogen in locations with different RE potentials. To ensure rapid response to RE fluctuations a Proton Exchange Membrane (PEM) electrolyzer is employed. Furthermore this research proposes detailed models for manufacturer-provided wind power curves electrolyzer efficiency against its operating power and electrolyzer cost towards its capacity. Two optimization cases are conducted in MATLAB evaluating the optimum sizes of the plants in minimizing levelized cost of hydrogen (LCOH) using classical discrete combinatorial method and determining the ideal PV-to-wind capacity ratio for operating PEM electrolyzer within hybrid PV-wind parks using particle swarm optimization. Numerical simulations show that wind power-based hydrogen production is more cost-effective than PV-only RE parks. The lowest LCOH $4.26/kg H2 and the highest LCOH $14.378/kg H2 are obtained from wind-only and PV-only configurations respectively. Both occurred in Adum-Kirkeby Denmark as it has highest average wind speed and lowest irradiance level. Notably LCOH is reduced with the hybrid PV-wind configuration. The results suggest the optimum PV-to-wind capacity ratio is 65:35 on average and indicate that LCOH is more sensitive to electrolyzer’s cost than to electricity tariff variation. This study highlights two important factors i.e. selecting the suitable location based on the available RE resources and determining the optimum size ratio between the plants within the RE park.

There is a growing interest in green hydrogen with researchers institutions and countries focusing on its development efficiency improvement and cost reduction. This paper explores the concept of green hydrogen and its production process using renewable energy sources in several leading countries including Australia the European Union India Canada China Russia the United States South Korea South Africa Japan and other nations in North Africa. These regions possess significant potential for “green” hydrogen production supporting the transition from fossil fuels to clean energy and promoting environmental sustainability through the electrolysis process a common method of production. The paper also examines the benefits of green hydrogen as a future alternative to fossil fuels highlighting its superior environmental properties with zero net greenhouse gas emissions. Moreover it explores the potential advantages of green hydrogen utilization across various industrial commercial and transportation sectors. The research suggests that green hydrogen can be the fuel of the future when applied correctly in suitable applications with improvements in production and storage techniques as well as enhanced efficiency across multiple domains. Optimization strategies can be employed to maximize efficiency minimize costs and reduce environmental impact in the design and operation of green hydrogen production systems. International cooperation and collaborative efforts are crucial for the development of this technology and the realization of its full benefits.

This paper deals with the optimal scheduling of the resources of a renewable energy community whose coordination is aimed at providing flexibility services to the electrical distribution network. The available resources are renewable generation units battery energy storage systems dispatchable loads and power-to-hydrogen systems. The main purposes behind the proposed strategy are enhancement of self-consumption and hydrogen production from local resources and the maximization of the economic benefits derived from both the selling of hydrogen and the subsidies given to the community for the shared energy. The proposed approach is formulated as an economic problem accounting for the perspectives of both community members and the distribution system operator. In more detail a mixed-integer constrained non-linear optimization problem is formulated. Technical constraints related to the resources and the power flows in the electrical grid are considered. Numerical applications allow for verifying the effectiveness of the procedure. The results show that it is possible to increase self-consumption and the production of green hydrogen while providing flexibility services through the exploitation of community resources in terms of active and reactive power support. More specifically the application of the proposed strategy to different case studies showed that daily revenues of up to EUR 1000 for each MW of renewable energy generation installed can be obtained. This value includes the benefit obtained thanks to the provision of flexibility services which contribute about 58% of the total.

Hydrogen and its derivatives are important components to achieve climate policy goals especially in terms of greenhouse gas neutrality. There is an ongoing controversial debate about the applications in which hydrogen and its derivatives should be used and to what extent. Typically the estimation of hydrogen demand relies on scenario-based analyses with varying underlying assumptions and targets. This study establishes a new framework consisting of existing energy system simulation and optimisation models in order to assess the long-term price-elastic demand of hydrogen. The aim of this work is to shift towards an analysis of the hydrogen demand that is primarily driven by its price. This is done for the case of Germany because of the expected high hydrogen demand for the years 2025–2045. 15 wholesale price pathways were established with final prices in 2045 between 56 €/MWh and 182 €/MWh. The results suggest that – if climate targets are to be achieved - even with high hydrogen prices (252 €/MWh in 2030 and 182 €/MWh in 2045) a significant hydrogen demand in the industry sector and the energy conversion sector is expected to emerge (318 TWh). Furthermore the energy conversion sector has a large share of price sensitive hydrogen demand and therefore its demand strongly increases with lower prices. The road transportation sector will only play a small role in terms of hydrogen demand if prices are low. In the decentralised heating for buildings no relevant demand will be seen over the considered price ranges whereas the centralised supply of heat via heat grids increases as prices fall.

The current transition to renewable energies has motivated research into energy storage using various techniques. Of these electrolysis for pure hydrogen production stands out as hydrogen is a crucial energy vector molecule capable of decarbonizing multiple sectors. However the low efficiency of the electrolysis process presents a major limitation. In this work an electrochemical evaluation of catalyst materials for water splitting under elevated temperature and pressure (ETP) conditions to replicate realistic electrolyzer operating environments is proposed. The NiFeP/Zn-coated nickel foam electrodes demonstrated a brain-like compact morphology with EDS revealing a composition of 62.20 at% Ni 13.90 at% Fe 1.60 at% Zn 7.65 at% P and 15.21 at% O2. Electrochemical performance tests revealed a significant reduction in overpotential for the hydrogen evolution reaction (HER) achieving 38 mV at 8 bar and 80 ◦C while the oxygen evolution reaction (OER) exhibited 119 mV at 1 bar and 80 ◦C both at |30| mAcm− 2 . Chronopotentiometry confirmed the stability of the coating for over 24 h at high current density of |400| mAcm− 2 . The bifunctional capability of the coating was validated in a fullcell test obtaining a remarkably low overpotential of 1.47 V at 30 mAcm− 2 for overall water splitting under 80 ◦C and 8 bar conditions.

Experiments are performed in hydrogen-oxygen mixtures at the cryogenic temperature of 77 K with the equivalence ratio of 1.5 and 2.0. The optical fibers pressure sensors and the smoked foils are used to record the flame velocity overpressure evolution curve and detonation cells respectively. The 1st and 2nd shock waves are captured and they finally merge to form a stronger precursor shock wave prior to the onset of detonation. The cryogenic temperature will cause the larger expansion ratio which results in the occurrence of strong flame acceleration. The stuttering mode the galloping mode and the deflagration mode are observed when the initial pressure decreases from 0.50 atm to 0.20 atm with the equivalence ratio of 1.5 and the detonation limit is within 0.25-0.30 atm. The heat loss effect on the detonation limit is analysed. In addition the regularity of detonation cell is investigated and the larger post-shock specific heat ratio !"" and the lower normalized activation energy # at lower initial pressure will cause the more regular detonation cell. Also the detonation cell width is predicted by a model of = ($) ⋅ Δ# and the prediction results are mainly consistent with the experimental results.

Proton Exchange Membrane (PEM) electrolysis an advanced technique for producing hydrogen with efficiency and environmental friendliness signifies the forefront of progress in this domain. Compared to alkaline cells these electrolytic cells offer numerous advantages such as lower operating temperatures enhanced hydrogen production efficiency and eliminating the need for an aqueous solution. However PEM electrolysis still faces limitations due to the high cost of materials used for the membrane and catalysts resulting in elevated expenses for implementing large-scale systems. The pivotal factor in improving PEM electrolysis lies in the Platinum catalyst present on the membrane surface. Enhancing catalytic efficiency through various methods and advancements holds immense significance for the progress of this technology. This study investigates the use of patterned membranes to improve the performance of PEM electrolytic cells toward green hydrogen production. By increasing the Platinum loading across the membrane surface and enhancing catalytic performance these patterned membranes overcome challenges faced by conventionally fabricated counterparts. The findings of this research indicate that membranes with modified surfaces not only exhibit higher current draw but also achieve elevated rates of hydrogen production.

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.

The aim of this paper is the design and implementation of an advanced model predictive control (MPC) strategy for the management of a wind–solar microgrid (MG) both in the islanded and grid-connected modes. The MG includes energy storage systems (ESSs) and interacts with external hydrogen and electricity consumers as an extra feature. The system participates in two different electricity markets i.e. the daily and real-time markets characterized by different time-scales. Thus a high-layer control (HLC) and a low-layer control (LLC) are developed for the daily market and the real-time market respectively. The sporadic characteristics of renewable energy sources and the variations in load demand are also briefly discussed by proposing a controller based on the stochastic MPC approach. Numerical simulations with real wind and solar generation profiles and spot prices show that the proposed controller optimally manages the ESSs even when there is a deviation between the predicted scenario determined at the HLC and the real-time one managed by the LLC. Finally the strategy is tested on a lab-scale MG set up at Khalifa University Abu Dhabi UAE.