Publications

This paper delves into the enhancement and optimization of on-grid renewable energy systems using a variety of renewable energy sources with a particular focus on large-scale applications designed to meet the energy demand of a certain load. As global concerns surrounding climate change continue to mount the urgency of replacing traditional fossil fuel-based power generation with cleaner more cost-effective and dependable alternatives becomes increasingly apparent. In this context a comprehensive investigation is conducted on grid connected hybrid energy system that combines photovoltaic wind and fuel cell technologies. The study employs three state-of-the-art optimization algorithms namely Walrus Optimization Algorithm (WaOA) Coati Optimization Algorithm (COA) and Osprey Optimization Algorithm (OOA) to determine the optimal system size and energy management strategies all aimed at minimizing the cost of energy (COE) for grid-based electricity. The results of the optimization process are compared with the results obtained from the utilization of the Particle swarm optimization (PSO) and Grey Wolf optimizer (GWO). The findings of this study underscore both the practical feasibility and the critical importance of adopting on-grid renewable energy systems to decrease the dependence on traditional energy sources within the grid. The proposed WaOA succeeded to reach the optimal solution of the optimal design process with a COE of 0.51758129611 $//kwh while keeping the loss of power supply probability (LPSP) the reliability index at 7.303681e-19. The practical recommendations and forwardlooking insights provided within this research hold the potential to foster sustainable development and effectively mitigate carbon emissions in the future.

Dual fuel combustion has gained attention as a cost-effective solution for reducing the pollutant emissions of internal combustion engines. The typical approach is combining a conventional high-reactivity fossil fuel (diesel fuel) with a sustainable low-reactivity fuel such as bio-methane ethanol or green hydrogen. The last one is particularly interesting as in theory it produces only water and NOx when it burns. However integrating hydrogen into stock diesel engines is far from trivial due to a number of theoretical and practical challenges mainly related to the control of combustion at different loads and speeds. The use of 3D-CFD simulation supported by experimental data appears to be the most effective way to address these issues. This study investigates the hydrogen-diesel dual fuel concept implemented with minimum modifications in a light-duty diesel engine (2.8 L 4-cylinder direct injection with common rail) considering two operating points representing typical partial and full load conditions for a light commercial vehicle or an industrial engine. The numerical analysis explores the effects of progressively replacing diesel fuel with hydrogen up to 80% of the total energy input. The goal is to assess how this substitution affects engine performance and combustion characteristics. The results show that a moderate hydrogen substitution improves brake thermal efficiency while higher substitution rates present quite a severe challenge. To address these issues the diesel fuel injection strategy is optimized under dual fuel operation. The research findings are promising but they also indicate that further investigations are needed at high hydrogen substitution rates in order to exploit the potential of the concept.

In recent years global efforts towards a future with sustainable energy have intensified the development of renewable energy sources (RESs) such as offshore wind solar photovoltaics (PVs) hydro and geothermal. Concurrently green hydrogen produced via water electrolysis using these RESs has been recognized as a promising solution to decarbonizing traditionally hard-to-abate sectors. Furthermore hydrogen storage provides a long-duration energy storage approach to managing the intermittency of RESs which ensures a reliable and stable electricity supply and supports electric grid operations with ancillary services like frequency and voltage regulation. Despite significant progress the hydrogen economy remains nascent with ongoing developments and persistent uncertainties in economic technological and regulatory aspects. This paper provides a comprehensive review of the green hydrogen value chain encompassing production transportation logistics storage methodologies and end-use applications while identifying key research gaps. Particular emphasis is placed on the integration of green hydrogen into both grid-connected and islanded systems with a focus on operational strategies to enhance grid resilience and efficiency over both the long and short terms. Moreover this paper draws on global case studies from pioneering green hydrogen projects to inform strategies that can accelerate the adoption and large-scale deployment of green hydrogen technologies across diverse sectors and geographies.

Morocco despite its heavy reliance on imported fossil fuels which made up 68% of electricity generation in 2020 has recognised its significant renewable energy potential. The Nationally Determined Contribution (NDC) commitment is to reduce emissions by 45.5% from baseline levels with international assistance and abstain from constructing new coal plants. Moreover the Green Hydrogen Roadmap aims to export 10 TWh of green hydrogen by 2030 as well as use it for local electricity storage. This paper critically analyses this Roadmap and Morocco’s readiness to reach its ambitious targets focusing specifically on an energy trilemma perspective and using OSeMOSYS (Open-Source energy Modelling System) for energy modelling. The results reveal that the NDC scenario is only marginally more expensive than the least-cost scenario at around 1.3% (approximately USD 375 million) and facilitates a 23.32% emission reduction by 2050. An important note is the continued reliance on existing coal power plants across all scenarios which challenges both energy security and emissions. The assessment of the Green Hydrogen Scenarios highlights that it could be too costly for the Moroccan government to fund the Green Hydrogen Roadmap at this scale which leads to increased imports of polluting fossil fuels for cost reduction. In fact the emission levels are 39% higher in the green hydrogen exports scenario than in the least-cost scenario. Given these findings it is recommended that the Green Hydrogen Roadmap be re-evaluated with a suggestion for a postponement and reduction in scope.

Hydrogen production and carbon dioxide removal are considered two of the critical pieces to achieve ultimate sustainability target. This study proposes and investigates a new variation of potassium hydroxide thermochemical cycle in order to combine hydrogen production and carbon dioxide removal synergistically. An alkali metal redox thermochemical cycle developed where the potassium hydroxide is considered by using a nonequilibrium reaction. Also the multigeneration options are explored by using two stage steam Rankine cycle multi-effect distillation desalination Li-Br absorption chiller which are integrated with potassium hydroxide thermochemical cycle for hydrogen production carbon capture power generation water desalination and cooling purposes. A comparative assessment under different scenarios is carried out. The energy and exergy efficiencies of the hydrogen production thermochemical cycle are 44.2% and 67.66% when the hydrogen generation reaction is carried out at 180°C and the separation reactor temperature set at 400°C. Among the multigeneration scenarios a trigeneration option of hydrogen power and water indicates the highest energy efficiency as 66.02%.

Offshore green hydrogen emerges as a guiding light in the global pursuit of environmental sustainability and net-zero objectives. The burgeoning expansion of offshore wind power faces significant challenges in grid integration. This avenue towards generating offshore green hydrogen capitalises on its ecological advantages and substantial energy potential to efficiently channel offshore wind power for onshore energy demands. However a substantial research void exists in efficiently integrating offshore wind electricity and green hydrogen. Innovative designs of offshore hydrogen platforms present a promising solution to bridge the gap between offshore wind and hydrogen integration. Surprisingly there is a lack of commercially established offshore platforms dedicated to the hydrogen industry. However the wealth of knowledge from oil and gas platforms contributes valuable insights to hydrogen platform design. Diverging from the conventional decentralised hydrogen units catering to individual turbines this study firstly introduces a pioneering centralised Offshore Green Hydrogen Platform (OGHP) which seamlessly integrates modular production storage and offloading modulars. The modular design of facilitates scalability as wind capacity increases. Through a detailed case study centred around a 100-Megawatt floating wind farm the design process of offshore green hydrogen modulars and its floating sub-structure is elucidated. Stability analysis and hydrodynamic analysis are performed to ensure the safety of the OGHP under the operation conditions. The case study will enhance our understanding OGHP and its modularised components. The conceptual design of modular OGHP offers an alternative solution to ‘‘Power-to-X’’ for offshore renewable energy sector.

In the present study pilot simulations of the phenomena of blast wave and fireball generated by the rupture of a high-pressure (35 MPa) hydrogen tank (volume 72 L) due to fire were carried out. The computational fluid dynamics (CFD) model includes the realizable k-ε model for turbulence and the eddy dissipation model coupled with the one-step chemical reaction mechanism for combustion. The simulation results were compared with experimental data on a stand-alone hydrogen tank rupture in a bonfire test. The simulations provided insights into the interaction between the blast wave propagation and combustion process. The simulated blast wave decay is approximately identical to the experimental data concerning pressure at various distances. Fireball is first ignited at the ground level which is considered to be due to stagnation flow conditions. Subsequently the flame propagates toward the interface between hydrogen and air.

Introduction: The transition towards electrolysis-produced hydrogen in refineries and chemical industries is expected to have a potent impact on the local energy system of which these industries are part. In this study three urban areas with hydrogen-intense industries are studied regarding how the energy system configuration is affected if the expected future hydrogen demand is met in each node individually as compared to forming a “Hydrogen Valley” in which a pipeline can be used to trade hydrogen between the nodes.<br/>Method: A technoeconomic mixed-integer linear optimization model is used to study the investments in and dispatch of the included technologies with an hourly time resolution while minimizing the total system cost. Four cases are investigated based on the availability of offshore wind power and the possibility to invest in a pipeline.<br/>Results: The results show that investments in a pipeline reduces by 4%–7% the total system cost of meeting the demands for electricity heating and hydrogen in the cases investigated. Furthermore investments in a pipeline result in greater utilization of local variable renewable electricity resources as compared to the cases without the possibility to invest in a pipeline.<br/>Discussion: The different characteristics of the local energy systems of the three nodes in local availability of variable renewable electricity grid capacity and available storage options compared to local demands of electricity heating and hydrogen are found to be the driving forces for forming a Hydrogen Valley.

This study evaluates the technoeconomic impacts of direct and indirect electrification on the EU's net-zero emissions target by 2050. By linking the JRC-EU-TIMES long-term energy system model with PLEXOS hourly resolution power system model this research offers a detailed analysis of the interactions between electricity hydrogen and synthetic fuel demand production technologies and their effects on the power sector. It highlights the importance of high temporal resolution power system analysis to capture the synergistic effects of these components often overlooked in isolated studies. Results indicate that direct electrification increases significantly and unimpacted by biomass CCS and nuclear energy assumptions. However indirect electrification in the form of hydrogen varies significantly between 1400 and 2200 TWhH2 by 2050. Synthetic fuels are essential for sector coupling making up 6–12% of total energy consumption by 2050 with the power sector supplying most hydrogen and CO2 for their production. Varying levels of indirect electrification impact electrolysers renewable energy and firm capacities. Higher indirect electrification increases electrolyser capacity factors by 8% leading to more renewable energy curtailment but improves system reliability by reducing 11 TWh unserved energy and increasing flexibility options. These insights inform EU energy policies stressing the need for a balanced approach to electrification biomass use and CCS to achieve a sustainable and reliable net-zero energy system by 2050. We also explore limitations and sensitivities.

To improve the recovery of waste heat and avoid the problem of abandoning wind and solar energy a multi-energy complementary distributed energy system (MECDES) is proposed integrating waste heat and surplus electricity for hydrogen storage. The system comprises a combined cooling heating and power (CCHP) system with a gas engine (GE) solar and wind power generation and miniaturized natural gas hydrogen production equipment (MNGHPE). In this novel system the GE’s waste heat is recycled as water vapor for hydrogen production in the waste heat boiler while surplus electricity from renewable sources powers the MNGHPE. A mathematical model was developed to simulate hydrogen production in three building types: offices hotels and hospitals. Simulation results demonstrate the system’s ability to store waste heat and surplus electricity as hydrogen thereby providing economic benefit energy savings and carbon reduction. Compared with traditional energy supply methods the integrated system achieves maximum energy savings and carbon emission reduction in office buildings with an annual primary energy reduction rate of 49.42–85.10% and an annual carbon emission reduction rate of 34.88–47.00%. The hydrogen production’s profit rate is approximately 70%. If the produced hydrogen is supplied to building through a hydrogen fuel cell the primary energy reduction rate is further decreased by 2.86–3.04% and the carbon emission reduction rate is further decreased by 12.67–14.26%. This research solves the problem of waste heat and surplus energy in MECDESs by the method of hydrogen storage and system integration. The economic benefits energy savings and carbon reduction effects of different building types and different energy allocation scenarios were compared as well as the profitability of hydrogen production and the factors affecting it. This has a positive technical guidance role for the practical application of MECDESs.

The effective storage of hydrogen is a critical challenge that needs to be overcome for it to become a widely used and clean energy source. Various methods exist for storing hydrogen including compression at high pressures liquefaction through extreme cooling (i.e. -253 °C) and storage with chemical compounds. Each method has its own advantages and disadvantages. MAST3RBoost (Maturing the Production Standards of Ultraporous Structures for High Density Hydrogen Storage Bank Operating on Swinging Temperatures and Low Compression) is a European funded Project aiming to establish a reliable benchmark for cold-adsorbed H2 storage (CAH2) at low compression levels (100 bar or below). This is achieved through the development of advanced ultraporous materials suitable for mobility applications such as hydrogen-powered vehicles used in road railway air and water transportation. The MAST3RBoost Project utilizes cutting-edge materials including Activated Carbons (ACs) and high-density MOFs (Metalorganic Frameworks) which are enhanced by Machine Learning techniques. By harnessing these materials the project seeks to create a groundbreaking path towards meeting industry goals. The project aims to develop the world's first adsorption-based demonstrator at a significant kg-scale. To support the design of the storage tank the project employs Computational Fluid Dynamics (CFD) software which allows for numerical investigations. In this paper a preliminary analysis of the tank refilling process is presented with a focus on the impact of the effect of the tank and hydrogen temperatures on quantity of hydrogen adsorbed.

The Paris Agreement aims to limit global warming and one of the most polluting sectors is heavy industry where cement production is a significant contributor. This work briefly explores some alternatives recycling reducing clinker content waste heat recovery and carbon capture discussing their advantages and drawbacks. Then it examines the economic viability and benefits of increasing oxygen concentration in the primary burning air from 21 to 27 vol.% which could improve clinker production by 7% and the production of hydrogen through PEM electrolysis to make up 5% of the fuel thermal fraction considering both in a cement plant producing 3000 tons of clinker per day. This analysis used reference values from Secil an international company for cement and building materials to determine the required scale of the oxygen and hydrogen production respectively and calculate the CAPEX of each approach. It is concluded that oxygen enrichment can provide substantial fuel savings for a relatively low cost despite a possible significant increase in NOx emissions. However hydrogen production at this scale is not currently economically viable.

As the global energy transition progresses a range of drivers and barriers will continue to shape consumer attitudes and behavioural intentions towards emerging low-carbon technologies. The innovation-decision process for technologies composing the residential sector such as hydrogen-fuelled heating and cooking appliances is inherently governed by the complex interplay between perceptual cognitive and emotional factors. In response this study responds to the call for an integrated research perspective to advance theoretical and empirical insights on consumer engagement in the domestic hydrogen transition. Drawing on online survey data collected in the United Kingdom where a policy decision on ‘hydrogen homes’ is set for 2026 this study systematically explores whether an integrated modelling approach supports higher levels of explanatory and predictive power. Leveraging the foundations of the unified theory of domestic hydrogen acceptance the analysis suggests that production perceptions public trust perceived relative advantage safety perceptions knowledge and awareness and positive emotions will shape consumer support for hydrogen homes. Conversely perceived disruptive impacts perceived socio-economic costs financial perceptions and negative emotions may impede the domestic hydrogen transition. Consumer acceptance stands to significantly shape deployment prospects for hydrogen boilers and hobs which are perceived to be somewhat advantageous to natural gas appliances from a technological and safety perspective. The study attests to the predictive benefits of adopting an integrated theoretical perspective when modelling the early stages of the innovation-decision process while acknowledging opportunities for leveraging innovative research approaches in the future. As national hydrogen economies gain traction adopting a neuroscience-based approach may help deepen scientific understanding regarding the neural psychological and emotional signatures shaping consumer perspectives towards hydrogen homes.

Natural gas (NG) is favored for transportation due to its availability and lower CO2 emissions than fossil fuels despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies using hydrogen (H2 ) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions making it a promising option for diesel engines. Due to the importance and novelty of this the continuation of ongoing research and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design operating conditions fuel mixing ratios and supplying techniques on the CO CO2 NOx and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NOx and CO2 compared to pure diesel. However using hydrogen with diesel reduces CO CO2 and HC emissions but increases NOx. On the other hand HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately resulting in decreased emissions of CO CO2 HC and NOx. The inclusion of hydrogen improves combustion efficiency reduces ignition delay and enhances heat release and in-cylinder pressure. Additionally operational parameters such as engine power speed load air–fuel ratio compression ratio and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels.

Due to the aviation energy sector's increasing contribution to climate change and the impact of climate change on the aviation sector determining key energy policy and economic research priorities for enabling an effective and equitable aviation climate action is becoming an increasingly important topic. In this perspective we address this research need using a four-pronged methodology. It includes (i) identifying topical matters highlighted in the media (news); (ii) formulating novel and feasible policy and economic research challenges that pertain to these contemporary issues; (iii) cross-referencing the proposed research challenges with academic literature to confirm their novelty and refining them as necessary; and (iv) validating the importance novelty and feasibility of these research challenges through consultation with a diverse group of aviation experts in fuel policy technology and infrastructure fields. Our results highlight twelve main themes. Among these the top emerging policy and economic research challenges as prioritized by expert input are – (i) frameworks for equitable responsibility allocation between developed and developing country airlines for future emissions; (ii) cost analysis of airlines' net-zero by 2050 commitments; (iii) effectiveness and opportunity cost of airlines investing in offsetting relative to reduction measures; (iv) EU aviation policies' historical and potential effects on airfares demand emissions EU air carriers' competitiveness passenger traffic through EU hubs regional economies and social climate funds' ability to mitigate distributional effects of EU aviation policies. These identified priorities can steer both industry and academic research toward creating practical recommendations for policymakers and industry participants. When it comes to future research the ever-changing nature of the challenges in achieving aviation climate action means that our findings might need regular updates.

We present an optimization model of an energy district in South Italy that supplies baseload electricity and hydrogen services. The district is sized such that a nuclear reactor could provide these services. We define scenarios for 2050 to explore the system effects of discount rate sensitivity vetoes on technologies and cost uncertainties. We address the following issues relevant to decarbonization in South Italy: land-based wind and solar vs. exclusive solar rooftop extra cost of a veto on nuclear conservative assumptions on future storage technology and the role of pumped hydro storage lack of low-cost geological storage of hydrogen and the industrial competitiveness of this carrier and the methanation synergy with the agroforestry sector. Our results quantify the high system cost of vetoes on land-based wind and solar. Nuclear may enter the optimal mix only with a veto against onshore wind and a hypothesis of equal project risk hence an equal discount rate with renewables. Scenarios with land-based wind and solar obtain low-cost hydrogen and thus allow industrial uses for this carrier. The methanation synergy with the agroforestry sector does not offer a system cost advantage but improves the district’s configuration. The extra cost of full decarbonization relative to unregulated fossil gas is small with land-based wind and solar and significant with vetoes to these technologies.

The impacts of climate change are real and in many parts of the world testify to its harsh reality including rampant extreme weather events droughts heat wildfires and flooding which have recorded in places which have not experienced them in recent memory. In the quest to avert such events there is a growing awareness and demand for sustainable processes and operations. Today sustainability encompasses a balance between ecological footprint and human development index taking into consideration economics the green environment safety quality ethics diversity and inclusion (D&I) and communities. This article presents some steps that have been taken by Algeria to balance energetic autonomy and sustainable development and a case study on green hydrogen production employing membrane processes. Algeria’s objective to join the global fight against climate change is to develop its green hydrogen base. Given its resources including available solar and wind power seawater desalination plants building capacity and its favorable location it is developing its green hydrogen economy to supply hydrogen especially to Europe. This presents an opportunity for other developing nations especially in Africa to gain from this experience.

This study explores the potentiality of low/zero carbon fuels such as methanol methane and hydrogen for motor applications to pursue the goal of energy security and environmental sustainability. An experimental investigation was performed on a spark ignition engine equipped with both a port fuel and a direct injection system. Liquid fuels were injected into the intake manifold to benefit from a homogeneous charge formation. Gaseous fuels were injected in direct mode to enhance the efficiency and prevent abnormal combustion. Tests were realized at a fixed indicated mean effective pressure and at three different engine speeds. The experimental results highlighted the reduction of CO and CO2 emissions for the alternative fuels to an extent depending on their properties. Methanol exhibited high THC and low NOx emissions compared to gasoline. Methane and even more so hydrogen allowed for a reduction in THC emissions. With regard to the impact of gaseous fuels on the NOx emissions this was strongly related to the operating conditions. A surprising result concerns the particle emissions that were affected not only by the fuel characteristics and the engine test point but also by the lubricating oil. The oil contribution was particularly evident for hydrogen fuel which showed high particle emissions although they did not contain carbon atoms.

This study aimed to compare hydrogen ammonia methanol and waste-derived biofuels as shipping fuels using life cycle assessment to establish what potential they have to contribute to the shipping industry’s 100% greenhouse gas emission reduction target. A novel approach was taken where the greenhouse gas emissions associated with one year of global shipping fleet operations was used as a common unit for comparison therefore allowing the potential life cycle greenhouse gas emission reduction from each fuel option to be compared relative to Paris Agreement compliant targets for international shipping. The analysis uses life cycle assessment from resource extraction to use within ships with all GHGs evaluated for a 100-year time horizon (GWP100). Green hydrogen waste-derived biodiesel and bio-methanol are found to have the best decarbonisation po tential with potential emission reductions of 74–81% 87% and 85–94% compared to heavy fuel oil; however some barriers to shipping’s decarbonisation progress are identified. None of the alternative fuels considered are currently produced at a large enough scale to meet shipping’s current energy demand and uptake of alternative fuel vessels is too slow considering the scale of the challenge at hand. The decarbonisation potential from alternative fuels alone is also found to be insufficient as no fuel option can offer the 100% emission reduction required by the sector by 2050. The study also uncovers several sensitives within the life cycles of the fuel options analysed that have received limited attention in previous life cycle investigations into alternative shipping fuels. First the choice of allocation method can potentially double the life cycle greenhouse gas emissions of e-methanol due to the carbon ac counting challenges of using waste carbon dioxide streams during fuel production. This leads to concerns related to the true impact of using carbon dioxide captured from fossil-fuelled processes to produce a combustible product due to the resultant high downstream emissions. Second nitrous oxide emissions from ammonia combustion are found to be highly sensitive due to high greenhouse gas potency potentially offsetting any greenhouse reduction potential compared to heavy fuel oil. Further uncertainties are highlighted due to limited available data on the rate of nitrous oxide production from ammonia engines. The study therefore highlights an urgent need for the shipping sector to consider these factors when investing in new ammonia and methanol engines; failing to do so risks jeopardizing the sector’s progress towards decarbonisation. Finally whilst alternative fuels can offer good decarbonisation potential (particularly waste derived biomethanol and bio-diesel and green hydrogen) this cannot be achieved without accelerated investment in new and retrofit vessels and new fuel supply chains: the research concludes that existing pipeline of vessel orders and fuel production facilities is insufficient. Furthermore there is a need to integrate alternative fuel uptake with other decarbonisation strategies such as slow steaming and wind propulsion.

Hydrogen and methane as secondary fuels in diesel engines can be promising solutions to meet energy demand. The current study investigated the effect of the specialty gases of different compositions on diesel engine performance and exhaust gases. Four gases with various compositions of exhaust gas recirculation (Carbon monoxide Carbon dioxide and Nitrogen) and fuels (Hydrogen and Methane) were used at various mass flow rates of 10 20 and 25 LPM (liter per minute) and various engine speeds of 2000 2500 3000 and 3500 rpm (revolutions per minute). The procured results revealed that adding specialty gases improved brake thermal efficiency and power. Similarly the brake-specific fuel consumption was also massively retarded compared to diesel due to the influence of the hydrogen and methane composition. However the fuel with the higher nitrogen reported less BTE (brake thermal efficiency) and comparatively higher exhaust gas temperature owing to the higher presence of nitrogen in their composition. Regarding emissions including exhaust gas recirculation dropped the formation of pollutants efficiently compared to diesel. Among various fuels Case 1 (30 % H2 5 % CH4 5 CO2 and 60 % CO) reported the lowest emission of NOx and Case 2 (25 % H2 5 % CH4 5 CO2 30 % CO and 35 % N2) of CO and CO2 emissions. Generally specialty gases with a variable composition of exhaust gas recirculation gases can be a promising sustainable replacement for existing fossil fuels.

Intra-day control and scheduling of energy systems require high-speed computation and strong robustness. Conventional mathematical driven approaches usually require high computation resources and have difficulty handling system uncertainties. This paper proposes two data-driven scheduling approaches for hydrogen penetrated energy system (HPES) operational scheduling. The two data-driven approaches learn the historical optimization results calculated out using the mixed integer linear programing (MILP) and conditional value at risk (CVaR) respectively. The intra-day rolling optimization mechanism is introduced to evaluate the proposed data-driven scheduling approaches MILP data-driven approach and CVaR data-driven approach along with the forecasted renewable generation and load demands. Results show that the two data-driven approaches have lower intra-day operational costs compared with the MILP based method by 1.17% and 0.93%. In addition the combined cooling and heating plant (CCHP) has a lower frequency of changing the operational states and power output when using the MILP data-driven approach compared with the mathematical driven approaches.

To meet environmental goals while maintaining economic competitiveness worldwide ports have increased the amount of renewable energy production and have focused in optimizing performances and energy efficiency. However carbon-neutral operation of industrial port areas (IPA) is challenging and requires the decarbonization of industrial processes and heavy transport systems. This study proposes a comprehensive review of decarbon ization strategies for IPA with a particular focus on the role that green hydrogen could play when used as renewable energy carrier. Much information on existing and future technologies was also derived from the analysis of 74 projects (existing and planned) in 36 IPAs 80 % of which are in Europe concerning hydrogenbased decarbonization strategies. The overall review shows that engine operation of ships at berth are respon sible of more than 70 % of emissions in ports. Therefore onshore power supply (OPS) seems to be one of the main strategies to reduce port pollution. Nevertheless OPS powered by hydrogen is not today easily achievable. By overcoming the current cost-related and regulation barriers hydrogen can also be used for the import/export of green energy and the decarbonization of hard-to-abate sectors. The technical and economic data regarding hydrogen-based technologies and strategies highlighted in this paper are useful for further research in the field of definition and development of decarbonization strategies in the IPA.

Renewable Energy Sources (RESs) are characterized by high unevenness cyclicality and seasonality of energy production. Due to the trends in the production of electricity itself and the utilization of hydrogen distributed generation systems are preferred. They can be connected to the energy distribution network or operate without its participation (off-grid). However in both cases such distributed energy sources should be balanced in terms of power generation. According to the authors it is worth combining different RESs to ensure the stability of energy production from such a mix. Within the mix the sources can complement and replace each other. According to the authors an effective system for generating energy from RESs should contain at least two different sources and energy storage. The purpose of the analyses and calculations performed is to determine the characteristics of energy generation from a photovoltaic system and a wind turbine with a specific power and geographical location in the Lublin region in Poland. Another important goal is to determine the substitutability of the sources studied. Probabilistic analysis will be used to determine the share of given energy sources in the energy mix and will allow us to estimate the size of the stationary energy storage. The objective of these procedures is to strive for the highest possible share of renewable energy in the total energy required to charge electric vehicle fleets and to produce low-emission hydrogen for transportation. The article proves that the appropriately selected components of the photovoltaic and wind energy mix located in the right place lead to the self-balancing of the local energy network using a small energy storage. The conclusions drawn from the conducted research can be used by RES developers who intend to invest in new sources of power generation to produce low-emission hydrogen. This is in line with the current policy of the European Union aimed at climate and energy transformation of many companies using green hydrogen.

Alkaline water electrolysis is a key technology for large-scale hydrogen production. In this process safety and efficiency are among the most essential requirements. Hence optimization strategies must consider both aspects. While experimental optimization studies are the most accurate solution model-based approaches are more cost and time-efficient. However validated process models are needed which consider all important influences and effects of complete alkaline water electrolysis systems. This study presents a dynamic process model for a pressurized alkaline water electrolyzer consisting of four submodels to describe the system behavior regarding gas contamination electrolyte concentration cell potential and temperature. Experimental data from a lab-scale alkaline water electrolysis system was used to validate the model which could then be used to analyze and optimize pressurized alkaline water electrolysis. While steady-state and dynamic solutions were analyzed for typical operating conditions to determine the influence of the process variables a dynamic optimization study was carried out to optimize an electrolyte flow mode switching pattern. Moreover the simulation results could help to understand the impact of each process variable and to develop intelligent concepts for process optimization

Green hydrogen is considered the most suitable choice for the future energy market both as energy storage media energy vector and fuel for transportation industry and other applications. In the last twenty years increasing efforts have been dedicated to green hydrogen technologies development but still today a number of issues are claimed in justifying the delay in its large scale application and the star vation of its market. Moreover some new questions seem ready to be put on the table for justifying the delay in green hydrogen technologies applications. In this paper a critical analysis of recent literature and institutional reports is carried out with the aim of understanding what is the real state of the play. In particular peculiar advantages and shortcomings of different green hydrogen technologies (biomass pyrolysis and gasification water electrolysis etc.) have been analysed and compared with a focus on the electrolysis process as the most promising method for large scale and distributed generation of hydrogen. Some geopolitical and economic aspects associated with the transition to a green hydrogen economy - including the feared exacerbation of the water crisis - have been widely examined and discussed with the purpose of identifying approaches and solutions to accelerate the mentioned transition.