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Optimization of High-Temperature Electrolysis System for Hydrogen Production Considering High-Temperature Degradation
Mar 2023
Publication
Solid oxide electrolysis cells (SOECs) have great application prospects because of their excellent performance but the long-term applications of the stacks are restricted by the structural degradation under the high-temperature conditions. Therefore an SOEC degradation model is developed and embedded in a process model of the high-temperature steam electrolysis (HTSE) system to investigate the influence of the stack degradation at the system level. The sensitivity analysis and optimization were carried out to study the influence factors of the stack degradation and system hydrogen production efficiency and search for the optimal operating conditions to improve the hydrogen production efficiency and mitigate the stack degradation. The analysis results show that the high temperature and large current density can accelerate the stack degradation but improve the hydrogen production efficiency while the high temperature gradually becomes unfavorable in the late stage. The low air-to-fuel feed ratio is beneficial to both the degradation rate and hydrogen production efficiency. The results show that the optimization method can improve the hydrogen production efficiency and inhibit the stack degradation effectively. Moreover part of the hydrogen production efficiency has to be sacrificed in order to obtain a lower stack degradation rate.
Hydrogenization of Underground Storage of Natural Gas
Aug 2015
Publication
The intermittent production of the renewable energy imposes the necessity to temporarily store it. Large amounts of exceeding electricity can be stored in geological strata in the form of hydrogen. The conversion of hydrogen to electricity and vice versa can be performed in electrolyzers and fuel elements by chemical methods. The nowadays technical solution accepted by the European industry consists of injecting small concentrations of hydrogen in the existing storages of natural gas. The progressive development of this technology will finally lead to the creation of underground storages of pure hydrogen. Due to the low viscosity and low density of hydrogen it is expected that the problem of an unstable displacement including viscous fingering and gravity overriding will be more pronounced. Additionally the injection of hydrogen in geological strata could encounter chemical reactivity induced by various species of microorganisms that consume hydrogen for their metabolism. One of the products of such reactions is methane produced from Sabatier reaction between H2 and CO2. Other hydrogenotrophic reactions could be caused by acetogenic archaea sulfate-reducing bacteria and iron-reducing bacteria. In the present paper a mathematical model is presented which is capable to reflect the coupled hydrodynamic and bio-chemical processes in UHS. The model has been numerically implemented by using the open source code DuMuX developed by the University of Stuttgart. The obtained bio-chemical version of DuMuX was used to model the evolution of a hypothetical underground storage of hydrogen. We have revealed that the behavior of an underground hydrogen storage is different than that of a natural gas storage. Both the hydrodynamic and the bio-chemical effects contribute to the different characteristics.
Biological CO2-Methanation: An Approach to Standardization
May 2019
Publication
Power-to-Methane as one part of Power-to-Gas has been recognized globally as one of the key elements for the transition towards a sustainable energy system. While plants that produce methane catalytically have been in operation for a long time biological methanation has just reached industrial pilot scale and near-term commercial application. The growing importance of the biological method is reflected by an increasing number of scientific articles describing novel approaches to improve this technology. However these studies are difficult to compare because they lack a coherent nomenclature. In this article we present a comprehensive set of parameters allowing the characterization and comparison of various biological methanation processes. To identify relevant parameters needed for a proper description of this technology we summarized existing literature and defined system boundaries for Power-to-Methane process steps. On this basis we derive system parameters providing information on the methanation system its performance the biology and cost aspects. As a result three different standards are provided as a blueprint matrix for use in academia and industry applicable to both biological and catalytic methanation. Hence this review attempts to set the standards for a comprehensive description of biological and chemical methanation processes.
Decarbonizing the Spanish Transportation Sector by 2050: Design and Techno-economic Assessment of the Hydrogen Generation and Supply Chain
May 2023
Publication
The transport sector is difficult to decarbonize due to its high reliance on fossil fuels accounting for 37% of global end-use sectors emissions in 2021. Therefore this work proposes an energy model to replace the Spanish vehicle fleet by hydrogen-fueled vehicles by 2050. Thus six regions are defined according to their proximity to regasification plants where hydrogen generation hubs are implemented. Likewise renewables deployment is subject to their land availability. Hydrogen is transported through an overhauled primary natural gas transport network while two distribution methods are compared for levelized cost of hydrogen minimization: gaseous pipeline vs liquid hydrogen supply in trucks. Hence a capacity of 443.1 GW of renewables 214 GW of electrolyzers and 3.45 TWh of hydrogen storage is required nationwide. Additionally gaseous hydrogen distribution is on average 17% cheaper than liquid hydrogen delivery. Finally all the regions present lower prices per km traveled than gasoline or diesel.
An Overview on Safety Issues Related to Hydrogen and Methane Blend Applications in Domestic and Industrial Use
Sep 2017
Publication
The share of electrical energy hailing from renewable sources in the European electricity mix is increasing. The match between renewable power supply and demand has become the greatest challenge to cope with. Gas infrastructure can accommodate large volumes of electricity converted into gas whenever this supply of renewable power is larger than the grid capacity or than the electricity demand. The Power-to-Gas (P2G) process chain could play a significant role in the future energy system. Renewable electric energy can be transformed into storable hydrogen via electrolysis and subsequent methanation. The aim of this paper is to provide an overview of the required technical adaptations of the most common devices for end users such as heating plants CHP systems home gas furnaces and cooking surfaces wherever these are fuelled with methane and hydrogen blends in variable percentages by volume. Special attention will be given to issues related to essential safety standards firstly comparing existing Italian and European regulations in this regard and secondly highlighting the potential need for legislation to regulate the suitability of hydrogen methane blends. Finally a list of foreseeable technical solutions will be provided and discussed thoroughly
The Effect of Explosions on the Protective Wall of a Containerized Hydrogen Fuel Cell System
Jun 2023
Publication
With the development of hydrogen energy containerized hydrogen fuel cell systems are being used in distributed energy-supply systems. Hydrogen pipelines and electronic equipment of fuel cell containers can trigger hydrogen-explosion accidents. In the present study Computational Fluid Dynamics (CFD) software was used to calculate the affected areas of hydrogen fuel cell container-explosion accidents with and without protective walls. The protective effects were studied for protective walls at various distances and heights. The results show that strategically placing protective walls can effectively block the propagation of shock waves and flames. However the protective wall has a limited effect on the reduction of overpressure and temperature behind the wall when the protective wall is insufficiently high. Reflected explosion shock waves and flames will cause damage to the area inside the wall when the protective wall is too close to the container. In this study a protective wall that is 5 m away from the container and 3 m high can effectively protect the area behind the wall and prevent damage to the container due to the reflection of shock waves and flame. This paper presents a suitable protective wall setting scheme for hydrogen fuel cell containers.
Evaluation of Hydrogen Transportation Networks - A Case Study on the German Energy System
May 2023
Publication
Not only due to the energy crisis European policymakers are exploring options to substitute natural gas with renewable hydrogen. A condition for the application of hydrogen is a functioning transportation infrastructure. However the most efficient transport of large hydrogen quantities is still unclear and deeper analyses are missing. A promising option is converting the existing gas infrastructure. This study presents a novel approach to develop hydrogen networks by applying the Steiner tree algorithm to derive candidates and evaluate their costs. This method uses the existing grid (brownfield) and is compared to a newly built grid (Greenfield). The goal is the technical and economic evaluation and comparison of hydrogen network candidates. The methodology is applied to the German gas grid and demand and supply scenarios covering the industry heavy-duty transport power and heating sector imports and domestic production. Five brownfield candidates are compared to a greenfield candidate. The candidates differ by network length and pipeline diameters to consider the transported volume of hydrogen. The economic evaluation concludes that most brownfield candidates’ cost is significantly lower than those of the greenfield candidate. The candidates can serve as starting points for flow simulations and policymakers can estimate the cost based on the results.
Challenges Toward Achieving a Successful Hydrogen Economy in the US: Potential End-use and Infrastructure Analysis to the Year 2100
Jul 2022
Publication
Fossil fuels continue to exacerbate climate change due to large carbon emissions resulting from their use across a number of sectors. An energy transition away from fossil fuels seems inevitable and energy sources such as renewables and hydrogen may provide a low carbon alternative for the future energy system particularly in large emitting nations such as the United States. This research quantifies and maps potential hydrogen fuel distribution pathways for the continental US reflecting technological changes barriers to deployment and end-use-cases from 2020 to 2100 clarifying the potential role of hydrogen in the US energy transition. The methodology consists of two parts a linear optimization of the global energy system constrained by carbon reduction targets and system cost followed by a projection of hydrogen infrastructure development. Key findings include the emergence of trade pattern diversification with a greater variety of end-uses associated with imported fuels and greater annual hydrogen consumption over time. Further sensitivity analysis identified the influence of complementary technologies including nuclear power and carbon capture and storage technologies. We conclude that hydrogen penetration into the US energy system is economically viable and can contribute toward achieving Paris Agreement and more aggressive carbon reduction targets in the future.
Cost and Thermodynamic Analysis of Wind-Hydrogen Production via Multi-energy Systems
Mar 2024
Publication
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.
Fueling Tomorrow's Commute: Current Status and Prospects of Public Bus Transit Fleets Powered by Sustainable Hydrogen
Apr 2024
Publication
Transportation is an economic sector that contributes significantly to global warming due to its high consumption of fossil fuels and sustainably produced hydrogen is a major contender for an alternative clean energy source. Public transit is vital for environmental sustainability via reducing individual vehicle usage and traffic congestion and the prospect of powering buses using hydrogen fuel has been extensively studied lately. This paper seeks to comprehensively review the current status of research on hydrogen-powered buses considering triple bottom line sustainability perspectives. A brief technical overview of prospective environmentally benign hydrogen production processes has been presented. Technological economic and environmental findings and research trends seen in recent analyses on hydrogen-powered buses have been summarized along with the status quo of global hydrogen refuelling stations. Identified focal points for future studies include performance enhancements refuelling infrastructure propagation and policy formulation. The conclusions derived from this review will benefit the accelerated deployment of hydrogen-fuelled public transit fleets.
Concept Design and Energy Balance Optimization of a Hydrogen Fuel Cell Helicoptor for Unmanned Aerial Vehicle and Aerotaxi Applications
May 2023
Publication
In the new scenario where the transportation sector must be decarbonized to limit global warming fuel cellpowered aerial vehicles have been selected as a strategic target application to compose part of the urban fleet to minimize road transport congestion and make goods and personal transportation fast and efficient. To address the necessity of clean and efficient urban air transport this work consists of the conceptual development of a lightweight rotary-winged transport vehicle using a hydrogen-based fuel cell propulsion system and the optimization of its energy balance. For that purpose the methods for integrating the coupled aerodynamic and propulsion system sizing and optimization was developed with the aim of designing concepts capable of carrying 0 (unmanned aerial vehicle — Design 1) and 1 (Aerotaxi — Design 2) passengers for a distance of 300 km at a cruise altitude of 500 m with a minimum climbing rate capability of 6 m s−1 at 1000 m. The results show how these designs with the desired performance specifications can be obtained with a vehicle mass ranging from 416 to 648 kg depending on the application and with specific range and endurance respectively within 46.2–47.8 km/kg and 20.4–21.3 min/kg for design 1 and 33.3–33.8 km/kg and 12.5–13.9 min/kg for design 2.
Risk Management of Energy Communities with Hydrogen Production and Storage Technologies
Jul 2023
Publication
The distributed integration of renewable energy sources plays a central role in the decarbonization of economies. In this regard energy communities arise as a promising entity to coordinate groups of proactive consumers (prosumers) and incentivize investment on clean technologies. However the uncertain nature of renewable energy generation residential loads and trading tariffs pose important challenges both at the operational and economic levels. We study how this management can be directly undertaken by an arbitrageur that making use of an adequate price-based demand response (real-time pricing) system serves as an intermediary with the central electricity market to coordinate different types of prosumers under risk aversion. In particular we consider a sequential futures and spot market where the aggregated shortage or excess of energy within the community can be traded. We aim to study the impact of new hydrogen production and storage technologies on community operation and risk management. These interactions are modeled as a game theoretical setting in the form of a stochastic two-stage bilevel optimization problem which is later reformulated without approximation as a single-level mixed-integer linear problem (MILP). An extensive set of numerical experiments based on real data is performed to study the operation of the energy community under different technical and economical conditions. Results indicate that the optimal involvement in futures and spot markets is highly conditioned by the community’s risk aversion and self-sufficiency levels. Moreover the external hydrogen market has a direct effect on the community’s internal price-tariff system and depending on the market conditions may worsen the utility of individual prosumers.
Decarbonisation of Heavy-duty Diesel Engines Using Hydrogen Fuel: A Review of the Potential Impact NOx Emissions
Jul 2022
Publication
As countries seek ways to meet climate change commitments hydrogen fuel offers a low-carbon alternative for sectors where battery electrification may not be viable. Blending hydrogen with fossil fuels requires only modest technological adaptation however since combustion is retained nitrogen oxides (NOx) emissions remain a potential disbenefit. We review the potential air quality impacts arising from the use of hydrogen–diesel blends in heavy-duty diesel engines a powertrain which lends itself to hydrogen co-fuelling. Engine load is identified as a key factor influencing NOx emissions from hydrogen–diesel combustion in heavy-duty engines although variation in other experimental parameters across studies complicates this relationship. Combining results from peer-reviewed literature allows an estimation to be made of plausible NOx emissions from hydrogen–diesel combustion relative to pure-diesel combustion. At 0–30% engine load which encompasses the average load for mobile engine applications NOx emissions changes were in the range 59 to +24% for a fuel blend with 40 e% hydrogen. However at 50–100% load which approximately corresponds to stationary engine applications NOx emissions changes were in the range 28 to +107%. Exhaust gas recirculation may be able to reduce NOx emissions at very high and very low loads when hydrogen is blended with diesel and existing exhaust aftertreatment technologies are also likely to be effective. Recent commercial reporting on the development of hydrogen and hydrogen–diesel dual fuel combustion in large diesel engines are also summarised. There is currently some disconnection between manufacturer reported impacts of hydrogen-fuelling on NOx emissions (always lower emissions) and the conclusions drawn from the peer reviewed literature (frequently higher emissions).
Performance of Three Typical Domestic Gas Stoves Operated with Methane-hydrogen Mixture
Dec 2022
Publication
Hydrogen blending into natural gas has attracted significant attention in domestic applications. The paper studied the effects of natural gas mixed with hydrogen at 0% (vol) 5% 10% 15% 20% and 25% on the performance of typical round-port gas stove (TRPGS) swirling strip-port gas stove (SSPGS) and radiant porous media gas stove (RPMGS). The experimental results show that flame length shortens with the increase of hydrogen proportion and the combustion remains stable when the hydrogen proportion is equal to or less than 25%. With increasing hydrogen proportion the measured heat inputs of the three types of domestic gas stoves decrease gradually and the average thermal efficiency of TRPGS and SSPGS increase by 0.82% and 1.18% respectively. In addition the average efficiency of the RPMGS first increases by 1.35% under a hydrogen proportion of 15% and then decreases by 1.36% under a hydrogen proportion of 25%. In terms of flue gas emission CO emission reduces significantly with increasing hydrogen proportion while NOX emissions remain almost unchanged.
Research Progress of Hydrogen Production Technology and Related Catalysts by Electrolysis of Water
Jun 2023
Publication
As a clean and renewable energy source for sustainable development hydrogen energy has gained a lot of attention from the general public and researchers. Hydrogen production by electrolysis of water is the most important approach to producing hydrogen and it is also the main way to realize carbon neutrality. In this paper the main technologies of hydrogen production by electrolysis of water are discussed in detail; their characteristics advantages and disadvantages are analyzed; and the selection criteria and design criteria of catalysts are presented. The catalysts used in various hydrogen production technologies and their characteristics are emphatically expounded aiming at optimizing the existing catalyst system and developing new high-performance high-stability and low-cost catalysts. Finally the problems and solutions in the practical design of catalysts are discussed and explored.
Evaluation of Surplus Hydroelectricity Potential in Nepal until 2040 and its Use for Hydrogen Production Via Electrolysis
May 2023
Publication
The abundant hydro resources in Nepal have resulted in the generation of electricity almost exclusively from hydropower plants. Several hydropower plants are also currently under construction. There is no doubt that the surplus electricity will be significantly high in the coming years. Given the previous trend in electricity consumption it will be a challenge to maximize the use of surplus electricity. In this work the potential solutions to maximize the use of this surplus electricity have been analysed. Three approached are proposed: (i) increasing domestic electricity consumption by shifting the other energy use sectors to electricity (ii) cross-border export of electricity and (iii) conversion of electricity to hydrogen via electrolysis. The current state of energy demand and supply patterns in the country are presented. Future monthly demand forecasts and surplus electricity projections have been made. The hydrogen that can be produced with the surplus electricity via electrolysis is determined and an economic assessment is carried out for the produced hydrogen. The analysis of levelized cost of hydrogen (LCOH) under different scenarios resulted values ranging from 3.8 €/kg to 4.5 €/kg.
Techno-economic Analysis of Large-scale Green Hydrogen Production and Storage
Jun 2023
Publication
Producing clean energy and minimising energy waste are essential to achieve the United Nations sustainable development goals such as Sustainable Development Goal 7 and 13. This research analyses the techno-economic potential of waste heat recovery from multi-MW scale green hydrogen production. A 10 MW proton exchange membrane electrolysis process is modelled with a heat recovery system coupled with an organic Rankine cycle (ORC) to drive the mechanical compression of hydrogen. The technical results demonstrate that when implementing waste heat recovery coupled with an ORC the first-law efficiency of electrolyser increases from 71.4% to 98%. The ORC can generate sufficient power to drive the hydrogen's compression from the outlet pressure at the electrolyser 30 bar up to 200 bar. An economic analysis is conducted to calculate the levelised cost of hydrogen (LCOH) of system and assess the feasibility of implementing waste heat recovery coupled with ORC. The results reveal that electricity prices dominate the LCOH. When electricity prices are low (e.g. dedicated offshore wind electricity) the LCOH is higher when implementing heat recovery. The additional capital expenditure and operating expenditure associated with the ORC increases the LCOH and these additional costs outweigh the savings generated by not purchasing electricity for compression. On the other hand heat recovery and ORC become attractive and feasible when grid electricity prices are higher.
Just Trade-offs in a Net-zero Transition and Social Impact Assessment
Apr 2024
Publication
Countries around the world are prioritising net zero emissions to meet their Paris Agreement goals. The demand for social impact assessment (SIA) is likely to grow as this transition will require investments in decarbonisation projects with speed and at scale. There will be winners and losers of these projects because not everyone benefits the same; and hence trade-offs are inevitable. SIAs therefore should focus on understanding how the risks and benefits will be distributed among and within stakeholders and sectors and enable the identification of trade-offs that are just and fair. In this study we used a hypothetical case of large-scale hydrogen production in regional Australia and engaged with multi-disciplinary experts to identify justice issues in transitioning to such an industry. Using Rawlsian theory of justice as fairness we identified several tensions between different groups (national regional local inter and intra-communities) and sectors (environmental and economic) concerning the establishment of a hydrogen industry. These stakeholders and sectors will be disproportionately affected by this establishment. We argue that Rawlsian principles of justice would enable the practice of SIA to identify justice trade-offs. Further we conceptualise that a systems approach will be critical to facilitate a wider participation and an agile process for achieving just trade-offs in SIA.
How to Reduce the Greenhouse Gas Emissions and Air Pollution Caused by Light and Heavy Duty Vehicles with Battery-electric, Fuel Cell-electric and Catenary Trucks
Mar 2021
Publication
The reduction of greenhouse gas emissions is one of the greatest global challenges through 2050. Besides greenhouse gas emissions air pollution such as nitrogen oxide and particulate matter emissions has gained increasing attention in agglomerated areas with transport vehicles being one of the main sources thereof. Alternative fuels that fulfill the greenhouse gas reduction goals also offer the possibility of solving the challenge of rising urban pollution. This work focuses on the electric drive option for heavy and light duty vehicle freight transport. In this study fuel cell-electric vehicles battery-electric vehicles and overhead catenary line trucks were investigated taking a closer look at their potential to reduce greenhouse gas emissions and air pollution and also considering the investment and operating costs of the required infrastructure. This work was conducted using a bottom-up transport model for the federal state of North Rhine-Westphalia in Germany. Two scenarios for reducing these emissions were analyzed at a spatial level. In the first of these selected federal highways with the highest traffic volume were equipped with overhead catenary lines for the operation of diesel-hybrid overhead trucks on them. For the second spatial scenario the representative urban area of the city of Cologne was investigated in terms of air pollution shifting articulated trucks to diesel-hybrid overhead trucks and rigid trucks trailer trucks and light duty vehicles to battery-electric or fuel cell-electric drives. For the economic analysis the building up of a hydrogen infrastructure in the cases of articulated trucks and all heavy duty vehicles were also taken into account. The results showed that diesel-hybrid overhead trucks are only a cost-efficient solution for highways with high traffic volume whereas battery overhead trucks have a high uncertainty in terms of costs and technical feasibility. In general the broad range of costs for battery overhead trucks makes them competitive with fuel cell-electric trucks. Articulated trucks have the highest potential to be operated as overhead trucks. However the results indicated that air pollution is only partially reduced by switching conventional articulated trucks to electric drive models. The overall results show that a comprehensive approach such as fuel cell-electric drives for all trucks would most likely be more beneficial.
THyGA - Long Term Effect of H2 on Appliances Tested
May 2023
Publication
The goals of the long-term tests were to see the impact of blends of hydrogen and natural gas on the technical condition of the appliances and their performance after several hours of operation. To do so they were run through an accelerated test program amounting to more than 3000 testing hours for the boilers and more than 2500 testing hours for the cookers. The percentage of hydrogen in the test gas was 30% by volume. Three boilers and two cookers were tested by DGC and two boilers by GWI. This report describes the test protocol the results and analysis on the seven appliances tested.
Everything About Hydrogen Podcast: Hydrogen Review of 2022
Oct 2022
Publication
In order to wrap Season 3 of EAH appropriately we are honored to have our most popular EAH guest back with us Alicia Eastman President and Co-Founder of Intercontinental Energy is here to help us review the big hydrogen happenings of 2022 and preview some of the most important predictions and expectations for the sector coming for 2023.
The podcast can be found on their website.
The podcast can be found on their website.
Optimal Battery and Hydrogen Fuel Cell Sizing in Heavy-haul Locomotives
Jul 2023
Publication
Global supply chains must be decarbonised as part of meeting climate targets set by the United Nations and world leaders. Rail networks are vital infrastructure in passenger and freight transport however have not received the same push for decarbonisation as road transport. In this investigation we used real world data from locomotives operating on seven rail corridors to identify optimal battery capacity and hydrogen fuel cell (HFC) power in hybrid systems. We found that the required battery capacity is dependent on both the available regenerative braking energy and on the capacity required to buffer surpluses and deficits from the HFC. The optimal system for each corridor was identified however it was found that one 3.6 MWh battery and 860 kW HFC system could service six of the seven corridors. The optimal systems presented in this work suggest an average of around 5 h of battery storage for the HFC power which is larger than the 2 h previously reported in literature. This may indicate a gap between purely theoretical works that use only route topography and speed and those that employ real world locomotive data.
Strategies for Life Cycle Impact Reduction of Green Hydrogen Production - Influence of Electrolyser Value Chain Design
Mar 2024
Publication
Green Hydrogen (H2 via renewable-driven electrolysis) is emerging as a vector to meet net-zero emission targets provided it is produced with a low life cycle impact. While certification schemes for green H2 have been introduced they mainly focus on the embodied emissions from energy supply during electrolyser operation. This narrow focus on just operation is an oversight considering that a complete green H2 value chain also includes the electrolyser’s manufacturing transport/installation and end-of-life. Each step of this chain involves materials and energy flows that impart impacts that undermine the clean and sustainable status of H2. Therefore holistic and harmonised assessments of the green H2 production chain are required to ensure both economic and environmental deployment of H2. Herein we conduct an overarching environmental assessment encompassing the production chain described above using Australia as a case study. Our results indicate that while the energy source has the most impact material and manufacturing inputs associated with electrolyser production are increasingly significant as the scale of H2 output expands. Moreover wind power electrolysis has a greater chance of achieving green H2 certification compared to solar powered while increasing the amount of localised manufactured content and investment in end-of-life recycling of electrolyser components can reduce the overall life cycle impact of green H2 production by 20%.
Hydrogen Fuel Cell Integration and Testing in a Hybrid-electric Propulsion Rig
Jun 2023
Publication
On the road towards greener aviation hybrid-electric propulsion systems have emerged as a viable solution. In this paper a system based on hydrogen fuel cells is proposed and evaluated in a laboratory setting with its future integration in a propulsive system in mind and main focus on the ability to lessen the power demand on the opposing side of the bench. The setup consists in a parallel architecture with two power sources: a hydrogen fuel cell and a battery. First the performance of the fuel cell and its capability to provide power to one of the motors are analyzed. Then the entire parallel hybrid system is evaluated. Although the experimental setup was shown to be sub-optimal the results demonstrated the ability of this greener alternative to reduce power demand on the opposing side of the parallel configuration with a reduction of up to 40.3% in the highest load scenario and maximum power output on the fuel cell of 257.8 W. The stack performance was also concluded to be very dependent on the operating temperature.
A Theoretical Study on the Hydrogen Filling Process of the On-board Storage Cylinder in Hydrogen Refueling Station
May 2023
Publication
With the development of the hydrogen fuel automobile industry higher requirements are put forward for the construction of hydrogen energy infrastructure the matching of parameters and the control strategy of hydrogen filling rate in the hydrogen charging process of hydrogen refueling stations. At present the technological difficulty of hydrogen fueling is mainly reflected in the balanced treatment of reducing the temperature rise of hydrogen and shortening the filling time during the fast filling process. Vehicle hydrogen storage cylinder (VHSC) is one of the important components of hydrogen fuel cell vehicles. This study proposed a theoretical model for calculating the temperature rise in the VHSC during the high pressure refueling process and revealed the hydrogen temperature rise during refueling. A hydrogen temperature rise prediction model was constructed to elucidate the relationship between filling parameters and temperature rise. The filling process of VHSC was analyzed from the theoretical method. The theoretical analysis results were consistent with the simulation and experimental analysis results which provided a theoretical basis for the current hydrogen temperature control algorithm of the gas source in the hydrogen refueling station and then reduced the energy consumption required for hydrogen cooling in the hydrogen refueling station.
Life Cycle Cost Analysis of an Autonomous Underwater Vehicle that Employs Hydrogen Fuel Cell
Feb 2024
Publication
The use of autonomous vehicles for marine and submarine work has risen considerably in the last decade. Developing new monitoring systems navigation and communications technologies allows a wide range of operational possibilities. Autonomous Underwater Vehicles (AUVs) are being used in offshore missions and applications with some innovative purposes by using sustainable and green energy sources. This paper considers an AUV that uses a hydrogen fuel cell achieving zero emissions. This paper analyses the life cycle cost of the UAV and compares it with a UAV powered by conventional energy. The EN 60300-3-3 guidelines have been employed to develop the cost models. The output results show estimations for the net present value under different scenarios and financial strategies. The study has been completed with the discount rate sensibility analysis in terms of financial viability.
Potential Domestic Energy System Vulnerabilities from Major Exports of Green Hydrogen: A Case Study of Australia
Aug 2023
Publication
Australia has clear aspirations to become a major global exporter of hydrogen as a replacement for fossil fuels and as part of the drive to reduce CO2 emissions as set out in the National Hydrogen Strategy released in 2019 jointly by the federal and state governments. In 2021 the Australian Energy Market Operator specified a grid forecast scenario for the first time entitled “hydrogen superpower”. Not only does Australia hope to capitalise on the emerging demand for zero-carbon hydrogen in places like Japan and South Korea by establishing a new export industry but it also needs to mitigate the built-in carbon risk of its export revenue from coal and LNG as major customers such as Japan and South Korea move to decarbonise their energy systems. This places hydrogen at the nexus of energy climate change mitigation and economic growth with implications for energy security. Much of the published literature on this topic concentrates on the details of what being a major hydrogen exporter will look like and what steps will need to be taken to achieve it. However there appears to be a gap in the study of the implications for Australia’s domestic energy system in terms of energy security and export economic vulnerability. The objective of this paper is to develop a conceptual framework for the implications of becoming a major hydrogen exporter on Australia’s energy system. Various green hydrogen export scenarios for Australia were compared and the most recent and comprehensive was selected as the basis for further examination for domestic energy system impacts. In this scenario 248.5 GW of new renewable electricity generation capacity was estimated to be required by 2050 to produce the additional 867 TWh required for an electrolyser output of 2088 PJ of green hydrogen for export which will comprise 55.9% of Australia’s total electricity demand at that time. The characteristics of comparative export-oriented resources and their interactions with the domestic economy and energy system are then examined through the lens of the resource curse hypothesis and the LNG and aluminium industries. These existing resource export frameworks are reviewed for applicability of specific factors to export-oriented green hydrogen production with applicable factors then compiled into a novel conceptual framework for exporter domestic implications from large-scale exports of green hydrogen. The green hydrogen export superpower (2050) scenario is then quantitatively assessed using the established indicators for energy exporter vulnerability and domestic energy security comparing it to Australia’s 2019 energy exports profile. This assessment finds that in almost all factors exporter vulnerability is reduced and domestic energy security is enhanced by the transition from fossil fuel exports to green hydrogen with the exception of an increase in exposure of the domestic energy system to international market forces.
The UK Hydrogen Innovation Opportunity
Apr 2024
Publication
The report considers the full end-to-end nature of the hydrogen economy to ensure there is a common understanding of the economic opportunity it could represent by 2050. Insights from across industry have brought clarity to both market and technology requirements identifying four focus areas that represent the greatest potential benefit for the UK. It highlights the steps needed to build the UK industrial capability and capacity to position the UK as a market leader. The UK Hydrogen Innovation Opportunity has been developed with and for industry with the first phase of industrial engagement involving over 250 businesses and 12 sector bodies. A second phase of industrial engagement will expand to a broader set of consulted stakeholder groups concluding with a report entitled Hydrogen Innovation: The Case for Action in summer 2024. This will seek to validate the proposed focus areas provide more detailed scope definition the size of the opportunity and outline the steps required to secure them for the UK.
Industrial Boilers: Study to Develop Cost and Stock Assumptions for Options to Enable or Require Hydrogen-ready Industrial Boilers
Dec 2022
Publication
This study aims to help the Department for Business Energy and Industrial Strategy (BEIS) determine whether the government should intervene to enable or require hydrogen-ready industrial boiler equipment. It will do this based on information from existing literature along with qualitative and quantitative information from stakeholder engagement. The study draws on evidence gathered through BEIS’ Call for Evidence (CfE) on hydrogen-ready industrial boilers. The assessment will advance the overall understanding of hydrogen-ready industrial boilers based on four outputs: definitions of hydrogen-readiness comparisons of the cost and resource requirement to install and convert hydrogen-ready industrial boiler equipment supply chain capacity for conversion to hydrogen and estimates of the UK industrial boiler population.
The Prospects of Hydrogen in Achieving Net Zero Emissions by 2050: A Critical Review
May 2023
Publication
Hydrogen (H2) usage was 90 metric tonnes (Mt) in 2020 almost entirely for industrial and refining uses and generated almost completely from fossil fuels leading to nearly 900 Mt of carbon dioxide emissions. However there has been significant growth of H2 in recent years. Electrolysers' total capacity which are required to generate H2 from electricity has multiplied in the past years reaching more than 300 MW through 2021. Approximately 350 projects reportedly under construction could push total capacity to 54 GW by the year 2030. Some other 40 projects totalling output of more than 35 GW are in the planning phase. If each of these projects is completed global H2 production from electrolysers could exceed 8 Mt by 2030. It's an opportunity to take advantage of H2S prospects to be a crucial component of a clean safe and cost-effective sustainable future. This paper assesses the situation regarding H2 at the moment and provides recommendations for its potential future advancement. The study reveals that clean H2 is experiencing significant unparalleled commercial and political force with the amount of laws and projects all over the globe growing quickly. The paper concludes that in order to make H2 more widely employed it is crucial to significantly increase innovations and reduce costs. The practical and implementable suggestions provided to industries and governments will allow them to fully capitalise on this growing momentum.
Correlations between Component Size Green Hydrogen Demand and Breakeven Price for Energy Islands
Jun 2023
Publication
The topic of energy islands is currently a focal point in the push for the energy transition. An ambitious project in the North Sea aims to build an offshore wind-powered electrolyser for green hydrogen production. Power-to-X (PtX) is a process of converting renewable electricity into hydrogen-based energy carriers such as natural gas liquid fuels and chemicals. PtH2 represents a subset of PtX wherein hydrogen is the resultant green energy from the conversion process. Many uncertainties surround PtH2 plants affecting the economic success of the investment and making the price of hydrogen and the levelized cost of hydrogen (LCOH) of this technology uncompetitive. Several studies have analysed PtH2 layouts to identify the hydrogen price without considering how component capacities and external inputs affect the breakeven price. Unlike previous works this paper investigates component capacity dependencies under variables such as wind and hydrogen demand shape for dedicated/non-dedicated system layouts. To this end the techno-economic analysis finds the breakeven price optimising the components to reach the lowest selling price. Results show that the hydrogen price can reach 2.2 €/kg for a non-dedicated system for certain combinations of maximum demand and electrolyser capacity. Furthermore the LCOH analysis revealed that the offshore wind electrolyser system is currently uncompetitive with hydrogen production from carbon-based technologies but is competitive with renewable technologies. The sensitivity analysis reveals the green electricity price in the non-dedicated case for which a dedicated system has a lower optimum hydrogen price. The price limit for the dedicated case is 116 €/MWh.
The Potential Role of a Hydrogen Network in Europe
Jul 2023
Publication
Europe’s electricity transmission expansion suffers many delays despite its significance for integrating renewable electricity. A hydrogen network reusing the existing gas network could not only help to supply the demand for low-emission fuels but could also balance variations in wind and solar energies across the continent and thus avoid power grid expansion. Our investigation varies the allowed expansion of electricity and hydrogen grids in net-zero CO2 scenarios for a sector-coupled European energy system capturing transmission bottlenecks renewable supply and demand variability and pipeline retrofitting and geological storage potentials. We find that a hydrogen network connecting regions with low-cost and abundant renewable potentials to demand centers electrofuel production and cavern storage sites reduces system costs by up to 26 bnV/a (3.4%). Although expanding both networks together can achieve the largest cost reductions by 9.9% the expansion of neither is essential for a net-zero system as long as higher costs can be accepted and flexibility options allow managing transmission bottlenecks.
OIES Podcast - Hydrogen Storage for a Net-zero Carbon Future
May 2023
Publication
In this podcast David Ledesma engages in a conversation with Alex Patonia and Rahmat Poudineh on their recent paper focusing on hydrogen storage for a net-zero carbon future. The podcast delves into the various types of hydrogen storage options highlighting their relative strengths and drawbacks.
In order for a hydrogen economy to be established several key factors must be addressed including efficient and decarbonized production adequate transportation infrastructure and the deployment of suitable hydrogen storage facilities. However hydrogen presents unique challenges when it comes to storage and handling. Due to its extremely low volumetric energy density under ambient conditions hydrogen cannot be efficiently or economically stored without undergoing compression liquefaction or conversion into other more manageable substances.
At present there exist several hydrogen storage solutions at different levels of technology market and commercial readiness each with varying applications depending on specific circumstances.
Additionally the podcast explores the primary barriers that hinder investment in hydrogen storage and the essential components of a viable business model that can address the primary risks to which potential hydrogen storage investors are exposed.
The podcast can be found on their website.
In order for a hydrogen economy to be established several key factors must be addressed including efficient and decarbonized production adequate transportation infrastructure and the deployment of suitable hydrogen storage facilities. However hydrogen presents unique challenges when it comes to storage and handling. Due to its extremely low volumetric energy density under ambient conditions hydrogen cannot be efficiently or economically stored without undergoing compression liquefaction or conversion into other more manageable substances.
At present there exist several hydrogen storage solutions at different levels of technology market and commercial readiness each with varying applications depending on specific circumstances.
Additionally the podcast explores the primary barriers that hinder investment in hydrogen storage and the essential components of a viable business model that can address the primary risks to which potential hydrogen storage investors are exposed.
The podcast can be found on their website.
Optimization of Integrated Energy System Considering Electricity and Hydrogen Coordination in the Context of Carbon Trading
Apr 2024
Publication
In order to improve the consumption of renewable energy and reduce the carbon emissions of integrated energy systems (IESs) this paper proposes an optimal operation strategy for an integrated energy system considering the coordination of electricity and hydrogen in the context of carbon trading. The strategy makes full use of the traditional power-to-gas hydrogen production process and establishes a coupling model comprising cogeneration and carbon capture equipment an electrolytic cell a methane reactor and a hydrogen fuel cell. Taking a minimum daily operating cost and minimal carbon emissions from the system as objective functions a mixed-integer nonlinear optimal scheduling model is established. This paper designs examples based on MATLAB R2021b and uses the GUROBI solver to solve them. The results show that compared with the traditional two-stage operation process the optimization method can reduce the daily operation cost of an IES by 26.01% and its carbon emissions by 90.32%. The results show that the operation mode of electro-hydrogen synergy can significantly reduce the carbon emissions of the system and realize a two-way flow of electro-hydrogen energy. At the same time the addition of carbon capture equipment and the realization of carbon recycling prove the scheduling strategy’s ability to achieve a lowcarbon economy of the scheduling strategy.
A Review on Underground Gas Storage Systems: Natural Gas, Hydrogen and Carbon Sequestration
May 2023
Publication
The concept of underground gas storage is based on the natural capacity of geological formations such as aquifers depleted oil and gas reservoirs and salt caverns to store gases. Underground storage systems can be used to inject and store natural gas (NG) or hydrogen which can be withdrawn for transport to end-users or for use in industrial processes. Geological formations can additionally be used to securely contain harmful gases such as carbon dioxide deep underground by means of carbon capture and sequestration technologies. This paper defines and discusses underground gas storage highlighting commercial and pilot projects and the behavior of different gases (i.e. CH4 H2 and CO2) when stored underground as well as associated modeling investigations. For underground NG/H2 storage the maintenance of optimal subsurface conditions for efficient gas storage necessitates the use of a cushion gas. Cushion gas is injected before the injection of the working gas (NG/H2). The behavior of cushion gas varies based on the type of gas injected. Underground NG and H2 storage systems operate similarly. However compared to NG storage several challenges could be faced during H2 storage due to its low molecular mass. Underground NG storage is widely recognized and utilized as a reference for subsurface H2 storage systems. Furthermore this paper defines and briefly discusses carbon capture and sequestration underground. Most reported studies investigated the operating and cushion gas mixture. The mixture of operating and cushion gas was studied to explore how it could affect the recovered gas quality from the reservoir. The cushion gas was shown to influence the H2 capacity. By understanding and studying the different underground system technologies future directions for better management and successful operation of such systems are thereby highlighted.
Power Sector Effects of Green Hydrogen Production in Germany
Aug 2023
Publication
The use of green hydrogen can support the decarbonization of sectors which are difficult to electrify such as industry or heavy transport. Yet the wider power sector effects of providing green hydrogen are not well understood so far. We use an open-source electricity sector model to investigate potential power sector interactions of three alternative supply chains for green hydrogen in Germany in the year 2030. We distinguish between model settings in which Germany is modeled as an electric island versus embedded in an interconnected system with its neighboring countries as well as settings with and without technology-specific capacity bounds on wind energy. The findings suggest that large-scale hydrogen storage can provide valuable flexibility to the power system in settings with high renewable energy shares. These benefits are more pronounced in the absence of flexibility from geographical balancing. We further find that the effects of green hydrogen production on the optimal generation portfolio strongly depend on the model assumptions regarding capacity expansion potentials. We also identify a potential distributional effect of green hydrogen production at the expense of other electricity consumers of which policy makers should be aware.
Global Demand Analysis for Carbon Dioxide as Raw Material from Key Industrial Sources and Direct Air Capture to Produce Renewable Electricity-based Fuels and Chemicals
Sep 2022
Publication
Defossilisation of the current fossil fuels dominated global energy system is one of the key goals in the upcoming decades to mitigate climate change. Sharp reduction in the costs of solar photovoltaics wind power and battery technologies enables a rapid transition of the power and some segments of the transport sectors to sustainable energy resources. However renewable electricity-based fuels and chemicals are required for the defossilisation of hard-to-abate segments of transport and industry. The global demand for carbon dioxide as raw material for the production of e-fuels and e-chemicals during a global energy transition to 100% renewable energy is analysed in this research. Carbon dioxide capture and utilisation potentials from key industrial point sources including cement mills pulp and paper mills and waste incinerators are evaluated. According to this study’s estimates the demand for carbon dioxide increases from 0.6 in 2030 to 6.1 gigatonnes in 2050. Key industrial point sources can potentially supply 2.1 gigatonnes of carbon dioxide and thus meet the majority of the demand in the 2030s. By 2050 however direct air capture is expected to supply the majority of the demand contributing 3.8 gigatonnes of carbon dioxide annually. Sustainable and unavoidable industrial point sources and direct air capture are vital technologies which may help the world to achieve ambitious climate goals.
Greenhouse Gas Reduction Potential and Economics of Green Hydrogen via Water Electrolysis: A Systematic Review of Value-Chain-Wide Decarbonization
May 2024
Publication
Green hydrogen generated via water electrolysis has become an essential energy carrier for achieving carbon neutrality globally because of its versatility in renewable energy consumption and decarbonization applications in hard-to-abate sectors; however there is a lack of systematic analyses of its abatement potential and economics as an alternative to traditional technological decarbonization pathways. Based on bibliometric analysis and systematic evaluation methods this study characterizes and analyzes the literature on the Web of Science from 1996 to 2023 identifying research hotspots methodological models and research trends in green hydrogen for mitigating climate change across total value chain systems. Our review shows that this research theme has entered a rapid development phase since 2016 with developed countries possessing more scientific results and closer partnerships. Difficult-to-abate sectoral applications and cleaner production are the most famous value chain links and research hotspots focus on three major influencing factors: the environment; techno-economics; and energy. Green hydrogen applications which include carbon avoidance and embedding to realize carbon recycling have considerable carbon reduction potential; however uncertainty limits the influence of carbon reduction cost assessment indicators based on financial analysis methods for policy guidance. The abatement costs in the decarbonization sector vary widely across value chains electricity sources baseline scenarios technology mixes and time scenarios. This review shows that thematic research trends are focused on improving and optimizing solutions to uncertainties as well as studying multisectoral synergies and the application of abatement assessment metrics.
The Necessity and Feasibility of Hydrogen Storage for Large-Scale, Long-Term Energy Storage in the New Power System in China
Jun 2023
Publication
In the process of building a new power system with new energy sources as the mainstay wind power and photovoltaic energy enter the multiplication stage with randomness and uncertainty and the foundation and support role of large-scale long-time energy storage is highlighted. Considering the advantages of hydrogen energy storage in large-scale cross-seasonal and cross-regional aspects the necessity feasibility and economy of hydrogen energy participation in long-time energy storage under the new power system are discussed. Firstly power supply and demand production simulations were carried out based on the characteristics of new energy generation in China. When the penetration of new energy sources in the new power system reaches 45% long-term energy storage becomes an essential regulation tool. Secondly by comparing the storage duration storage scale and application scenarios of various energy storage technologies it was determined that hydrogen storage is the most preferable choice to participate in large-scale and long-term energy storage. Three long-time hydrogen storage methods are screened out from numerous hydrogen storage technologies including salt-cavern hydrogen storage natural gas blending and solid-state hydrogen storage. Finally by analyzing the development status and economy of the above three types of hydrogen storage technologies and based on the geographical characteristics and resource endowment of China it is pointed out that China will form a hydrogen storage system of “solid state hydrogen storage above ground and salt cavern storage underground” in the future.
Thermal Design of a Biohydrogen Production System Driven by Integrated Gasification Combined Cycle Waste Heat Using Dynamic Simulation
Apr 2022
Publication
Utilizing biological processes for hydrogen production via gasification is a promising alternative method to coal gasification. The present study proposes a dynamic simulation model that uses a one-dimensional heat-transfer analysis method to simulate a biohydrogen production system. The proposed model is based on an existing experimental design setup. It is used to simulate a biohydrogen production system driven by the waste heat from an integrated gasification combined cycle (IGCC) power plant equipped with carbon capture and storage technologies. The data from the simulated results are compared with the experimental measurement data to validate the developed model’s reliability. The results show good agreement between the experimental data and the developed model. The relative root-mean-square error for the heat storage feed-mixing and bioreactor tanks is 1.26% 3.59% and 1.78% respectively. After the developed model’s reliability is confirmed it is used to simulate and optimize the biohydrogen production system inside the IGCC power plant. The bioreactor tank’s time constant can be improved when reducing the operating volume of the feed-mixing tank by the scale factors of 0.75 and 0.50 leading to a 15.76% and 31.54% faster time constant respectively when compared with the existing design.
Low-carbon Economy Dispatching of Integrated Energy System with P2G-HGT Coupling Wind Power Absorption Based on Stepped Carbon Emission Trading
Aug 2023
Publication
To improve the renewable energy consumption capacity of integrated energy system (IES) and reduce the carbon emission level of the system a low-carbon economic dispatch model of IES with coupled power-to-gas (P2G) and hydrogen-doped gas units (HGT) under the stepped carbon trading mechanism is proposed. On the premise of wind power output uncertainty the operating characteristics of the coupled electricity-to-gas equipment in the system are used to improve the wind abandonment problem of IES and increase its renewable energy consumption capacity; HGT is introduced to replace the traditional combustion engine for energy supply and on the basis of refined P2G a part of the volume fraction of hydrogen obtained from the production is extracted and mixed with methane to form a gas mixture for HGT combustion so as to improve the low-carbon economy of the system. The ladder type carbon trading mechanism is introduced into IES to guide the system to control carbon emission behavior and reduce the carbon emission level of IES. Based on this an optimal dispatching strategy is constructed with the economic goal of minimizing the sum of system operation cost wind abandonment cost carbon trading cost and energy purchase cost. After linearization of the established model and comparison analysis by setting different scenarios the wind power utilization rate of the proposed model is increased by 24.5% and the wind abandonment cost and CO2 emission are reduced by 86.3% and 10.5% respectively compared with the traditional IES system which achieves the improvement of renewable energy consumption level and low carbon economy.
Hydrogen as a Renewable Energy Carrier in a Hybrid Configuration of Distributed Energy Systems: Bibliometric Mapping of Current Knowledge and Strategies
Jul 2023
Publication
Storing energy in hydrogen deposits balances the operation of energy systems and is an effective tool in the process of energy transformation towards achieving Sustainable Development Goals. To assess the validity of its use as an alternative renewable energy carrier in dispersed energy systems of hybrid configuration a comprehensive review of scientific literature was conducted in this study based on bibliometric analysis. The bibliographic database used in the study was the international Web of Science database. This review contributes to a better understanding of the characteristics of the selected research area. The evolution of research trends implemented in the design of energy systems associated with hydrogen technologies is revealed clearly indicating that it is a developing field. In recent years there has been an increase in the number of publications although the territorial range of research (mainly simulation) conducted in the domain does not include areas with the most favourable infrastructural conditions. The analysis reveals weak cooperation between South American African East Asian and Oceanic countries. In the light of earlier thematically similar literature reviews several research gaps are also identified and proposals for future research are presented. They concern in particular the parallel implementation and optimization of the operation of hydrogen (HRES—Hybrid Renewable Energy System and HESS—Hybrid Energy Storage System) solutions in terms of economics ecology lifespan and work efficiency as well as their feasibility analysis. With the support of other researchers and those involved in the subject matter this review may contribute to the further development of hybrid hydrogen systems in terms of increasing competitiveness and promoting the implementation of these technologies.
Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures
Sep 2018
Publication
Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed and the particles were degraded during the reduction. Finally sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore the variation of activation energy value was smoothed after heat treatment of hematite particles.
Designing a Future-proof Gas and Hydrogen Infrastructure for Europe - A Modelling-based Approach
Jun 2023
Publication
Hydrogen has been at the centre of attention since the EU kicked-off its decarbonization agenda at full speed. Many consider it a silver bullet for the deep decarbonization of technically challenging sectors and industries but it is also an attractive option for the gas industry to retain and future-proof its well-developed infrastructure networks. The modelling methodology presented in this report systematically tests the feasibility and cost of different pipeline transportation methods – blending repurposing and dedicated hydrogen pipelines - under different decarbonization pathways and concludes that blending is not a viable solution and pipeline repurposing can lead to excessive investment outlays in the range of EUR 19–25 bn over the modelled period (2020–2050) for the EU-27.
Advancements in Hydrogen Energy Systems: A Review of Levelized Costs, Financial Incentives and Technological Innovations
Apr 2024
Publication
Hydrogen energy systems (HES) are increasingly recognized as pivotal in cutting global carbon dioxide (CO2) emissions especially in transportation power generation and industrial sectors. This paper offers a comprehensive review of HES emphasizing their diverse applications and economic viability. By 2030 hydrogen energy is expected to revolutionize various sectors significantly impacting CO2 abatement and energy demand. In electricity and power generation hydrogen could reduce CO2 emissions by 50–100 million tons annually requiring 10–20 million tons of hydrogen and an investment of $50–100 billion underscoring its role in grid stabilization. Additionally in the heating sector hydrogen could facilitate a CO2 abatement of 30–50 million tons. We examine the levelized cost of hydrogen (LCOH) production influenced by factors like production methods efficiency and infrastructure. While steam methane reforming is cost-effective it poses a larger environmental impact compared to electrolysis. The global life-cycle cost of hydrogen production decreases as production scales up with current costs ranging from $1–3 per kg for fossil-based sources to $3.4–7.5 per kg for electrolysis using low-emission electricity. These costs are projected to decrease especially for electrolytic hydrogen in regions with abundant solar energy. However despite the technical feasibility of decarbonization high production costs still pose challenges. A systematic and effective transition to a hydrogen economy requires comprehensive policy and financial support mechanisms including incentives subsidies tax measures and funding for research and development of pilot projects. Additionally the paper discusses hydrogen's role in advanced storage technologies such as hydrides and Japan's ENE-FARM solution for residential energy emphasizing the need for strategic investments across the hydrogen value chain to enhance HES competitiveness reduce LCOH and advance the learning rates of hydrogen production technologies.
Critical Review of Life Cycle Assessment of Hydrogen Production Pathways
May 2024
Publication
In light of growing concerns regarding greenhouse gas emissions and the increasingly severe impacts of climate change the global situation demands immediate action to transition towards sustainable energy solutions. In this sense hydrogen could play a fundamental role in the energy transition offering a potential clean and versatile energy carrier. This paper reviews the recent results of Life Cycle Assessment studies of different hydrogen production pathways which are trying to define the routes that can guarantee the least environmental burdens. Steam methane reforming was considered as the benchmark for Global Warming Potential with an average emission of 11 kgCO2eq/kgH2. Hydrogen produced from water electrolysis powered by renewable energy (green H2 ) or nuclear energy (pink H2 ) showed the average lowest impacts with mean values of 2.02 kgCO2eq/kgH2 and 0.41 kgCO2eq/kgH2 respectively. The use of grid electricity to power the electrolyzer (yellow H2 ) raised the mean carbon footprint up to 17.2 kgCO2eq/kgH2 with a peak of 41.4 kgCO2eq/kgH2 in the case of countries with low renewable energy production. Waste pyrolysis and/or gasification presented average emissions three times higher than steam methane reforming while the recourse to residual biomass and biowaste significantly lowered greenhouse gas emissions. The acidification potential presents comparable results for all the technologies studied except for biomass gasification which showed significantly higher and more scattered values. Regarding the abiotic depletion potential (mineral) the main issue is the lack of an established recycling strategy especially for electrolysis technologies that hamper the inclusion of the End of Life stage in LCA computation. Whenever data were available hotspots for each hydrogen production process were identified.
Advantages and Technological Progress of Hydrogen Fuel Cell Vehicles
Jun 2023
Publication
The automotive industry is undergoing a profound transformation driven by the need for sustainable and environmentally friendly transportation solutions [1]. In this context fuel cell technology has emerged as a promising alternative offering clean efficient and high-performance power sources for vehicles [2]. Fuel cell vehicles are electric vehicles that use fuel cell systems as a single power source or as a hybrid power source in combination with rechargeable energy storage systems. A typical fuel cell system for electric vehicle is exhibited in Figure 1 which provides a comprehensive demonstration of this kind of complex system. Hydrogen energy is a crucial field in the new energy revolution and will become a key pillar in building a green efficient and secure new energy system. As a critical field for hydrogen utilization fuel cell vehicles will play an important role in the transformation and development of the automotive industry. The development of fuel cell vehicles offers numerous advantages such as strong power outputs safety reliability and economic energy savings [3]. However improvements must urgently be made in existing technologies such as fuel cell stacks (including proton exchange membranes catalysts gas diffusion layers and bipolar plates) compressors and onboard hydrogen storage systems [4]. The advantages and current technological status are analyzed here.
Biogas Reforming as a Sustainable Solution for Hydrogen Production: Comparative Environmental Metrics with Steam-methane Reforming and Water Electrolysis in the Portuguese Context
Apr 2024
Publication
This study delves into the dynamics of hydrogen production with a specific focus on biogas reforming (BGSMR) for hydrogen generation. It compares the environmental impact of this solution with hydrogen production from natural gas-steam reforming (NGSMR) and commercial electrolysis in the Portuguese context. Various metrics including carbon footprint water depletion energy utilization and waste valorization are employed for a comprehensive comparison. The assessment explores the impact of operational parameters and different off-gas combustion scenarios incorporating water recycling practices. Due to challenges in obtaining detailed data on the actual reforming process the study relies on process simulation techniques primarily using DWSIM. Commercially available data for water electrolysers were used for comparison. In the context of decarbonizing power systems hydrogen from water electrolysis emerges as a competitive option only in a scenario where the power system is 100% reliant on renewable sources particularly with respect to the carbon footprint metric. Biogas systems characterized by near-zero carbon emissions stand out as a favourable option from the near future to the long run. This research contributes valuable insights into the dynamics of hydrogen production shedding light on environmentally viable alternatives across a range of power system scenarios.
Techno-Economic Assessment of a Full-Chain Hydrogen Production by Offshore Wind Power
May 2024
Publication
Offshore wind power stands out as a promising renewable energy source offering substantial potential for achieving low carbon emissions and enhancing energy security. Despite its potential the expansion of offshore wind power faces considerable constraints in offshore power transmission. Hydrogen production derived from offshore wind power emerges as an efficient solution to overcome these limitations and effectively transport energy. This study systematically devises diverse hydrogen energy supply chains tailored to the demands of the transportation and chemical industries meticulously assessing the levelized cost of hydrogen (LCOH). Our findings reveal that the most cost-efficient means of transporting hydrogen to the mainland is through pipelines particularly when the baseline distance is 50 km and the baseline electricity price is 0.05 USD/kWh. Notably delivering hydrogen directly to the port via pipelines for chemical industries proves considerably more economical than distributing it to hydrogen refueling stations with a minimal cost of 3.6 USD/kg. Additionally we assessed the levelized cost of hydrogen (LCOH) for supply chains that transmit electricity to ports via submarine cables before hydrogen production and subsequent distribution to chemical plants. In comparison to offshore hydrogen production routes these routes exhibit higher costs and reduced competitiveness. Finally a sensitivity analysis was undertaken to scrutinize the impact of delivery distance and electricity prices on LCOH. The outcomes underscore the acute sensitivity of LCOH to power prices highlighting the potential for substantial reductions in hydrogen prices through concerted efforts to lower electricity costs.
Deep Decarbonisation Pathways of the Energy System in Times of Unprecedented Uncertainty in the Energy Sector
May 2023
Publication
Unprecedented investments in clean energy technology are required for a net-zero carbon energy system before temperatures breach the Paris Agreement goals. By performing a Monte-Carlo Analysis with the detailed ETSAPTIAM Integrated Assessment Model and by generating 4000 scenarios of the world’s energy system climate and economy we find that the uncertainty surrounding technology costs resource potentials climate sensitivity and the level of decoupling between energy demands and economic growth influence the efficiency of climate policies and accentuate investment risks in clean energy technologies. Contrary to other studies relying on exploring the uncertainty space via model intercomparison we find that the CO2 emissions and CO2 prices vary convexly and nonlinearly with the discount rate and climate sensitivity over time. Accounting for this uncertainty is important for designing climate policies and carbon prices to accelerate the transition. In 70% of the scenarios a 1.5 ◦C temperature overshoot was within this decade calling for immediate policy action. Delaying this action by ten years may result in 2 ◦C mitigation costs being similar to those required to reach the 1.5 ◦C target if started today with an immediate peak in emissions a larger uncertainty in the medium-term horizon and a higher effort for net-zero emissions.
Optimization of Small-Scale Hydrogen Production with Membrane Reactors
Mar 2023
Publication
In the pathway towards decarbonization hydrogen can provide valid support in different sectors such as transportation iron and steel industries and domestic heating concurrently reducing air pollution. Thanks to its versatility hydrogen can be produced in different ways among which steam reforming of natural gas is still the most commonly used method. Today less than 0.7% of global hydrogen production can be considered low-carbon-emission. Among the various solutions under investigation for low-carbon hydrogen production membrane reactor technology has the potential especially at a small scale to efficiently convert biogas into green hydrogen leading to a substantial process intensification. Fluidized bed membrane reactors for autothermal reforming of biogas have reached industrial maturity. Reliable modelling support is thus necessary to develop their full potential. In this work a mathematical model of the reactor is used to provide guidelines for their design and operations in off-design conditions. The analysis shows the influence of temperature pressures catalyst and steam amounts and inlet temperature. Moreover the influence of different membrane lengths numbers and pitches is investigated. From the results guidelines are provided to properly design the geometry to obtain a set recovery factor value and hydrogen production. For a given reactor geometry and fluidization velocity operating the reactor at 12 bar and the permeate-side pressure of 0.1 bar while increasing reactor temperature from 450 to 500 °C leads to an increase of 33% in hydrogen production and about 40% in HRF. At a reactor temperature of 500 °C going from 8 to 20 bar inside the reactor doubled hydrogen production with a loss in recovery factor of about 16%. With the reactor at 12 bar a vacuum pressure of 0.5 bar reduces hydrogen production by 43% and HRF by 45%. With the given catalyst it is sufficient to have only 20% of solids filled into the reactor being catalytic particles. With the fixed operating conditions it is worth mentioning that by adding membranes and maintaining the same spacing it is possible to increase hydrogen production proportionally to the membrane area maintaining the same HRF.
Development of Hydrogen Area Classification Data for Use in Village Trials
May 2023
Publication
The natural gas industry proposes carrying out trials on limited parts of the gas network using hydrogen as an alternative to natural gas as a fuel. Ahead of these trials it is important to establish whether the zones of negligible extent that are typically applied to natural gas systems could still be considered zones of negligible extent for hydrogen. The standard IGEM/UP/16 is commonly used by the natural gas industry to carry out area classification for low pressure gas systems for example as found in boiler houses. However IGEM/UP/16 is not applicable to hydrogen. Therefore IGEM commissioned HSE’s Science Division to develop some data that could be used to feed into an area classification assessment for the village trials.<br/>This report identifies two main elements of IGEM/UP/16 which may not apply to hydrogen and suggests values for hydrogen-specific alternatives. These are the ventilation rate requirements to allow a zone to be deemed of negligible extent and the definition of a confined space.
An Economic and Greenhouse Gas Footprint Assessment of International Maritime Transportation of Hydrogen Using Liquid Organic Hydrogen Carriers
Apr 2023
Publication
The supply storage and (international) transport of green hydrogen (H2) are essential for the decarbonization of the energy sector. The goal of this study was to assess the final cost-price and carbon footprint of imported green H2 in the market via maritime shipping of liquid organic hydrogen carriers (LOHCs) including dibenzyl toluene-perhydro-dibenzyltoluene (DBTPDBT) and toluene-methylcyclohexane (TOL-MCH) systems. The study focused on logistic steps in intra-European supply chains in different scenarios of future production in Portugal and demand in the Netherlands and carbon tariffs between 2030 and 2050. The case study is based on a formally accepted agreement between Portugal and the Netherlands within the Strategic Forum on Important Projects of Common European Interest (IPCEI). Under the following assumptions the results show that LOHCs are a viable technical-economic solution with logistics costs from 2030 to 2050 varying between 0.30-0.37 €/kg-H2 for DBT-PDBT and 0.28-0.34 €/kg-H2 for TOL-MCH. The associated CO2 emissions of these international H2 supply chains are between 0.46 and 2.46 kg-CO2/GJ (LHV) and 0.55-2.95 kg-CO2/GJ (LHV) for DBT-PDBT and TOL-MCH respectively.
Techno-economic Viability of Islanded Green Ammonia as a Carbon-free Energy Vector and as a Substitute for Conventional Production
Jul 2020
Publication
Decarbonising ammonia production is an environmental imperative given that it independently accounts for 1.8% of global carbon dioxide emissions and supports the feeding of over 48% of the global population. The recent decline of production costs and its potential as an energy vector warrant investigation of whether green ammonia production is commercially competitive. Considering 534 locations in 70 countries and designing and operating the islanded production process to minimise the levelised cost of ammonia (LCOA) at each we show the range of achievable LCOA the cost of process flexibility the components of LCOA and therein the scope of LCOA reduction achievable at present and in 2030. These results are benchmarked against ammonia spot prices cost per GJ of refined fuels and the LCOE of alternative energy storage methods. Currently a LCOA of $473 t1 is achievable at the best locations the required process flexibility increases the achievable LCOA by 56%; the electrolyser CAPEX and operation are the most significant costs. By 2030 $310 t1 is predicted to be achievable with multiple locations below $350 t1 . At $25.4 GJ11 ) that do not have the benefit of being carbon-free.
Exploring the Potential of Green Hydrogen Production and Application in the Antofagasta Region of Chile
Jun 2023
Publication
Green hydrogen is gaining increasing attention as a key component of the global energy transition towards a more sustainable industry. Chile with its vast renewable energy potential is well positioned to become a major producer and exporter of green hydrogen. In this context this paper explores the prospects for green hydrogen production and use in Chile. The perspectives presented in this study are primarily based on a compilation of government reports and data from the scientific literature which primarily offer a theoretical perspective on the efficiency and cost of hydrogen production. To address the need for experimental data an ongoing experimental project was initiated in March 2023. This project aims to assess the efficiency of hydrogen production and consumption in the Atacama Desert through the deployment of a mobile on-site laboratory for hydrogen generation. The facility is mainly composed by solar panels electrolyzers fuel cells and a battery bank and it moves through the Atacama Desert in Chile at different altitudes from the sea level to measure the efficiency of hydrogen generation through the energy approach. The challenges and opportunities in Chile for developing a robust green hydrogen economy are also analyzed. According to the results Chile has remarkable renewable energy resources particularly in solar and wind power that could be harnessed to produce green hydrogen. Chile has also established a supportive policy framework that promotes the development of renewable energy and the adoption of green hydrogen technologies. However there are challenges that need to be addressed such as the high capital costs of green hydrogen production and the need for supportive infrastructure. Despite these challenges we argue that Chile has the potential to become a leading producer and exporter of green hydrogen or derivatives such as ammonia or methanol. The country’s strategic location political stability and strong commitment to renewable energy provide a favorable environment for the development of a green hydrogen industry. The growing demand for clean energy and the increasing interest in decarbonization present significant opportunities for Chile to capitalize on its renewable energy resources and become a major player in the global green hydrogen market.
Research on Energy Management Method of Fuel Cell/Supercapacitor Hybrid Trams Based on Optimal Hydrogen Consumption
Jul 2023
Publication
In this paper based on the operating states and characteristics of fuel cell/supercapacitor hybrid trams an optimal hydrogen energy management method is proposed. This method divides the operating states into two parts: traction state and non-traction state. In the traction state the real-time loss function of the hybrid power system which is used to obtain the fuel cell optimal output power under the different demand powers and supercapacitor voltage is established. In the non-traction state the constant-power charging method which is obtained by solving the power-voltage charging model is used to ensure the supercapacitor voltage of the beginning-state and the end-state in an entire operation cycle are the same. The RT-LAB simulation platform is used to verify that the proposed method has the ability to control the hybrid real-time system. Using the comparative experiment between the proposed method and power-follow method the results show that the proposed method offers a significant improvement in both fuel cell output stability and hydrogen consumption in a full operation cycle.
Forecasting Hydrogen Vehicle Refuelling for Sustainable Transportation: A Light Gradient-Boosting Machine Model
May 2024
Publication
Efficiently predicting and understanding refuelling patterns in the context of HFVs is paramount for optimising fuelling processes infrastructure planning and facilitating vehicle operation. This study evaluates several supervised machine learning methodologies for predicting the refuelling behaviour of HFVs. The LightGBM model emerged as the most effective predictive model due to its ability to handle time series and seasonal data. The selected model integrates various input variables encompassing refuelling metrics day of the week and weather conditions (e.g. temperature precipitation) to capture intricate patterns and relationships within the data set. Empirical testing and validation against real-world refuelling data underscore the efficacy of the LightGBM model demonstrating a minimal deviation from actual data given limited data and thereby showcasing its potential to offer valuable insights to fuelling station operators vehicle manufacturers and policymakers. Overall this study highlights the potential of sustainable predictive modelling for optimising fuelling processes infrastructure planning and facilitating vehicle operation in the context of HFVs.
Gas Goes Green: Britain's Hydrogen Blending Delivery Plan
Jan 2022
Publication
Britain’s Hydrogen Blending Delivery Plan which sets out how all five of Britain’s gas grid companies will meet the Government’s target for Britain’s network of gas pipes to be ready to deliver 20% hydrogen to homes and businesses from 2023 as a replacement for natural gas.
Key Considerations for Evaluating Underground Hydrogen Storage (UHS) Potential in Five Contrasting Australian Basins
Apr 2024
Publication
Hydrogen gas can provide baseload energy as society decarbonizes through the energy transition. Underground Hydrogen Storage (UHS) will be secure convenient and scalable to accommodate excess hydrogen production or compensate temporary shortfalls in energy supply. Hydrogen is a gas under all viable subsurface conditions so is invasive mobile and low-density. Methane and CO2 are also stored underground but storage parameters differ for each affecting the balance of geological storage risks. UHS in Australia is most likely to utilise conventional sedimentary reservoir rocks bound by conventional trapping closures. Hydrogen energy density will affect the competitiveness of UHS against purpose-built surface storage or solution-mined salt cavities. This study presents an overview of key considerations when screening for UHS opportunities and evaluates them for five Australian sedimentary basins. A threshold storage depth mapped across them reveals that the most prospective UHS basins will have to function as integrated energy fluid resource systems.
Technology Portfolio Assessment for Near-zero Emission Iron and Steel Industry in China
May 2023
Publication
China aims to peak CO2 emissions before 2030 and to achieve carbon neutrality before 2060; hence industrial sectors in China are keen to figure out appropriate pathways to support the national target of carbon neutrality. The objective of this study is to explore near-zero emission pathways for the steel industry of China through a detailed technology assessment. The innovative technology development has been simulated using the AIM-China/steel model developed by including material-based technologies and optimal cost analysis. Six scenarios have been given in terms of different levels of production output emission reduction and carbon tax. Near-zero emission and carbon tax scenarios have shown that China’s steel industry can achieve near-zero emission using electric furnaces and hydrogen-based direct reduction iron technologies with policy support. Based on these technologies minimised production costs have been calculated revealing that the steel produced by these technologies is cost-effective. Moreover the feedstock cost can play a key role in these technology portfolios especially the cost of scrap iron ore and hydrogen. In addition the feedstock supply can have strong regional effects and can subsequently impact the allocation of steelmaking in the future. Therefore China can achieve near-zero emissions in the steel industry and electric furnace and hydrogen-based direct reduction iron technologies are crucial to achieving them.
Semi-Systematic Literature Review on the Contribution of Hydrogen to Universal Access to Energy in the Rationale of Sustainable Development Goal Target 7.1
Feb 2023
Publication
As part of the United Nations’ (UN) Sustainable Development Goal 7 (SDG7) SDG target 7.1 recognizes universal electrification and the provision of clean cooking fuel as two fundamental challenges for global society. Faltering progress toward SDG target 7.1 calls for innovative technologies to stimulate advancements. Hydrogen has been proposed as a versatile energy carrier to be applied in both pillars of SDG target 7.1: electrification and clean cooking. This paper conducts a semi-systematic literature review to provide the status quo of research on the application of hydrogen in the rationale of SDG 7.1 covering the technical integration pathways as well as the key economic environmental and social aspects of its use. We identify decisive factors for the future development of hydrogen use in the rationale of SDG target 7.1 and by complementing our analysis with insights from the related literature propose future avenues of research. The literature on electrification proposes that hydrogen can serve as a backup power supply in rural off-grid communities. While common electrification efforts aim to supply appliances that use lower amounts of electricity a hydrogen-based power supply can satisfy appliances with higher power demands including electric cook stoves while simultaneously supporting clean cooking efforts. Alternatively with the exclusive aim of stimulating clean cooking hydrogen is proposed to be used as a clean cooking fuel via direct combustion in distribution and utilization infrastructures analogous to Liquid Petroleum Gas (LPG). While expected economic and technical developments are seen as likely to render hydrogen technologies economically competitive with conventional fossil fuels in the future the potential of renewably produced hydrogen usage to reduce climate-change impacts and point-of-use emissions is already evident today. Social benefits are likely when meeting essential safety standards as a hydrogen-based power supply offers service on a high tier that might overachieve SDG 7.1 ambitions while hydrogen cooking via combustion fits into the existing social habits of LPG users. However the literature lacks clear evidence on the social impact of hydrogen usage. Impact assessments of demonstration projects are required to fill this research gap.
Behavior of Barrier Wall under Hydrogen Storage Tank Explosion with Simulation and TNT Equivalent Weight Method
Mar 2023
Publication
Hydrogen gas storage place has been increasing daily because of its consumption. Hydrogen gas is a dream fuel of the future with many social economic and environmental benefits to its credit. However many hydrogen storage tanks exploded accidentally and significantly lost the economy infrastructure and living beings. In this study a protection wall under a worst-case scenario explosion of a hydrogen gas tank was analyzed with commercial software LS-DYNA. TNT equivalent method was used to calculate the weight of TNT for Hydrogen. Reinforced concrete and composite protection wall under TNT explosion was analyzed with a different distance of TNT. The initial dimension of the reinforced concrete protection wall was taken from the Korea gas safety code book (KGS FP217) and studied the various condition. H-beam was used to make the composite protection wall. Arbitrary-Lagrangian-Eulerian (ALE) simulation from LS-DYNA and ConWep pressure had a good agreement. Used of the composite structure had a minimum displacement than a normal reinforced concrete protection wall. During the worst-case scenario explosion of a hydrogen gas 300 kg storage tank the minimum distance between the hydrogen gas tank storage and protection wall should be 3.6 m.
An Approach for Sizing a PV-battery-electrolyzer-fuel cell Energy System: A Cast Study at a Field Lab
May 2023
Publication
Hydrogen is becoming increasingly popular as a clean secure and affordable energy source for the future. This study develops an approach for designing a PV–battery–electrolyzer–fuel cell energy system that utilizes hydrogen as a long-term storage medium and battery as a short-term storage medium. The system is designed to supply load demand primarily through direct electricity generation in the summer and indirect electricity generation through hydrogen in the winter. The sizing of system components is based on the direct electricity and indirect hydrogen demand with a key input parameter being the load sizing factor which determines the extent to which hydrogen is used to meet seasonal imbalance. Technical and financial indicators are used to assess the performance of the designed system. Simulation results indicate that the energy system can effectively balance the seasonal variation of renewable generation and load demand with the use of hydrogen. Additionally guidelines for achieving self-sufficiency and system sustainability for providing enough power in the following years are provided to determine the appropriate component size. The sensitivity analysis indicates that the energy system can achieve self-sufficiency and system sustainability with a proper load sizing factor from a technical perspective. From an economic perspective the levelized cost of energy is relatively high because of the high costs of hydrogen-related components at this moment. However it has great economic potential for future self-sufficient energy systems with the maturity of hydrogen technologies.
Current Development Status, Policy Support and Promotion Path of China’s Green Hydrogen Industries under the Target of Carbon Emission Peaking and Carbon Neutrality
Jun 2023
Publication
The green hydrogen industry highly efficient and safe is endowed with flexible production and low carbon emissions. It is conducive to building a low-carbon efficient and clean energy structure optimizing the energy industry system and promoting the strategic transformation of energy development and enhancing energy security. In order to achieve carbon emission peaking by 2030 and neutrality by 2060 (dual carbon goals) China is vigorously promoting the green hydrogen industry. Based on an analysis of the green hydrogen industry policies of the U.S. the EU and Japan this paper explores supporting policies issued by Chinese central and local authorities and examines the inherent advantages of China’s green hydrogen industry. After investigating and analyzing the basis for the development of the green hydrogen industry in China we conclude that China has enormous potential including abundant renewable energy resources as well as commercialization experience with renewable energy robust infrastructure and technological innovation capacity demand for large-scale applications of green hydrogen in traditional industries etc. Despite this China’s green hydrogen industry is still in its early stage and has encountered bottlenecks in its development including a lack of clarity on the strategic role and position of the green hydrogen industry low competitiveness of green hydrogen production heavy reliance on imports of PEMs perfluorosulfonic acid resins (PFSR) and other core components the development dilemma of the industry chain lack of installed capacity for green hydrogen production and complicated administrative permission etc. This article therefore proposes that an appropriate development road-map and integrated administration supervision systems including safety supervision will systematically promote the green hydrogen industry. Enhancing the core technology and equipment of green hydrogen and improving the green hydrogen industry chain will be an adequate way to reduce dependence on foreign technologies lowering the price of green hydrogen products through the scale effect and thus expanding the scope of application of green hydrogen. Financial support mechanisms such as providing tax breaks and project subsidies will encourage enterprises to carry out innovative technological research on and invest in the green hydrogen industry.
Biohydrogen Production from Biomass Sources: Metabolic Pathways and Economic Analysis
Sep 2021
Publication
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.
Global Green Hydrogen-based Steel Opportunities Surrounding High Quality Renewable Energy and Iron Ore Deposits
May 2023
Publication
The steel sector currently accounts for 7% of global energy-related CO2 emissions and requires deep reform to disconnect from fossil fuels. Here we investigate the market competitiveness of one of the widely considered decarbonisation routes for primary steel production: green hydrogen-based direct reduction of iron ore followed by electric arc furnace steelmaking. Through analysing over 300 locations by combined use of optimisation and machine learning we show that competitive renewables-based steel production is located nearby the tropic of Capricorn and Cancer characterised by superior solar with supplementary onshore wind in addition to high-quality iron ore and low steelworker wages. If coking coal prices remain high fossil-free steel could attain competitiveness in favourable locations from 2030 further improving towards 2050. Large-scale implementation requires attention to the abundance of suitable iron ore and other resources such as land and water technical challenges associated with direct reduction and future supply chain configuration.
Probabilistic Modelling of Seasonal Energy Demand Patterns in the Transition from Natural Gas to Hydrogen for an Urban Energy District
May 2023
Publication
The transition to a low-carbon energy system can be depicted as a “great reconfiguration” from a socio-technical perspective that carries the risk of impact shifts. Electrification with the objective of achieving rapidly deep decarbonisation must be accompanied by effective efficiency and flexibility measures. Hydrogen can be a preferred option in the decarbonisation process where electrification of end-uses is difficult or impractical as well as for long-term storage in energy infrastructure characterised by a large penetration of renewable energy sources. Notwithstanding the current uncertainties regarding costs environmental impact and the inherent difficulties of increasing rapidly supply capacity hydrogen can represent a solution to be used in multi-energy systems with combined heat and power (CHP) in particular in urban energy districts. In fact while achieving carbon savings with natural gas fuelled CHP is not possible when low grid carbon intensity factors are present it may still be possible to use it to provide flexibility services and to reduce emissions further with switch from natural gas to hydrogen. In this paper a commercially established urban district energy scheme located in Southampton (United Kingdom) is analysed with the goal of exploring potential variations in its energy demand. The study proposes the use of scalable data-driven methods and probabilistic simulation to generate seasonal energy demand patterns representing the potential short-term and long-term evolution of the energy district.
Analysis of Crash Characteristics of Hydrogen Storage Structure of Hydrogen Powered UAV
Nov 2022
Publication
In the context of green aviation as an internationally recognized solution hydrogen energy is lauded as the “ultimate energy source of the 21st century” with zero emissions at the source. Developed economies with aviation industries such as Europe and the United States have announced hydrogen energy aviation development plans successively. The study and development of high-energy hydrogen fuel cells and hydrogen energy power systems have become some of the future aviation research focal points. As a crucial component of hydrogen energy storage and delivery the design and development of a safe lightweight and efficient hydrogen storage structure have drawn increasing consideration. Using a hydrogen-powered Unmanned Aerial Vehicle (UAV) as the subject of this article the crash characteristics of the UAV’s hydrogen storage structure are investigated in detail. The main research findings are summarized as follows: (1) A series of crash characteristics analyses of the hydrogen storage structure of a hydrogen-powered UAV were conducted and the Finite Element Analysis (FEA) response of the structure under different impact angles internal pressures and impact speeds was obtained and analyzed. (2) When the deformation of the hydrogen storage structure exceeds 50 mm and the strain exceeds 0.8 an initial crack will appear at this part of the hydrogen storage structure. The emergency release valve should respond immediately to release the gas inside the tank to avoid further damage. (3) Impact angle and initial internal pressure are the main factors affecting the formation of initial cracks.
The Role of Liquid Hydrogen in Integrated Energy Systems - A Case Study for Germany
May 2023
Publication
Hydrogen (H2) is expected to be a key building block in future greenhouse gas neutral energy systems. This study investigates the role of liquid hydrogen (LH2) in a national greenhouse gas-neutral energy supply system for Germany in 2045. The integrated energy system model suite ETHOS is extended by LH2 demand profiles in the sectors aviation mobility and chemical industry and means of LH2 transportation via inland vessel rail and truck. This case study demonstrates that the type of hydrogen demand (liquid or gaseous) can strongly affect the cost-optimal design of the future energy system. When LH2 demand is introduced to the energy system LH2 import transportation and production grow in importance. This decreases the need for gaseous hydrogen (GH2) pipelines and affects the location of H2 production plants. When identifying no-regret measures it must be considered that the largest H2 consumers are the ones with the highest readiness to use LH2.
A Low-temperature Ammonia Electrolyser for Wastewater Treatment and Hydrogen Production
May 2023
Publication
Ammonia is a pollutant present in wastewater and is also a valuable carbon-free hydrogen carrier. Stripping recovery and anodic oxidation of ammonia to produce hydrogen via electrolysis is gaining momentum as a technology yet the development of an inexpensive stable catalytic material is imperative to reduce cost. Here we report on a new nickel copper (NiCu) catalyst electrodeposited onto a high surface area nickel felt (NF) as an anode for ammonia electrolysis. Cyclic voltammetry demonstrated that the catalyst/substrate combination reached the highest current density (200 mA cm2 at 20 C) achieved for a non-noble metal catalyst. A NiCu/NF electrode was tested in an anion exchange membrane electrolyser for 50 h; it showed good stability and high Faradaic efficiency for ammonia oxidation (88%) and hydrogen production (99%). We demonstrate that this novel electrode catalyst/substrate material combination can oxidise ammonia in a scaled system and hydrogen can be produced as a valuable by-product at industrial-level current densities and cell voltages lower than that for water electrolysis.
Performance, Emissions, and Economic Analyses of Hydrogen Fuel Cell Vehicles
May 2024
Publication
The transport sector is considered to be a significant contributor to greenhouse gas emissions as this sector emits about one-fourth of global CO2 emissions. Transport emissions contribute toward climate change and have been linked to adverse health impacts. Therefore alternative and sustainable transport options are urgent for decarbonising the transport sector and mitigating those issues. Hydrogen fuel cell vehicles are a potential alternative to conventional vehicles which can play a significant role in decarbonising the future transport sector. This study critically analyses the recent works related to hydrogen fuel cell integration into vehicles modelling and experimental investigations of hydrogen fuel cell vehicles with various powertrains. This study also reviews and analyses the performance energy management strategies lifecycle cost and emissions of fuel cell vehicles. Previous literature suggested that the fuel consumption and well-to-wheel greenhouse gas emissions of hydrogen fuel cell-powered vehicles are significantly lower than that of conventional internal combustion vehicles. Hydrogen fuel cell vehicles consume about 29–66 % less energy and cause approximately 31–80 % less greenhouse gas emissions than conventional vehicles. Despite this the lifecycle cost of hydrogen fuel cell vehicles has been estimated to be 1.2–12.1 times higher than conventional vehicles. Even though there has been recent progress in energy management in hydrogen fuel cell electric vehicles there are a number of technical and economic challenges to the commercialisation of hydrogen fuel cell vehicles. This study presents current knowledge gaps and details future research directions in relation to the research advancement of hydrogen fuel cell vehicles.
CFD Modelling of Startup Fuelling Phase Accounting for All Hydrogen Refuelling Station Components
Sep 2023
Publication
Further development of hydrogen-fuelled transport and associated infrastructure requires fundamentally based validated and publicly accepted models for fuelling protocol development particularly for heavy-duty transport applications where protocols are not available yet. This study aims to use computational fluid dynamics (CFD) for modelling the entire hydrogen refuelling station (HRS) including all its components starting from high-pressure (HP) tanks a mass flow meter pressure control valve (PCV) a heat exchanger (HE) nozzle hose breakaway and up to 3 separate onboard tanks. The paper focuses on the initial phase of the refuelling procedure in which the main purpose is to check for leaks in the fuelling line and determine if it is safe to start fuelling. The simulation results are validated against the only publicly available data on hydrogen fuelling by Kuroki and co-authors (2021) from the NREL hydrogen fuelling station experiment. The simulation results – mass flow rate dynamics as well as pressure and temperature at different station locations - show good agreement with the measured experimental data. The development of such models is crucial for the further advancement of hydrogen-fuelled transport and infrastructure and this study presents a step towards this goal.
THyGA - Test Report on Mitigation Solutions for Residential Natural Gas Appliances Not Designed for Hydrogen Admixture
Apr 2023
Publication
This report from the WP5 “Mitigation” provides information and test results regarding perturbations that hydrogen could cause to gas appliances when blended to natural gas especially on anatural draught for exhaust fumes or acidity for the condensates. The important topic of on-site adjustment is also studied with test results on alternative technologies and proposals of mitigation approaches.
A Techno-economic Study of the Strategy for Hydrogen Transport by Pipelines in Canada
Jan 2023
Publication
Hydrogen as a clean zero-emission energy fuel will play a critical role in energy transition and achievement of the net-zero target in 2050. Hydrogen delivery is integral to the entire value chain of a full-scale hydrogen economy. This work conducted a systematic review and analysis of various hydrogen transportation methods including truck tankers for liquid hydrogen tube trailers for gaseous hydrogen and pipelines by identifying and ranking the main properties and affecting factors associated with each method. It is found that pipelines especially the existing natural gas pipelines provide a more efficient and cheaper means to transport hydrogen over long distances. Analysis was further conducted on Canadian natural gas pipeline network which has been operating for safe effective and efficient energy transport over six decades. The established infrastructure along with the developed operating and management experiences and skillful manpower makes the existing pipelines the best option for transport of hydrogen in either blended or pure form in the country. The technical challenges in repurposing the existing natural gas pipelines for hydrogen service were discussed and further work was analyzed.
Study on the Dynamic Optimal Control Strategy of an Electric-Hydrogen Hybrid Energy Storage System for a Direct Drive Wave Power Generation System
Jul 2023
Publication
A direct drive wave power generation system (DDWPGS) has the advantages of a simple structure and easy deployment and is the first choice to provide electricity for islands and operation platforms in the deep sea. However due to the off-grid the source and load cannot be matched so accommodation is an important issue. Hydrogen storage is the optimal choice for offshore wave energy accommodation. Therefore aiming at the source-load mismatch problem of the DDWPGS an electric-hydrogen hybrid energy storage system (HESS) for the DDWPGS is designed in this paper. Based on the characteristics of the devices in the electric-hydrogen HESS a new dynamic power allocation strategy and its control strategy are proposed. Firstly empirical mode decomposition (EMD) is utilized to allocate the power fluctuations that need to be stabilized. Secondly with the state of charge (SOC) of the battery and the operating characteristics of the alkaline electrolyzer being considered the power assignments of the battery and the electrolyzer are determined using the rule-based method. In addition model predictive control (MPC) with good tracking performance is used to adjust the output power of the battery and electrolyzer. Finally the supercapacitor (SC) is controlled to maintain the DC bus voltage while also balancing the system’s power. A simulation was established to verify the feasibility of the designed system. The results show that the electric-hydrogen HESS can stabilize the power fluctuations dynamically when the DDWPGS captures instantaneous power. Moreover its control strategy can not only reduce the start-stop times of the alkaline electrolyzer but also help the energy storage devices to maintain a good state and extend the service life.
Sustainable Propulsion Alternatives in Regional Aviation: The Case of the Canary Islands
May 2023
Publication
Sustainability is one of the main challenges the aviation industry is currently facing. In a global context of energy transition towards cleaner and renewable sources the sector is developing technologies to fly more efficiently and mitigate its environmental impact. Innovative propulsion alternatives such as biofuels electric aircraft and hydrogen engines are already a reality or are close to becoming so. To assess their feasibility a study is conducted on specific routes and aircraft across different flight ranges. The analysis focuses on the Canary Islands an outermost region of the EU with high mobility and no comparable alternative means of transport. For three routes flight profiles are analyzed obtaining the fuel consumption and emissions generated by the conventional propulsion and later applying the sustainable alternatives. The results indicate optimistic perspectives with reductions in environmental impact ranging between 40% and 75% compared to the present.
A Techno-Economic Study for Off-Grid Green Hydrogen Production Plants: The Case of Chile
Jul 2023
Publication
In this study we present a pre-feasibility analysis that examines the viability of implementing autonomous green hydrogen production plants in two strategic regions of Chile. With abundant renewable energy resources and growing interest in decarbonization in Chile this study aims to provide a comprehensive financial analysis from the perspective of project initiators. The assessment includes determining the optimal sizing of an alkaline electrolyzer stack seawater desalination system and solar and wind renewable energy farms and the focus is on conducting a comprehensive financial analysis from the perspective of project initiators to assess project profitability using key economic indicators such as net present value (NPV). The analyses involve determining appropriate sizing of an alkaline electrolyzer stack a seawater desalination system and solar and wind renewable energy farms. Assuming a base case production of 1 kiloton per year of hydrogen the capital expenditures (CAPEX) and operating expenses (OPEX) are determined. Then the manufacturing and production costs per kilogram of green hydrogen are calculated resulting in values of USD 3.53 kg−1 (utilizing wind energy) and USD 5.29 kg−1 (utilizing photovoltaic solar energy). Cash flows are established by adjusting the sale price of hydrogen to achieve a minimum expected return on investment of 4% per year yielding minimum prices of USD 7.84 kg−1 (with wind energy) and USD 11.10 kg−1 (with photovoltaic solar energy). Additionally a sensitivity analysis is conducted to assess the impact of variations in investment and operational costs. This research provides valuable insights into the financial feasibility of green hydrogen production in Chile contributing to understanding renewable energy-based hydrogen projects and their potential economic benefits. These results can provide a reference for future investment decisions and the global development of green hydrogen production plants.
Green Energy by Hydrogen Production from Water Splitting, Water Oxidation Catalysis and Acceptorless Dehydrogenative Coupling
Feb 2023
Publication
In this review we want to explain how the burning of fossil fuels is pushing us towards green energy. Actually for a long time we have believed that everything is profitable that resources are unlimited and there are no consequences. However the reality is often disappointing. The use of non-renewable resources the excessive waste production and the abandonment of the task of recycling has created a fragile thread that once broken may never restore itself. Metaphors aside we are talking about our planet the Earth and its unique ability to host life including ourselves. Our world has its balance; when the wind erodes a mountain a beach appears or when a fire devastates an area eventually new life emerges from the ashes. However humans have been distorting this balance for decades. Our evolving way of living has increased the number of resources that each person consumes whether food shelter or energy; we have overworked everything to exhaustion. Scientists worldwide have already said actively and passively that we are facing one of the biggest problems ever: climate change. This is unsustainable and we must try to revert it or if we are too late slow it down as much as possible. To make this happen there are many possible methods. In this review we investigate catalysts for using water as an energy source or instead of water alcohols. On the other hand the recycling of gases such as CO2 and N2O is also addressed but we also observe non-catalytic means of generating energy through solar cell production.
Modeling Green Hydrogen Production Using Power-to-x: Saudi and German Contexts
Apr 2024
Publication
This study assesses the competitiveness of producing green hydrogen (H2) in Saudi Arabia and Germany using a power-to-carrier (P2X) model in PLEXOS for 2030 and beyond. The target amount of H2 to be produced serves as the only exogenous input allowing the model which runs on an hourly temporal resolution to endogenously optimize the electrolyzer technology (alkaline proton exchange membrane or solid oxide electrolyzer cell) the capacity of the electrolyzer to be built and the optimal carbon-free energy mix. Results suggest the overall investment needs in Saudi Arabia are approximately 25% lower than those for wind-based hydrogen production in Germany with the best-case scenario to produce 0.213 Mt of green H2 costing a net present value of $6.20 billion in Saudi Arabia compared to $8.11 billion in Germany. The findings indicate that alkaline electrolyzers dominate the production process favored for their low cost despite the higher efficiencies of other electrolyzer types. Moreover the model opts to dump excess energy rather than construct battery storage. Based on 16 scenarios the study determines a levelized cost of hydrogen of 2.34–3.08 $/kg for Saudi Arabia compared with 3.06–3.69 $/kg in Germany. Subsequently a detailed sensitivity analysis considers various discount rates for both countries. It is concluded that even when considering shipment costs from Saudi Arabia to Germany (~1 $/kg) green H2 can still be competitively delivered from Saudi Arabia to Germany.
Optimal Pathways for the Decarbonisation of the Transport Sector: Trade-offs Between Battery and Hydrogen Technologies Using a Whole Energy System Perspective
Jun 2023
Publication
Several countries have revised their targets in recent years to reach net-zero CO2 emissions across all sectors by 2050 and the transport sector is responsible for a significant share of these emissions. This study compares possible pathways to decarbonise the transport sector through electrification including passenger cars light commercial vehicles and heavy commercial vehicles. To do so we explore 125 scenarios by varying the share of battery and hydrogen-based fuel cell electric vehicles in each of the three categories above independently. We further model the decarbonisation of the industrial hydrogen demand using electrolysers with hydrogen storage. To explore the potential role of electric and hydrogen transport as well as their trade-offs we use GRIMSEL an open-source sector coupling energy system model of Switzerland which includes the residential commercial industrial and transport sectors with four energy carriers namely electricity heat hot water and hydrogen. The total costs are minimised from a social planner perspective. We find that the full electrification of the transport sector could lead on average to a 12% increase in costs by 2050 and 1.3 MtCO2/year which represents a 90% CO2 emissions reduction for the whole sector. Second the transport energy self-sufficiency (i.e. the share of domestic electricity generation in final transport demand) may reach up to 50% for the scenarios with the largest share of battery electric vehicles mainly due to a smaller energy demand than with hydrogen vehicles. Third more than three quarters of the industrial hydrogen production is met by local photovoltaic electricity coupled with battery at minimum costs i.e. green hydrogen. Finally the use of hydrogen as an energy carrier to store electricity over a long period is not cost-optimal.
What Can Accelerate Technological Convergence of Hydrogen Energy: A Regional Perspective
Jun 2023
Publication
Focusing on technological innovation and convergence is crucial for utilizing hydrogen energy an emerging infrastructure area. This research paper analyzes the extent of technological capabilities in a region that could accelerate the occurrence of technological convergence in the fields related to hydrogen energy through the use of triadic patents their citation information and their regional information. The results of the Bayesian spatial model indicate that the active exchange of diverse original technologies could facilitate technological convergence in the region. On the other hand it is difficult to achieve regional convergence with regard to radical technology. The findings could shed light on the establishment of an R&D strategy for hydrogen technologies. This study could contribute to the dissemination and utilization of hydrogen technologies for sustainable industrial development.
Feasibility Study on the Provision of Electricity and Hydrogen for Domestic Purposes in the South of Iran using Grid-connected Renewable Energy Plants
Dec 2018
Publication
This work presents a feasibility study on the provision of electricity and hydrogen with renewable grid connected and off-the-grid systems for Bandar Abbas City in the south of Iran. The software HOMER Pro® has been used to perform the analysis. A techno-enviro-economic study comparing a hybrid system consisting of the grid/wind turbine and solar cell is done. The wind turbine is analyzed using four types of commercially available vertical axis wind turbines (VAWTs). According to the literature review no similar study has been performed so far on the feasibility of using VAWTs and also no work exists on the use of a hybrid system in the studied area. The results indicated that the lowest price of providing the required hydrogen was $0.496 which was achieved using the main grid. Also the lowest price of the electricity generated was $1.55 which was obtained through using EOLO VAWT in the main grid/wind turbine/solar cell scenario. Also the results suggested that the highest rate of preventing CO2 emission which was also the lowest rate of using the national grid with 3484 kg/year was associated with EOLO wind turbines where only 4% of the required electricity was generated by the national grid.
Energy Assessment of an Integrated Hydrogen Production System
Dec 2022
Publication
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.
The Cost Reduction Analysis of Green Hydrogen Production from Coal Mine Underground Water for Circular Economy
May 2024
Publication
The novelty of the paper is the analysis of the possibilities of reducing the operating costs of a mine water pumping station in an abandoned coal mine. To meet the energy needs of the pumping station and reduce the carbon footprint “green” energy from a photovoltaic farm was used. Surplus green energy generated during peak production is stored in the form of green hydrogen from the water electrolysis process. Rainwater and process water are still underutilized sources for increasing water resources and reducing water stress in the European Union. The article presents the possibilities of using these waters after purification in the production of green hydrogen by electrolysis. The article also presents three variants that ensure the energy self-sufficiency of the proposed concepts of operation of the pumping station.
OIES Podcast - Renewable Hydrogen Import Routes into the EU
Jun 2023
Publication
In this podcast David Ledesma talks to Martin Lambert and Abdurahman Alsulaiman about the potential hydrogen import market particularly focusing on the EU which currently holds the largest and earliest hydrogen target. The podcast explores the emerging hydrogen trade market and considers numerous possibilities for its open up providing better clarity on policy statements and balance them against project announcements.
Throughout the podcast Martin and Abdulrahman delve into various key points – they shed light on the primary areas of focus for projects set to be completed by or before 2030 as well as the distinction between announcements and tangible progress such as projects currently at the Final Investment Decision stage or under construction.
Additionally they explore the EU’s role as one of the few countries to have publicly announced its requirements for hydrogen imports and its ambitious hydrogen import target. The EU is currently establishing a benchmark for the future hydrogen market. However in order for the EU to succeed in establishing future hydrogen supply lines with future trade partners it will be crucial to engage in open dialogues covering a wide range of topics.
Join us in this podcast as we uncover the potential of the hydrogen import market with a specific focus on the EU and discuss the necessary steps for its success.
The podcast can be found on their website.
Throughout the podcast Martin and Abdulrahman delve into various key points – they shed light on the primary areas of focus for projects set to be completed by or before 2030 as well as the distinction between announcements and tangible progress such as projects currently at the Final Investment Decision stage or under construction.
Additionally they explore the EU’s role as one of the few countries to have publicly announced its requirements for hydrogen imports and its ambitious hydrogen import target. The EU is currently establishing a benchmark for the future hydrogen market. However in order for the EU to succeed in establishing future hydrogen supply lines with future trade partners it will be crucial to engage in open dialogues covering a wide range of topics.
Join us in this podcast as we uncover the potential of the hydrogen import market with a specific focus on the EU and discuss the necessary steps for its success.
The podcast can be found on their website.
Assessing the Role of Hydrogen in Sustainable Energy Futures: A Comprehensive Bibliometric Analysis of Research and International Collaborations in Energy and Environmental Engineering
Apr 2024
Publication
The main results highlighted in this article underline the critical significance of hydrogen technologies in the move towards carbon neutrality. This research focuses on several key areas including the production storage safety and usage of hydrogen alongside innovative approaches for assessing hydrogen purity and production-related technologies. This study emphasizes the vital role of hydrogen storage technology for the future utilization of hydrogen as an energy carrier and the advancement of technologies that facilitate effective safe and cost-efficient hydrogen storage. Furthermore bibliometric analysis has been instrumental in identifying primary research fields such as hydrogen storage hydrogen production efficient electrocatalysts rotary engines utilizing hydrogen as fuel and underground hydrogen storage. Each domain is essential for realizing a sustainable hydrogen economy reflecting the significant research and development efforts in hydrogen technologies. Recent trends have shown an increased interest in underground hydrogen storage as a method to enhance energy security and assist in the transition towards sustainable energy systems. This research delves into the technical economic and environmental facets of employing geological formations for large-scale seasonal and long-term hydrogen storage. Ultimately the development of hydrogen technologies is deemed crucial for meeting sustainable development goals particularly in terms of addressing climate change and reducing greenhouse gas emissions. Hydrogen serves as an energy carrier that could substantially lessen reliance on fossil fuels while encouraging the adoption of renewable energy sources aiding in the decarbonization of transport industry and energy production sectors. This in turn supports worldwide efforts to curb global warming and achieve carbon neutrality.
Hydrogen Storage by Liquid Hydrogen Carriers: Catalyst, Renewable Carrier, and Technology - A Review
Mar 2023
Publication
Hydrogen has attracted widespread attention as a carbon-neutral energy source but developing efficient and safe hydrogen storage technologies remains a huge challenge. Recently liquid organic hydrogen carriers (LOHCs) technology has shown great potential for efficient and stable hydrogen storage and transport. This technology allows for safe and economical large-scale transoceanic transportation and long-cycle hydrogen storage. In particular traditional organic hydrogen storage liquids are derived from nonrenewable fossil fuels through costly refining procedures resulting in unavoidable environmental contamination. Biomass holds great promise for the preparation of LOHCs due to its unique carbon-balance properties and feasibility to manufacture aromatic and nitrogen-doped compounds. According to recent studies almost 100% conversion and 92% yield of benzene could be obtained through advanced biomass conversion technologies showing great potential in preparing biomass-based LOHCs. Overall the present LOHCs systems and their unique applications are introduced in this review and the technical paths are summarized. Furthermore this paper provides an outlook on the future development of LOHCs technology focusing on biomass-derived aromatic and N-doped compounds and their applications in hydrogen storage.
Wind Farm Control for Improved Battery Lifetime in Green Hydrogen Systems without a Grid Connection
Jul 2023
Publication
Green hydrogen is likely to play an important role in meeting the net-zero targets of countries around the globe. One potential option for green hydrogen production is to run electrolysers directly from offshore wind turbines with no grid connection and hence no expensive cabling to shore. In this work an innovative proof of concept of a wind farm control methodology designed to reduce variability in wind farm active power output is presented. Smoothing the power supplied by the wind farm to the battery reduces the size and number of battery charge cycles and helps to increase battery lifetime. This work quantifies the impact of the wind farm control method on battery lifetime for wind farms of 1 4 9 and 16 wind turbines using suitable wind farm battery and electrolyser models. The work presented shows that wind farm control for smoothing wind farm power output could play a critical role in reducing the levelised cost of green hydrogen produced from wind farms with no grid connection by reducing the damaging load cycles on batteries in the system. Hence this work paves the way for the design and testing of a full implementation of the wind farm controller.
How to Make Climate-neutral Aviation Fly
Jul 2023
Publication
The European aviation sector must substantially reduce climate impacts to reach net-zero goals. This reduction however must not be limited to flight CO2 emissions since such a narrow focus leaves up to 80% of climate impacts unaccounted for. Based on rigorous life-cycle assessment and a time-dependent quantification of non-CO2 climate impacts here we show that from a technological standpoint using electricity-based synthetic jet fuels and compensating climate impacts via direct air carbon capture and storage (DACCS) can enable climate-neutral aviation. However with a continuous increase in air traffic synthetic jet fuel produced with electricity from renewables would exert excessive pressure on economic and natural resources. Alternatively compensating climate impacts of fossil jet fuel via DACCS would require massive CO2 storage volumes and prolong dependence on fossil fuels. Here we demonstrate that a European climate-neutral aviation will fly if air traffic is reduced to limit the scale of the climate impacts to mitigate.
Hydrogen Carriers: Scientific Limits and Challenges for the Supply Chain, and Key Factors for Techno-Economic Analysis
Aug 2023
Publication
Hydrogen carriers are one of the keys to the success of using hydrogen as an energy vector. Indeed sustainable hydrogen production exploits the excess of renewable energy sources after which temporary storage is required. The conventional approaches to hydrogen storage and transport are compressed hydrogen (CH2 ) and liquefied hydrogen (LH2 ) which require severe operating conditions related to pressure (300–700 bar) and temperature (T < −252 ◦C) respectively. To overcome these issues which have hindered market penetration several alternatives have been proposed in the last few decades. In this review the most promising hydrogen carriers (ammonia methanol liquid organic hydrogen carriers and metal hydrides) have been considered and the main stages of their supply chain (production storage transportation H2 release and their recyclability) have been described and critically analyzed focusing on the latest results available in the literature the highlighting of which is our current concern. The last section reviews recent techno-economic analyses to drive the selection of hydrogen carrier systems and the main constraints that must be considered. The analyzed results show how the selection of H2 carriers is a multiparametric function and it depends on technological factors as well as international policies and regulations.
Modeling the Global Annual Carbon Footprint for the Transportation Sector and a Path to Sustainability
Jun 2023
Publication
The transportation industry’s transition to carbon neutrality is essential for addressing sustainability concerns. This study details a model for calculating the carbon footprint of the transportation sector as it progresses towards carbon neutrality. The model aims to support policymakers in estimating the potential impact of various decisions regarding transportation technology and infrastructure. It accounts for energy demand technological advancements and infrastructure upgrades as they relate to each transportation market: passenger vehicles commercial vehicles aircraft watercraft and trains. A technology roadmap underlies this model outlining anticipated advancements in batteries hydrogen storage biofuels renewable grid electricity and carbon capture and sequestration. By estimating the demand and the technologies that comprise each transportation market the model estimates carbon emissions. Results indicate that based on the technology roadmap carbon neutrality can be achieved by 2070 for the transportation sector. Furthermore the model found that carbon neutrality can still be achieved with slippage in the technology development schedule; however delays in infrastructure updates will delay carbon neutrality while resulting in a substantial increase in the cumulative carbon footprint of the transportation sector.
Exploring Key Operational Factors for Improving Hydrogen Production in a Pilot-scale Microbial Electrolysis Cell Treating Urban Wastewater
Jun 2023
Publication
Bioelectrochemical systems (BES) are becoming popular technologies with a plethora of applications in the environmental field. However research on the scale-up of these systems is scarce. To understand the limiting factors of hydrogen production in microbial electrolysis cell (MEC) at pilot scale a 135 L MEC was operated for six months under a wide range of operational conditions: applied potential [0.8-1.1 V] hydraulic residence time [1.1-3.9 d] and temperature [18-30 ºC] using three types of wastewater; synthetic (900 mg CODs L-1) raw urban wastewater (200 mg CODs L-1) and urban wastewater amended with acetate (1000 mg CODs L-1). The synthetic wastewater yielded the maximum current density (1.23 A m-2) and hydrogen production (0.1 m3 m-3 d-1) ever reported in a pilot scale MEC with a cathodic recovery of 70% and a coulombic efficiency of 27%. In contrast the use of low COD urban wastewater limited the plant performance. Interestingly it was possible to improve hydrogen production by reducing the hydraulic residence time finding the optimal applied potential or increasing the temperature. Further the pilot plant demonstrated a robust capacity to remove the organic matter present in the wastewater under different conditions with removal efficiencies above 70%. This study shows improved results compared to similar MEC pilot plants treating domestic wastewater in terms of hydrogen production and treatment efficiency and also compares its performance against conventional activated sludge processes.
Recent Advances in Sustainable and Safe Marine Engine Operation with Alternative Fuels
Nov 2022
Publication
Pursuing net-zero emission operations in the shipping industry are quintessential for this sector to mitigate the environmental impact caused by hydrocarbon fuel combustion. Significant contributions to this are expected from the substitution of conventional marine fuels by alternative emission-free fuels with lower emission footprints. This study aims to conduct a comprehensive literature review for delineating the main characteristics of the considered alternative fuels specifically focusing on hydrogen methanol and ammonia which have recently attracted attention from both industry and academia. This study comparatively assesses the potential of using these fuels in marine engines and their subsequent performance characteristics as well as the associated environmental benefits. In addition the required storage conditions space as well as the associated costs are reviewed. Special attention is given to the safety characteristics and requirements for each alternative fuel. The results of this study demonstrate that the environmental benefits gained from alternative fuel use are pronounced only when renewable energy is considerably exploited for their production whereas the feasibility of each fuel depends on the vessel type used and pertinent storage constraints. Hydrogen ammonia and methanol are considered best-fit solutions for small scale shipping requiring minimal on-board storage. In addition the need for comparative assessments between diesel and alternative fuels is highlighted and sheds light on marine engines’ operational characteristics. Moreover using combinations of alternative and diesel fuels is identified as a direction towards decarbonisation of the maritime sector; intensifying the need for optimisation studies on marine engine design and operation. This study concludes with recommendations for future research directions thus contributing to fuel research concepts that can facilitate the shipboard use of alternative fuels.
Enhancing Energy Transition through Sector Coupling: A Review of Technologies and Models
Jul 2023
Publication
In order to effectively combat the effects of global warming all sectors must actively reduce greenhouse gas emissions in a sustainable and substantial manner. Sector coupling has emerged as a critical technology that can integrate energy systems and address the temporal imbalances created by intermittent renewable energy sources. Despite its potential current sector coupling capabilities remain underutilized and energy modeling approaches face challenges in understanding the intricacies of sector coupling and in selecting appropriate modeling tools. This paper presents a comprehensive review of sector coupling technologies and their role in the energy transition with a specific focus on the integration of electricity heat/cooling and transportation as well as the importance of hydrogen in sector coupling. Additionally we conducted an analysis of 27 sector coupling models based on renewable energy sources with the goal of aiding deciders in identifying the most appropriate model for their specific modeling needs. Finally the paper highlights the importance of sector coupling in achieving climate protection goals while emphasizing the need for technological openness and market-driven conditions to ensure economically efficient implementation.
Recent Advances in Power-to-X Technology for the Production of Fuels and Chemicals
Jun 2019
Publication
Environmental issues related to greenhouse gas emissions are progressively pushing the transition toward fossil-free energy scenario in which renewable energies such as solar and wind power will unavoidably play a key role. However for this transition to succeed significant issues related to renewable energy storage have to be addressed. Power-to-X (PtX) technologies have gained increased attention since they actually convert renewable electricity to chemicals and fuels that can be more easily stored and transported. H2 production through water electrolysis is a promising approach since it leads to the production of a sustainable fuel that can be used directly in hydrogen fuel cells or to reduce carbon dioxide (CO2) in chemicals and fuels compatible with the existing infrastructure for production and transportation. CO2 electrochemical reduction is also an interesting approach allowing the direct conversion of CO2 into value-added products using renewable electricity. In this review attention will be given to technologies for sustainable H2 production focusing on water electrolysis using renewable energy as well as on its remaining challenges for large scale production and integration with other technologies. Furthermore recent advances on PtX technologies for the production of key chemicals (formic acid formaldehyde methanol and methane) and fuels (gasoline diesel and jet fuel) will also be discussed with focus on two main pathways: CO2 hydrogenation and CO2 electrochemical reduction.
Hydrogen Production by Methane Pyrolysis in Molten Binary Copper Alloys
Sep 2023
Publication
The utilization of hydrogen as an energy carrier and reduction agent in important industrial sectors is considered a key parameter on the way to a sustainable future. Steam reforming of methane is currently the most industrially used process to produce hydrogen. One major drawback of this method is the simultaneous generation of carbon dioxide. Methane pyrolysis represents a viable alternative as the basic reaction produces no CO2 but solid carbon besides hydrogen. The aim of this study is the investigation of different molten copper alloys regarding their efficiency as catalytic media for the pyrolysis of methane in an inductively heated bubble column reactor. The conducted experiments demonstrate a strong influence of the catalyst in use on the one hand on the conversion rate of methane and on the other hand on the properties of the produced carbon. Optimization of these parameters is of crucial importance to achieve the economic competitiveness of the process.
Science and Technology of Ammonia Combustion
Nov 2018
Publication
This paper focuses on the potential use of ammonia as a carbon-free fuel and covers recent advances in the development of ammonia combustion technology and its underlying chemistry. Fulfilling the COP21 Paris Agreement requires the de-carbonization of energy generation through utilization of carbon-neutral and overall carbon-free fuels produced from renewable sources. Hydrogen is one of such fuels which is a potential energy carrier for reducing greenhouse-gas emissions. However its shipment for long distances and storage for long times present challenges. Ammonia on the other hand comprises 17.8% of hydrogen by mass and can be produced from renewable hydrogen and nitrogen separated from air. Furthermore thermal properties of ammonia are similar to those of propane in terms of boiling temperature and condensation pressure making it attractive as a hydrogen and energy carrier. Ammonia has been produced and utilized for the past 100 years as a fertilizer chemical raw material and refrigerant. Ammonia can be used as a fuel but there are several challenges in ammonia combustion such as low flammability high NOx emission and low radiation intensity. Overcoming these challenges requires further research into ammonia flame dynamics and chemistry. This paper discusses recent successful applications of ammonia fuel in gas turbines co-fired with pulverize coal and in industrial furnaces. These applications have been implemented under the Japanese ‘Cross-ministerial Strategic Innovation Promotion Program (SIP): Energy Carriers’. In addition fundamental aspects of ammonia combustion are discussed including characteristics of laminar premixed flames counterflow twin-flames and turbulent premixed flames stabilized by a nozzle burner at high pressure. Furthermore this paper discusses details of the chemistry of ammonia combustion related to NOx production processes for reducing NOx and validation of several ammonia oxidation kinetics models. Finally LES results for a gas-turbine-like swirl-burner are presented for the purpose of developing low-NOx single-fuelled ammonia gas turbine combustors.
Gauging Public Perceptions of Blue and Green Hydrogen Futures: Is the Twin-track Approach Compatible with Hydrogen Acceptance?
Jun 2023
Publication
National hydrogen strategies are emerging as a critical pillar of climate change policy. For homes connected to the gas grid hydrogen may offer an alternative decarbonisation pathway to electrification. Hydrogen production pathways in countries such as the UK will involve both the gas network and the electricity grid with related policy choices and investment decisions impacting the potential configuration of consumer acceptance for hydrogen homes. Despite the risk of public resistance be it on environmental economic or social grounds few studies have explored the emerging contours of domestic hydrogen acceptance. To date there is scarce evidence on public perceptions of national hydrogen policy and the extent to which attitudes may be rooted in prior knowledge and awareness or open to change following information provision and engagement. In response this study evaluates consumer preferences for a low-carbon energy future wherein parts of the UK housing stock may adopt low-carbon hydrogen boilers and hobs. Drawing on data from online focus groups we examine consumer perceptions of the government's twin-track approach which envisions important roles for both ‘blue’ and ‘green’ hydrogen to meet net zero ambitions. Through a mixed-methods multigroup analysis the underlying motivation is to explore whether the twin-track approach appears compatible with hydrogen acceptance. Moving forward hydrogen policy should ensure greater transparency concerning the benefits costs and risks of the transition with clearer communication about the justification for supporting respective hydrogen production pathways.
Investment Timing Analysis of Hydrogen-Refueling Stations and the Case of China: Independent or Co-Operative Investment?
Jun 2023
Publication
The investment in hydrogen-refueling stations (HRS) is key to the development of a hydrogen economy. This paper focuses on the decision-making for potential investors faced with the thought-provoking question of when the optimal timing to invest in HRS is. To fill the gap that exists due to the fact that few studies explain why HRS investment timing is critical we expound that earlier investment in HRS could induce the first mover advantages of the technology diffusion theory. Additionally differently from the previous research that only considered that HRS investment is just made by one individual firm we innovatively examine the HRS co-investment made by two different firms. Accordingly we compare these two optional investment modes and determine which is better considering either independent investment or co-operative investment. We then explore how the optimal HRS investment timing could be figured out under conditions of uncertainty with the real options approach. Given the Chinese HRS case under the condition of demand uncertainty the hydrogen demand required for triggering investment is viewed as the proxy for investment timing. Based on analytical and numerical results we conclude that one-firm independent investment is better than two-firm cooperative investment to develop HRS not only in terms of the earlier investment timing but also in terms of the attribute for dealing with the uncertainty. Finally we offer recommendations including stabilizing the hydrogen demand for decreasing uncertainty and accelerating firms’ innovation from both technological and strategic perspectives in order to ensure firms can make HRS investments on their own.
Techno-Economic Analysis of Solid Oxide Fuel Cell-Gas Turbine Hybrid Systems for Stationary Power Applications Using Renewable Hydrogen
Jun 2023
Publication
Solid oxide fuel cell (SOFC)–gas turbine (GT) hybrid systems can produce power at high electrical efficiencies while emitting virtually zero criteria pollutants (e.g. ozone carbon monoxide oxides of nitrogen and sulfur and particulate matters). This study presents new insights into renewable hydrogen (RH2 )-powered SOFC–GT hybrid systems with respect to their system configuration and techno-economic analysis motivated by the need for clean on-demand power. First three system configurations are thermodynamically assessed: (I) a reference case with no SOFC off-gas recirculation (II) a case with cathode off-gas recirculation and (III) a case with anode off-gas recirculation. While these configurations have been studied in isolation here we provide a detailed performance comparison. Moreover a techno-economic analysis is conducted to study the economic competitiveness of RH2 -fueled hybrid systems and the economies of scale by offering a comparison to natural gas (NG)-fueled systems. Results show that the case with anode off-gas recirculation with 68.50%-lower heating value (LHV) at a 10 MW scale has the highest efficiency among the studied scenarios. When moving from 10 MW to 50 MW the efficiency increases to 70.22%-LHV. These high efficiency values make SOFC–GT hybrid systems highly attractive in the context of a circular economy as they outcompete most other power generation technologies. The cost-of-electricity (COE) is reduced by about 10% when moving from 10 MW to 50 MW from USD 1976/kW to USD 1668/kW respectively. Renewable H2 is expected to be economically competitive with NG by 2030 when the U.S. Department of Energy’s target of USD 1/kg RH2 is reached.
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