Applications & Pathways

Green ammonia has potential as a zero-emissions energy vector in applications such as energy storage transmission and distribution and zero-emissions transportation. Renewable energy such as offshore wind energy has been proposed to power its production. This paper designed and analyzed an on-land small-scale power-to-ammonia (P2A) production system with a target nominal output of 15 tonnes of ammonia per day which will use an 8 MW offshore turbine system off the coast of Nova Scotia Canada as the main power source. The P2A system consists of a reverse osmosis system a proton exchange membrane (PEM) electrolyser a hydrogen storage tank a nitrogen generator a set of compressors and heat exchangers an autothermal Haber-Bosch reactor and an ammonia storage tank. The system uses an electrical grid as a back-up for when the wind energy is insufficient as the process assumes a steady state. Two scenarios were analyzed with Scenario 1 producing a steady state of 15 tonnes of ammonia per day and Scenario 2 being one that switched production rates whenever wind speeds were low to 55% the nominal capacity. The results show that the grid connected P2A system has significant emissions for both scenarios which is larger than the traditional fossil-fuel based ammonia production when using the grid in provinces like Nova Scotia even if it is just a back-up during low wind power generation. The levelized cost of ammonia (LCOA) was calculated to be at least 2323 CAD tonne−1 for both scenarios which is not cost competitive in this small production scale. Scaling up the whole system reducing the reliance on the electricity grid increasing service life and decreasing windfarm costs could reduce the LCOA and make this P2A process more cost competitive.

Fuel cell technologies have several applications in stationary power production such as units for primary power generation grid stabilization systems adopted to generate backup power and combined-heat-and-power configurations (CHP). The main sectors where stationary fuel cells have been employed are (a) micro-CHP (b) large stationary applications (c) UPS and IPS. The fuel cell size for stationary applications is strongly related to the power needed from the load. Since this sector ranges from simple backup systems to large facilities the stationary fuel cell market includes few kWs and less (micro-generation) to larger sizes of MWs. The design parameters for the stationary fuel cell system differ for fuel cell technology (PEM AFC PAFC MCFC and SOFC) as well as the fuel type and supply. This paper aims to present a comprehensive review of two main trends of research on fuel-cell-based poly-generation systems: tracking the market trends and performance analysis. In deeper detail the present review will list a potential breakdown of the current costs of PEM/SOFC production for building applications over a range of production scales and at representative specifications as well as broken down by component/material. Inherent to the technical performance a concise estimation of FC system durability efficiency production maintenance and capital cost will be presented.

Hydrogen Fuelling Infrastructure Research and Station Technology (H2FIRST) is a project initiated by the DOE in 2015 and executed by Sandia National Laboratories and the National Renewable Energy Laboratory to address R&D barriers to the deployment of hydrogen fuelling infrastructure. One key barrier to the deployment of fuelling stations is the land area they require (i.e. ""footprint""). Space is particularly a constraint in dense urban areas where hydrogen demand is high but space for fuelling stations is limited. This work presents current fire code requirements that inform station footprint then identifies and quantifies opportunities to reduce footprint without altering the safety profile of fuelling stations. Opportunities analyzed include potential new methods of hydrogen delivery as well as alternative placements of station technologies (i.e. rooftop/underground fuel storage). As interest in heavy-duty fuelling stations and other markets for hydrogen grows this study can inform techniques to reduce the footprint of heavy-duty stations as well.



This work characterizes generic designs for stations with a capacity of 600 kg/day hydrogen dispensed and 4 dispenser hoses. Three base case designs (delivered gas delivered liquid and on-site electrolysis production) have been modified in 5 different ways to study the impacts of recently released fire code changes colocation with gasoline refuelling alternate delivery assumptions underground storage of hydrogen and rooftop storage of hydrogen resulting in a total of 32 different station designs. The footprints of the base case stations range from 13000 to 21000 ft².



A significant focus of this study is the NFPA 2 requirements especially the prescribed setback distances for bulk gaseous or liquid hydrogen storage. While the prescribed distances are large in some cases these setback distances are found to have a nuanced impact on station lot size; considerations of the delivery truck path traffic flow parking and convenience store location are also important. Station designs that utilize underground and rooftop storage can reduce footprint but may not be practical or economical. For example burying hydrogen storage tanks underground can reduce footprint but the cost savings they enable depend on the cost of burial and the cost land. Siting and economic analysis of station lot sizes illustrate the benefit of smaller station footprints in the flexibility and cost savings they can provide. This study can be used as a reference that provides examples of the key design differences that fuelling stations can incorporate the approximate sizes of generic station lots and considerations that might be unique to particular designs.

European countries approach the market ramp-up of hydrogen very differently. In some cases the economic and political starting points differ significantly. While the probability is high that some countries such as Germany or Italy will import hydrogen in the long term other countries such as United Kingdom France or Spain could become hydrogen exporters. The reasons for this are the higher potential for renewable energies but also a technology-neutral approach on the supply side.

This report fulfils Deliverable Five for Research Project 2.1-01 of the Future Fuels CRC. The aims of this project Crystallising lessons learned from major infrastructure upgrades are to provide a report on lessons learned from earlier infrastructure upgrades and fuel transitions and identify tools that can be used to develop consistent messaging around the proposed transition to hydrogen and/or other low-carbon fuels. In both the report and the toolkit there are recommendations on how to apply lessons learned and shape messaging throughout the value chain based on prior infrastructure upgrades.



This report presents three Australian case studies that that are relevant to the development of future fuels: the transition from town gas to natural gas the use of ethanol and LPG as motor fuels and the development of coal seam gas resources. Drawing on published information each case study provides an account of the issues that arose during the upgrade or transition and of the approaches through which industry and government stakeholders managed these issues. From these accounts lessons are identified that can guide stakeholder engagement in future infrastructure upgrades and fuel transitions. The findings from the case studies and academic literature have been used to develop an accompanying draft toolkit for use by FFCRC stakeholders.



The report also distils applicable lessons and frameworks from academic literature about stakeholder analysis megaprojects and the social acceptance of industries and technologies. This report is meant to be used in conjunction with a companion toolkit that provides a framework for making coordinated decisions across the fuel value chain.



You can read the full report on the Future Fuels CRC website here

The paper presents a sustainable electric powertrain for a transit city bus featuring an electrochemical battery-free power unit consisting of a hydrogen fuel cell stack and a kinetic energy storage system based on high-speed flywheels. A rare-earth free high-efficiency motor technology is adopted to pursue a more sustainable vehicle architecture by limiting the use of critical raw materials. A suitable dynamic energetic model of the full vehicle powertrain has been developed to investigate the feasibility of the traction system and the related energy management control strategy. The model includes losses characterisation as a function of the load of the main components of the powertrain by using experimental tests and literature data. The performance of the proposed solution is evaluated by simulating a vehicle mission on an urban path in real traffic conditions. Considerations about the effectiveness of the traction system are discussed.

Recent environmental and climate change issues make it imperative to persistently approach research into the development of technologies designed to ensure the sustainability of global mobility. At the European Union level the transport sector is responsible for approximately 28% of greenhouse gas emissions and 84% of them are associated with road transport. One of the most effective ways to enhance the de-carbonization process of the transport sector is through the promotion of electric propulsion which involves overcoming barriers related to reduced driving autonomy and the long time required to recharge the batteries. This paper develops and implements a method meant to increase the autonomy and reduce the battery charging time of an electric car to comparable levels of an internal combustion engine vehicle. By doing so the cost of such vehicles is the only remaining significant barrier in the way of a mass spread of electric propulsion. The chosen method is to hybridize the electric powertrain by using an additional source of fuel; hydrogen gas stored in pressurized cylinders is converted in situ into electrical energy by means of a proton exchange membrane fuel cell. The power generated on board can then be used under the command of a dedicated management system for battery charging leading to an increase in the vehicle’s autonomy. Modeling and simulation results served to easily adjust the size of the fuel cell hybrid electric powertrain. After optimization an actual fuel cell was built and implemented on a vehicle that used the body of a Jeep Wrangler from which the thermal engine associated subassemblies and gearbox were removed. Once completed the vehicle was tested in traffic conditions and its functional performance was established.

Hydrogen and its energy carriers such as liquid hydrogen (LH2) methylcyclohexane (MCH) and ammonia (NH3) are essential components of low-carbon energy systems. To utilize hydrogen energy the complete environmental merits of its supply chain should be evaluated. To understand the expected environmental benefit under the uncertainty of hydrogen technology development we conducted life-cycle inventory analysis and calculated CO2 emissions and their uncertainties attributed to the entire supply chain of hydrogen and NH3 power generation (co-firing and mono-firing) in Japan. Hydrogen was assumed to be produced from overseas renewable energy sources with LH2/MCH as the carrier and NH3 from natural gas or renewable energy sources. The Japanese life-cycle inventory database was used to calculate emissions. Monte Carlo simulations were performed to evaluate emission uncertainty and mitigation factors using hydrogen energy. For LH2 CO2 emission uncertainty during hydrogen liquefaction can be reduced by using low-carbon fuel. For MCH CO2 emissions were not significantly affected by power consumption of overseas processes; however it can be reduced by implementing low-carbon fuel and waste-heat utilization during MCH dehydrogenation. Low-carbon NH3 production processes significantly affected power generation whereas carbon capture and storage during NH3 production showed the greatest reduction in CO2 emission. In conclusion reducing CO2 emissions during the production of hydrogen and NH3 is key to realize low-carbon hydrogen energy systems.

The U.S. energy system is evolving as society and technologies change. Renewable electricity generation—especially from wind and solar—is growing rapidly and alternative energy sources are being developed and implemented across the residential commercial transportation and industrial sectors to take advantage of their cost security and health benefits. Systemic changes present numerous challenges to grid resiliency and energy affordability creating a need for synergistic solutions that satisfy multiple applications while yielding system-wide cost and emissions benefits. One such solution is an integrated hydrogen energy system (Figure ES-1). This is the focus of H₂@Scale—a U.S. Department of Energy (DOE) initiative led by the Office of Energy Efficiency and Renewable Energy’s Hydrogen and Fuel Technologies Office. H₂@Scale brings together stakeholders to advance affordable hydrogen production transport storage and utilization in multiple energy sectors. The H₂@Scale concept involves hydrogen as an energy intermediate. Hydrogen can be produced from various conventional and renewable energy sources including as a responsive load on the electric grid. Hydrogen has many current applications and many more potential applications such as energy for transportation—used directly in fuel cell electric vehicles (FCEVs) as a feedstock for synthetic fuels and to upgrade oil and biomass—feedstock for industry (e.g. for ammonia production metals refining and other end uses) heat for industry and buildings and electricity storage. Owing to its flexibility and fungibility a hydrogen intermediate could link energy sources that have surplus availability to markets that require energy or chemical feedstocks benefiting both. This document builds upon a growing body of analyses of hydrogen as an energy intermediate by reporting the results from our initial analysis of the potential impacts of the H₂@Scale vision by the mid-21st century for the 48 contiguous U.S. states. Previous estimates have been based on expert elicitation and focused on hydrogen demands. We build upon them first by estimating hydrogen’s serviceable consumption potential for possible hydrogen applications and the technical potential for producing hydrogen from various resources. We define the serviceable consumption potential as the quantity of hydrogen that would be consumed to serve the portion of the market that could be captured without considering economics (i.e. if the price of hydrogen were $0/kg over an extended period); thus it can be considered an upper bound for the size of the market. We define the technical potential as the resource potential constrained by real-world geography and system performance but not by economics. We then compare the cumulative serviceable consumption potential with the technical potential of a number of possible sources. Second we estimate economic potential: the quantity of hydrogen at an equilibrium price at which suppliers are willing to sell and consumers are willing to buy the same quantity of hydrogen. We believe this method provides a deeper understanding than was available in the previous analyses. We develop economic potentials for multiple scenarios across various market and technology-advancement assumptions.

This document is the final deliverable of Tasks 2 & 3 of the tender N° FCH / OP / CONTRACT 196: “Development of a Metering Protocol for Hydrogen Refuelling Stations”. In Task 2 a test campaign was organized on several HRS in Europe to apply the testing protocol defined in Task 1. This protocol requires mainly to perform different accuracy tests in order to determine the error of the complete measuring system (i.e. from the mass flow meter to the nozzle) in real fueling conditions. Seven HRS have been selected to fulfill the requirements specified in the tender. Tests results obtained are presented in this deliverable and conclusions are proposed to explain the errors observed. In the frame of Task 3 results and conclusions have been widely presented to additional Metrology Institutes than those involved in Task 1 in order to get their adhesion on the testing proposed protocol. All the work performed in Tasks 2 & 3 and associated outcomes / conclusions are reported here.

Hydrogen as carbon-free fuel is a very promising candidate for climate-neutral internal combustion engine operation. In comparison to other renewable fuels hydrogen does obviously not produce CO2 emissions. In this work two concepts of hydrogen internal combustion engines (H2 -ICEs) are investigated experimentally. One approach is the modification of a state-of-the-art gasoline passenger car engine using hydrogen direct injection. It targets gasoline-like specific power output by mixture enrichment down to stoichiometric operation. Another approach is to use a heavy-duty diesel engine equipped with spark ignition and hydrogen port fuel injection. Here a diesel-like indicated efficiency is targeted through constant lean-burn operation. The measurement results show that both approaches are applicable. For the gasoline engine-based concept stoichio-metric operation requires a three-way catalyst or a three-way NOX storage catalyst as the primary exhaust gas aftertreatment system. For the diesel engine-based concept state-of-the-art selective catalytic reduction (SCR) catalysts can be used to reduce the NOx emissions provided the engine calibration ensures sufficient exhaust gas temperature levels. In conclusion while H2 -ICEs present new challenges for the development of the exhaust gas aftertreatment systems they are capable to realize zero-impact tailpipe emission operation.

The investigation of the various heat management concepts using LH2 requires the development of a modeling environment coupling the cryogenic hydrogen fuel system with turbofan performance. This paper presents a numerical framework to model hydrogen-fueled gas turbine engines with a dedicated heat-management system complemented by an introductory analysis of the impact of using LH2 to precool and intercool in the compression system. The propulsion installations comprise Brayton cycle-based turbofans and first assessments are made on how to use the hydrogen as a heat sink integrated into the compression system. Conceptual tubular compact heat exchanger designs are explored to either precool or intercool the compression system and preheat the fuel to improve the installed performance of the propulsion cycles. The precooler and the intercooler show up to 0.3% improved specific fuel consumption for heat exchanger effectiveness in the range 0.5–0.6 but higher effectiveness designs incur disproportionately higher pressure losses that cancel-out the benefits.

Hydrogen is a bright energy vector that could be crucial to decarbonise and combat climate change. This energy evolution involves several sectors including power backup systems to supply priority facility loads during power outages. As buildings now integrate complex automation domotics and security systems energy backup systems cause interest. A hydrogen-based backup system could supply loads in a multi-day blackout; however the backup system should be sized appropriately to ensure the survival of essential loads and low cost. In this sense this work proposes a sizing of fuel cell (FC) backup systems for low voltage (LV) buildings using the history of power outages. Historical data allows fitting a probability function to determine the appropriate survival of loads. The proposed sizing is applied to a university building with a photovoltaic generation system as a case study. Results show that the sizing of an FC–battery backup system for the installation is 7.6% cheaper than a battery-only system under a usual 330-minutes outage scenario. And 59.3% cheaper in the case of an unusual 48-hours outage scenario. It ensures a 99% probability of supplying essential load during power outages. It evidences the pertinence of an FC backup system to attend to outages of long-duration and the integration of batteries to support the abrupt load variations. This research is highlighted by using historical data from actual outages to define the survival of essential loads with total service probability. It also makes it possible to determine adequate survival for non-priority loads. The proposed sizing is generalisable and scalable for other buildings and allows quantifying the reliability of the backup system tending to the resilience of electrical systems.

Decarbonization of energy economy is nowadays a topical theme and several pathways are under discussion. Gaseous fuels have a fundamental role for this transition and the production of low carbon-impact fuels is necessary to deal with this challenge. The generation of renewable hydrogen is a trusted solution since this energy vector can be promptly produced from electricity and injected into the existing natural gas infrastructure granting storage capacity and easy transportation. This scenario will lead in the near future to hydrogen enrichment of natural gas whose impact on the infrastructures is being actively studied. The effect on end-user devices such as domestic gas boilers instead is still little analyzed and tested but is fundamental to be assessed. The aim of this research is to generate knowledge on the effect of hydrogen enrichment on the widely used premixed boilers: the investigations include pollutant emissions efficiency flashback and explosion hazard control system and materials selection. A model for calculating several parameters related to combustion of hydrogen enriched natural gas is presented. Guidelines for the design of new components are provided and an insight is given on the maximum hydrogen blending bearable by the current boilers.

Hydrogen fuel cell vehicles (FCVs) are regarded as a promising solution to the problems of energy security and environmental pollution. However the technology is under development and the hydrogen consumption is uncertain. The quantitative evaluation of life cycle energy consumption pollution emissions of current and future FCVs in China involves complex processes and parameters. Therefore this study addresses Life Cycle Assessment (LCA) of FCV and focuses on the key parameters of FCV production and different hydrogen production methods which include steam methane reforming catalysis decomposition methanol steam reforming electrolysis–photovoltaic (PV) and electrolysis Chinese electricity grid mix (CN). Sensitivity analysis of bipolar plate glider mass power density fuel cell system efficiency and energy control strategy are performed whilst accounting for different assumption scenarios. The results show that all impact assessment indicators will decrease by 28.8– 44.3% under the 2030 positive scenario for the production of FCVs. For cradle-grave FCVs the use of hydrogen from electrolysis operated with photovoltaic power reduces global warming potential (GWP) by almost 76.4% relative to steam methane reforming. By contrast the use of hydrogen from electrolysis operated with the Chinese electricity grid mix results in an increase in GWP of almost 158.3%.

In this fourth episode Simon Buckley and Matthew Moss from Innovate UK KTN are exploring the use of hydrogen in the global maritime industry alongside their special guest Chester Lewis Business Development Manager at Ryze Hydrogen.

This podcast can be found on their website

The automotive industry sees hydrogen-powered fuel cell(FC) drives as a promising option with a high range and shortrefueling time. Current research aims to increase the profitabil-ity of the fuel cell system by reducing hydrogen consumption.This study suggests the use of an electrochemical hydrogencompressor (EHC) for hydrogen recirculation. Compared tomechanical compressors the EHC is very efficient due to thealmost isothermal conditions and due to its modular structurecan only take up a minimal amount of space in vehicles. Inaddition gas separation and purification of the hydrogentakes place in an EHC which is a significant advantage overthe standard recirculation with a blower or a jet pump. Thehigh purity of the hydrogen at the cathode outlet of the EHCalso increased partial pressure of the hydrogen at the fuel cellinlet and its efficiency. The study carried out shows that repla-cing the blower with the EHC reduces the hydrogen loss bypurging by up to ~95% and the efficiency of the FC systemcould be further improved. Thus the EHC has a great poten-tial for recycling hydrogen in FC systems in the automotiveindustry and is a great alternative to the current blower.

The present paper deals with the investigation at conceptual level of the performance of short–medium-range aircraft with hydrogen propulsion. The attention is focused on the relationship between figures of merit related to transport capability such as passenger capacity and flight range and the parameters which drive the design of liquid hydrogen tanks and their integration with a given aircraft geometry. The reference aircraft chosen for such purpose is a box-wing short–mediumrange airplane the object of study within a previous European research project called PARSIFAL capable of cutting the fuel consumption per passenger-kilometre up to 22%. By adopting a retrofitting approach non-integral pressure vessels are sized to fit into the fuselage of the reference aircraft under the assumption that the main aerodynamic flight mechanic and structural characteristics are not affected. A parametric model is introduced to generate a wide variety of fuselage-tank cross-section layouts from a single tank with the maximum diameter compatible with a catwalk corridor to multiple tanks located in the cargo deck and an assessment workflow is implemented to perform the structural sizing of the tanks and analyse their thermodynamic behaviour during the mission. This latter is simulated with a time-marching approach that couples the fuel request from engines with the thermodynamics of the hydrogen in the tanks which is constantly subject to evaporation and depending on the internal pressure vented-out in gas form. Each model is presented in detail in the paper and results are provided through sensitivity analyses to both the technologic parameters of the tanks and the geometric parameters influencing their integration. The guidelines resulting from the analyses indicate that light materials such as the aluminium alloy AA2219 for tanks’ structures and polystyrene foam for the insulation should be selected. Preferred values are also indicted for the aspect ratios of the vessel components i.e. central tube and endcaps as well as suggestions for the integration layout to be adopted depending on the desired trade-off between passenger capacity as for the case of multiple tanks in the cargo deck and achievable flight ranges as for the single tank in the section.

In this paper a new isolated hybrid system is simulated and analyzed to obtain the optimal sizing and meet the electricity demand with cost improvement for servicing a small remote area with a peak load of 420 kW. The major configuration of this hybrid system is Photovoltaic (PV) modules Biomass gasifier (BG) Electrolyzer units Hydrogen Tank units (HT) and Fuel Cell (FC) system. A recent optimization algorithm namely Mayfly Optimization Algorithm (MOA) is utilized to ensure that all load demand is met at the lowest energy cost (EC) and minimize the greenhouse gas (GHG) emissions of the proposed system. The MOA is selected as it collects the main merits of swarm intelligence and evolutionary algorithms; hence it has good convergence characteristics. To ensure the superiority of the selected MOA the obtained results are compared with other well-known optimization algorithms namely Sooty Tern Optimization Algorithm (STOA) Whale Optimization Algorithm (WOA) and Sine Cosine Algorithm (SCA). The results reveal that the suggested MOA achieves the best system design achieving a stable convergence characteristic after 44 iterations. MOA yielded the best EC with 0.2106533 $/kWh the net present cost (NPC) with 6170134 $ the loss of power supply probability (LPSP) with 0.05993% and GHG with 792.534 t/y.

An uninterrupted chain of energy supplies is the core of every activity without exception for the operations of the North Atlantic Treaty Organization. A robust and efficient energy supply is fundamental for the success of missions and a guarantee of soldier safety. However organizing a battlefield energy supply chain is particularly challenging because the risks and threats are particularly high. Moreover the energy supply chain is expected to be flexible according to mission needs and able to be moved quickly if necessary. In line with ongoing technological changes the growing popularity of hydrogen is undeniable and has been noticed by NATO as well. Hydrogen is characterised by a much higher energy density per unit mass than other fuels which means that hydrogen fuel can increase the range of military vehicles. Consequently hydrogen could eliminate the need for risky refuelling stops during missions as well as the number of fatalities associated with fuel delivery in combat areas. Our research shows that a promising prospect lies in the mobile technologies based on hydrogen in combination with use of the nuclear microreactors. Nuclear microreactors are small enough to be easily transported to their destinations on heavy trucks. Depending on the design nuclear microreactors can produce 1–20 MW of thermal energy that could be used directly as heat or converted to electric power or for non-electric applications such as hydrogen fuel production. The aim of the article is to identify a model of nuclear-hydrogen synergy for use in NATO operations. We identify opportunities and threats related to mobile energy generation with nuclear-hydrogen synergy in NATO operations. The research presented in this paper identifies the best method of producing hydrogen using a nuclear microreactor. A popular and environmentally “clean” solution is electrolysis due to the simplicity of the process. However this is less efficient than chemical processes based on for example the sulphur-iodine cycle. The results of the research presented in this paper show which of the methods and which cycle is the most attractive for the production of hydrogen with the use of mini-reactors. The verification criteria include: the efficiency of the process its complexity and the residues generated as a result of the process (waste)—all taking into account usage for military purposes.

This article proposes a new model of power supply for mobile low power machines applications between 10 W and 30 W such as radio-controlled (RC) electric cars. This power supply is based on general hydrogen from residual aluminum and water with NaOH so it is proposed energy valorization of aluminum waste. In the present research a theoretical model allows us to predict the requested aluminum surface and the required flow of hydrogen has been developed also considering in addition to the geometry and purity of the material two key variables as the temperature and the molarity of the alkaline solution used in the hydrogen production process. Focusing on hydrogen production isopropyl alcohol plays a key role in the reactor’s fuel cell vehicle as it filters out NaOH particles and maintains a constant flow of hydrogen for the operation of the machine keeping the reactor temperature controlled. Finally a comparison of the theoretical and experimental data has been used to validate the developed model using aluminum sheets from ring cans to generate hydrogen which will be used as a source of hydrogen in a power fuel cell of an RC car. Finally the manuscript shows the parts of the vehicle’s powertrain its behavior and mode of operation.

With the decarbonization and electrification of modern railway transportation the demand for both the highcapacity electrical energy and hydrogen fuel energy is increasingly high. A novel scheme was proposed from liquid hydrogen production by surplus wind and solar energy to liquid hydrogen-electricity hybrid energy transmission for railway transportation. The 100 MW hybrid energy transmission pipeline was designed with the 10 kA/1.5 kV superconducting DC cable for electricity and cryogenic layers for liquid hydrogen and liquid nitrogen showing strong capability in transmitting “electricity + cold energy + chemical energy” simultaneously. Economic evaluation was performed with respect to the energy equipment capacity and costs with sensitivity and profitability analysis. With the discount rate 8% the dynamic payback period of the hybrid energy pipeline was 7.1 years. Results indicated that the shortest dynamic payback period of the hybrid energy pipeline was 4.8 years with the maximum transmission distance 93 km. Overall this article shows the novel concept and design of liquid hydrogen-electricity hybrid energy pipelines and proves the technical and economic feasibilities for future bulk hybrid energy transmission for railway transportation.

The hydrogen diffusion behavior and hydrogen embrittlement susceptibility of dual phase (DP) steels with different martensite content were investigated using the slow strain-rate tensile test and hydrogen permeation measurement. Results showed that a logarithmic relationship was established between the hydrogen embrittlement index (IHE) and the effective hydrogen diffusion coefficient (Deff). When the martensite content is low ferrite/ martensite interface behaves as the main trap that captures the hydrogen atoms. Also when the Deff decreases IHE increases with increasing martensite content. However when the martensite content reaches approximately 68.3% the martensite grains start to form a continuous network Deff reaches a plateau and IHE continues to increase. This is mainly related to the reduction of carbon content in martensite and the length of ferrite/martensite interface which promotes the diffusion of hydrogen atoms in martensite and the aggregation of hydrogen atoms at the ferrite/martensite interface. Finally a model describing the mechanism of microstructure-driven hydrogen diffusion with different martensite distribution was established.

The construction of hydrogen refueling stations is an important part of the promotion of fuel cell vehicles. In this paper a multi-period hydrogen refueling station location model is presented that can be applied to the planning and construction of hydrogen infrastructures. Based on the hydrogen demand of fuel cell passenger cars and commercial vehicles the model calculates the hydrogen demand of each zone by a weighting method according to population economic level and education level. Then the hydrogen demand of each period is calculated using the generalized Bass diffusion model. Finally the set covering model is improved to determine the locations of the stations. The new model is applied to the scientific planning of hydrogen refueling stations in Jiading District Shanghai; the construction location and sequence of hydrogen refueling stations in each period are given and the growth trend of hydrogen demand and the promoting effect of hydrogen refueling stations are analyzed. The model adopted in this model is then compared with the other two kinds of node-based hydrogen refueling station location models that have previously been proposed.

Hot water and space heating account for about 80% of total energy consumption in the residential sector in the UK. It is thus crucial to decarbonise residential heating to achieve UK's 2050 greenhouse gas reduction targets. However the decarbonisation transitions determined by most techno-economic energy system models might be too optimistic or misleading for relying on cost minimisation alone and not considering households' preferences for different heating technologies. This study thus proposes a novel framework to incorporate heterogeneous households' (HHs) preferences into the modelling process of the UK TIMES model. The incorporated preferences for HHs are based on a nationwide survey on homeowners' choices of heating technologies. Preference constraints are then applied to regulate the HHs' choices of heating technologies to reflect the survey results. Consequently compared to the least cost transition pathway the preference-driven pathway adopts heating technologies gradually without abrupt increases of market shares. Heat pumps and electric heaters are deployed much less than in the cost optimal result. Extensive district heating using low-carbon fuels and conservation measures should thus be deployed to provide flexibility for decarbonisation. The proposed framework can also incorporate preferences for other energy consumption technologies and be applied to other linear programming based energy system models.

Due to its environmental impact the mobility system is increasingly under pressure. The challenges to cope with climate change air quality depleting fossil resources imply the need for a transition of the current mobility system towards a more sustainable one. Expectations and visions have been identified as crucial in the guidance of such transitions and more specifically of actor strategies. Still it remained unclear why the actors involved in transition activities appear to change their strategies frequently and suddenly. The empirical analysis of the expectations and strategies of three actors in the field of hydrogen and fuel cell technology indicates that changing actor strategies can be explained by rather volatile expectations related to different levels. Our case studies of the strategies of two large car manufacturers and the German government demonstrate that the car manufacturers refer strongly to expectations about the future regime while expectations related to the socio-technical landscape level appear to be crucial for the strategy of the German government.

The need to reduce the climate impact of the transport sector has led to an increasing interest in the utilisation of alternative fuels. Producing advanced fuels through the integration of anaerobic digestion and power-to-fuel technologies may offer a solution to reduce greenhouse gas emissions from difficult to decarbonise modes of transport such as heavy goods vehicles shipping and commercial aviation while also offering wider system benefits. This paper investigates the energy balance of power-to-fuel (power-to-methane power-to-methanol power-to-Fischer-Tropsch fuels) production integrated with a biogas facility co-digesting grass silage and dairy slurry. Through the integration of power-to-methane with anaerobic digestion an increase in system gross energy of 62.6% was found. Power-to-methanol integration with the biogas system increased the gross energy by 50% while power-to-Fischer-Tropsch fuels increased the gross energy yield by 32%. The parasitic energy demand for hydrogen production was highlighted as the most significant factor for integrated biogas and power-to-fuel facilities. Consuming electricity that would otherwise have been curtailed and optimising the anaerobic digestion process were identified as key to improving the energetic efficiency of all system configurations. However the broad cross-sectoral benefits of the overarching cascading circular economy system such as providing electrical grid stability and utilising waste resources must also be considered for a comprehensive perspective on the integration of anaerobic digestion and power-to-fuel.

The UK is investigating supplying hydrogen to homes and businesses instead of natural gas by “repurposing” the gas network. It presents a major engineering challenge which has never been done anywhere else in the world.

In a new report titled ‘Transitioning to hydrogen’ experts from a cross-professional engineering institution (PEI) working group including the IET have assessed the engineering risks and uncertainties and concluded there is no reason why repurposing the gas network to hydrogen cannot be achieved. But there are several engineering risks and uncertainties which need to be addressed.

The modern steelmaker of advanced high-strength steels has always been challenged with the conflicting targets of increased strength while maintaining or improving ductility. These new steels help the transportation sector including the automotive sector to achieve the goals of increased passenger safety and reduced emissions. With increasing tensile strengths certain steels exhibit an increased sensitivity towards hydrogen embrittlement (HE). The ability to characterize the material's sensitivity in an as-delivered condition has been developed and accepted (SEP1970) but the complexity of the stress states that can induce an embrittlement together with the wide range of applications for high-strength steels make the development of a standardized test for HE under in-service conditions extremely challenging. Some proposals for evaluating the material's sensitivity give an advantage to materials with a low starting ductility. Despite this newly developed materials can have a higher original elongation with only a moderate reduction in elongation due to hydrogen. This work presents a characterization of new materials and their sensitivity towards HE.

This article is part of the themed issue ‘The challenges of hydrogen and metals’.

Link to document download on Royal Society Website 

Experimental research on performance and emissions of engine fuelled with low calorific value gas blended with hydrogen was carried out and indicated thermal efficiency engine torque indicator diagram pressure rise rate and emissions with different hydrogen ratios were also analyzed. Experimental results show that with the increase of hydrogen fraction and CNG fraction in mixtures the indicated thermal efficiency increased. The engine power output is influenced by both low calorific value and hydrogen fractions. With the increase of hydrogen fraction in mixtures HC emissions decrease CO and NOx emissions increase. An engine operating on lean-burn low calorific value gas blended with hydrogen is favourable for getting lower emissions.

A fuel cell—gas turbine hybrid propulsion concept is introduced and initially assessed. The concept uses the water mass flow produced by a hydrogen fuel cell in order to improve the efficiency and power output of the gas turbine engine through burner steam injection. Therefore the fuel cell product water is conditioned through a process of condensation pressurization and revaporization. The vaporization uses the waste heat of the gas turbine exhaust. The functional principles of the system concept are introduced and discussed and appropriate methodology for an initial concept evaluation is formulated. Essential technology fields are surveyed in brief. The impact of burner steam injection on gas turbine efficiency and sizing is parametrically modelled. Simplified parametric models of the fuel cell system and key components of the water treatment process are presented. Fuel cell stack efficiency and specific power levels are methodically derived from latest experimental studies at the laboratory scale. The overall concept is assessed for a liquid hydrogen fueled short-/medium range aircraft application. Block fuel savings of up to 7.1% are found for an optimum design case based on solid oxide fuel cell technology. The optimum design features a gas turbine water-to-air ratio of 6.1% in cruise and 62% reduced high-level NOx emissions.

The Climate Change Committee (CCC) commissioned Element Energy to improve our evidence base on the potential of industrial deep-decarbonisation measures (fuel switching CCS/BECCS measures to reduce methane emissions) and develop pathways for their application. This report summarises the evidence and results of the work including:

• Evidence on the key constraints and costs for technology and infrastructure deployment
• The methodology and new Net Zero Industry Pathway (N-ZIP) model used to determine deep-decarbonisation pathways for UK industry (drawing on the evidence above)
• A set of pathways and wider sensitivities produced using the N-ZIP model which fed into the CCC’s Sixth Carbon Budget pathways
• Recommended actions and policy measures as informed by the study.

A potential solution to reduce greenhouse gas (GHG) emissions in the transport sector is to use alternatively fuelled vehicles (AFV). Heavy-duty vehicles (HDV) emit a large share of GHG emissions in the transport sector and are therefore the subject of growing attention from global regulators. Fuel cell and green hydrogen technologies are a promising option to decarbonize HDVs as their fast refuelling and long vehicle ranges are consistent with current logistic operational requirements. Moreover the application of green hydrogen in transport could enable more effective integration of renewable energies (RE) across different energy sectors. This paper explores the interplay between HDV Hydrogen Refuelling Stations (HRS) that produce hydrogen locally and the power system by combining an infrastructure location planning model and an electricity system optimization model that takes grid expansion options into account. Two scenarios – one sizing refuelling stations to support the power system and one sizing them independently of it – are assessed regarding their impacts on the total annual electricity system costs regional RE integration and the levelized cost of hydrogen (LCOH). The impacts are calculated based on locational marginal pricing for 2050. Depending on the integration scenario we find average LCOH of between 4.83 euro/kg and 5.36 euro/kg for which nodal electricity prices are the main determining factor as well as a strong difference in LCOH between north and south Germany. Adding HDV-HRS incurs power transmission expansion as well as higher power supply costs as the total power demand increases. From a system perspective investing in HDV-HRS in symbiosis with the power system rather than independently promises cost savings of around seven billion euros per annum. We therefore conclude that the co-optimization of multiple energy sectors is important for investment planning and has the potential to exploit synergies.

This report assesses the potential of hydrogen (H2) propulsion to reduce aviation’s climate impact. To reduce climate impact the industry will have to introduce further levers such as radically new technology significantly scale sustainable aviation fuels (SAF) such as synthetic fuel (synfuel) temporarily rely on offsets in large quantities or rely on a combination thereof. H2 propulsion is one such technology and this report assesses its potential in aviation. Developed with input from leading companies and research institutes it projects the technological development of H2 combustion and fuel cell-powered propulsion evaluates their technical and economic feasibility compares them to synfuel and considers implications on aircraft design airport infrastructure and fuel supply chains.

Extensive energy consumption has become a major concern due to increase of greenhouse gas emissions and global warming. Hence hydrogen has attracted attention as a green fuel with zero carbon emission for green transportation through production of electric vehicles with hydrogen fuel cells. South Korea has launched a hydrogen society policy with the objective of expanding production of hydrogen from renewable energy sources. The hydrogen economy will play a critical role in reducing atmospheric pollution and global  arming. However new development of infrastructure for hydrogen refuelling and increasing awareness of the hydrogen economy is required together with reduced prices of hydrogen-driven vehicles that are promising options for a sustainable green  hydrogen economy.

The Fuel Cells and Hydrogen Joint Undertaking (FCH JU) has supported a range of initiatives in recent years designed to develop hydrogen fuel cell buses to a point where they can fulfil their promise as a mainstream zero emission vehicle for public transport.<br/>Within this study 90 different European cities and regions have been supported in understanding the business case of fuel cell bus deployment and across these locations. The study analyses the funding and financing for fuel cell bus deployment to make them become a mainstream zero emission choice for public transport providers in cities and regions across Europe. It also outlines possible solutions for further deployment of FC buses beyond the subsidised phase.<br/>In the light of the experience of the joint tender process in the UK and in Germany the study highlights best practices for ordering fuel cell buses. Other innovative instruments explored in other countries for the orders of large quantities of fuel cells buses are presented: Special Purpose Vehicles and centralised purchase office. Finally the study deeply analyses the funding and financing for fuel cell bus deployment to make them become a mainstream zero emission choice for public transport providers in cities and regions across Europe.

Fuel cell electric vehicles (FCEVs) are zero tailpipe emission vehicles. Their large-scale deployment is expected to play a major role in the de-carbonization of transportation in the European Union (EU) and is therefore an important policy element at EU and Member State level.<br/>For FCEVs to be introduced to the market a network of hydrogen refuelling stations (HRS) first has to exist. From a technological point of view FCEVs are ready for serial production already: Hyundaiand Toyota plan to introduce FCEVs into key markets from 2015 and Daimler Ford and Nissan plan to launch mass-market FCEVs in 2017.<br/>At the moment raising funds for building the hydrogen refuelling infrastructure appears to be challenging.<br/>This study explores options for financing the HRS rollout which facilitate the involvement of private lenders and investors. It  presents a number of different financing options involving public-sector bank loans funding from private-sector strategic equity investors commercial bank loans private equity and funding from infrastructure investors. The options outline the various requirements forn accessing these sources of funding with regard to project structure incentives and risk mitigation. The financing options were developed on the basis of discussions with stakeholders in the HRS rollout from industry and with financiers.<br/>This study was prepared by Roland Berger in close contact with European Investment banks and a series of private banks.<br/>This study explores in details the business cases for HRS in Germany and UK. The conclusion can be easily extrapolate to other countries.

This brochure offers an overview of the main applications of fuel cell and hydrogen technologies and how they work and provides insights into our programme and our accomplishments.

Addressing the pressing challenge of global warming reducing greenhouse gas emissions in the transportation sector is a critical imperative. Battery and fuel cell electric vehicles have emerged as promising solutions for curbing emissions in this sector. In this study we conducted a comprehensive life cycle assessment (LCA) for typical passenger vehicles heavy-duty trucks and city buses using either proton-exchange membrane fuel cells or Li-ion batteries with different cell chemistries. To ensure accuracy we supplemented existing studies with data from the literature particularly for the recycling phase as database limitations were encountered. Our results highlight that fuel cell and battery systems exhibit large emissions in the production phase. Recycling can significantly offset some of these emissions but a comparison of the technologies examined revealed considerable differences. Overall battery electric vehicles consistently outperform fuel cell electric vehicles regarding absolute greenhouse gas emissions. Hence we recommend prioritizing battery electric over fuel cell vehicles. However deploying fuel cell electric vehicles could become attractive in a hydrogen economy scenario where other factors e. g. the conversion and storage of surplus renewable electricity via electrolysis become important.

Interest in reducing the greenhouse gas emissions from conventional power generation has increased the focus on the potential use of hydrogen to produce electricity. Numerous life-cycle assessment (LCA) studies of hydrogen-based power generation have been published. This study reviews the technological and methodological choices made in hydrogen-based power generation LCAs. A systematic review was chosen as the research method to achieve a comprehensive and minimally biased overview of hydrogen-based power generation LCAs. Relevant articles published between 2004 and 2021 were identified by searching the Scopus and Web of Science databases. Electrolysis from renewable energy resources was the most widely considered type of hydrogen production in the LCAs analyzed. Fuel cell technology was the most common conversion equipment used in hydrogen-based electricity LCAs. A significant number of scenarios examine the use of hydrogen for energy storage and co-generation purposes. Based on qualitative analysis the methodological choices of LCAs vary between studies in terms of the functional units allocations system boundaries and life-cycle impact assessment methods chosen. These discrepancies were likely to influence the value of the environmental impact results. The findings of the reviewed LCAs could provide an environmental profile of hydrogen-based electricity systems identify hotspots drive future research define performance goals and establish a baseline for their large-scale deployment.

The proton exchange membrane fuel cell (PEMFC) is a promising device in the fields of power generation energy storage aerospace and public transportation. The hydrogen recirculation ejector with the advantages of low cost high durability and no parasitic power is the key component of PEMFC systems. However it is challenging to design a hydrogen recirculation ejector to cover the wide operating conditions of PEMFC systems. In order to design an ejector for fuel cell systems a comprehensive understanding of ejector research is required. Consequently the state-of-the-art research work on the hydrogen recirculation ejector is analyzed including characteristics of the ejector in PEM fuel cell systems geometry design and optimization different types of ejectors and a comparison between them and system integration and control. Through a comprehensive analysis of ejectors further research suggestions on designing high-performance ejectors are presented.

The coal industry contributes significantly to the social economy but the emission of greenhouse gases puts huge pressure on the environment in the process of mining transportation and power generation. In the integrated energy system (IES) the current research about the power-to-gas (P2G) technology mainly focuses on the injection of hydrogen generated from renewable energy electrolyzed water into natural gas pipelines which may cause hydrogen embrittlement of the pipeline and cannot be repaired. In this paper sufficient hydrogen energy can be produced through P2G technology and coal-to-hydrogen (C2H) of coal gasification considering the typical scenario of coal district is rich in coal and renewable energy. In order to transport the mined coal to the destination hydrogen heavy trucks have a broad space for development which can absorb hydrogen energy in time and avoid potentially dangerous hydrogen injection into pipelines and relatively expensive hydrogen storage. An optimized scheduling model of electric-gas IES is proposed based on second-order cone programming (SOCP). In the model proposed above the closed industrial loop (including coal mining hydrogen production truck transportation of coal and integrated energy systems) has been innovatively studied to consume renewable energy and coordinate multi-energy. Finally an electric-gas IES study case constructed by IEEE 30-node power system and Belgium 24-node natural gas network was used to analyze. The results show that by introducing the proposed hydrogen production technology typical daily operating costs are effectively reduced by 7.7%. Under China’s carbon emissions trading system the operating costs of hydrogen heavy trucks have been reduced by 0.95 and 4.68% respectively compared with electric vehicles and diesel trucks. Under Europe’s stricter carbon emissions trading system the percentages of cost reduction are 2.56 and 9.12% respectively. The above technical results verify the feasibility economy low carbon and effectiveness of the proposed mechanism.

To achieve future emission targets for internal combustion engines the use of hydrogen gas generated by renewable energy sources (known as “green” hydrogen) instead of fossil fuels plays a key role in the development of new combustion-based engine concepts. For new hydrogen engine generations there are different challenges concerning the injector layout and functionality. Especially when talking about direct hydrogen injection the key challenge is to ensure a proper mixing between hydrogen and the combustion air—the mixing of gas with a gas is not trivial as shown in this article. In terms of injector functionality it must be ensured that the requested amount of hydrogen gas needs to be provided in time and on the other hand accurately metered to provide an appropriate mixing formation quality inside the combustion chamber. This contribution discusses deep injector analysis techniques with pneumatic and optical approaches for an improved overall understanding of functionality and effects caused by operation with a gaseous fuel. A metering technique for gas flow characterization and for test simplification a comparison of hydrogen with helium and nitrogen as possible surrogate gases indicate that helium and nitrogen can act as a substitute for hydrogen in functional testing. Furthermore this contribution focuses on the usability of helium instead of hydrogen for the determination of spray properties. This is shown by the comparison of spray propagation images that were observed with the Schlieren technique in a pressure vessel proving comparable spray properties. In a next step the usage of spray-guiding devices to improve the global gas distribution during the injection period is discussed. Here it turns out that the volume increase does obviously not depend on the nozzle design. Thus the advantage of multi-hole guiding-devices is based on its flexible gas-jet orientation.

To alleviate the global warming crisis carbon reduction is an inevitable trend of sustainable development. The energy carrier with Hydrogen (H2) is considered to be one of the promising choices for realizing a low-carbon economy. With the increasing penetration level of wind power generation and for well-balancing wind generation fluctuations this paper proposes a low-carbon economic dispatch method for power systems based on mobile hydrogen storage(MHS). The wind power surplus during off-peak load periods is first utilized to generate green H2. Afterward the green H2 is optimally transported to multiple hydrogen storage(HS) stations for generating power electricity by flexibly controlling the electrolysis(EL) methanation(ME) carbon capture(CCS) and H2 power generation processes in such a way the wind power is coordinated with the hydrogen production transport and utilization to reduce the total carbon emission and minimize the operation cost of power systems. Finally the proposed power system low-carbon economic dispatch model is verified by case studies.

Green ammonia has received increasing interest for its potential as an energy carrier in the international trade of renewable power. This paper considers the factors that contribute to producing cost-competitive green ammonia from an exporter’s perspective. These factors include renewable resource quality across potential sites operating modes for off-grid plants and seasonal complementarity with trade buyers. The study applies a mixed-integer programming model and uses Australia as a case study because of its excellent solar and wind resources and the potential for synergy between Southern Hemisphere supply and Northern Hemisphere demand. Although renewable resources are unevenly distributed across Australia and present distinct diurnal and seasonal variability modelling shows that most of the pre-identified hydrogen hubs in each state and territory of Australia can produce cost-competitive green ammonia providing the electrolysis and Haber-Bosch processes are partially flexible to cope with the variability of renewables. Flexible operation reduces energy curtailment and leads to lower storage capacity requirements using batteries or hydrogen storage which would otherwise increase system costs. In addition an optimised combination of wind and solar can reduce the magnitude of storage required. Providing that a partially flexible Haber Bosch plant is commercially available the modelling shows a levelised cost of ammonia (LCOA) of AU$756/tonne and AU$659/tonne in 2025 and 2030 respectively. Based on these results green ammonia would be cost-competitive with grey ammonia in 2030 given a feedstock natural gas price higher than AU$14/MBtu. For green ammonia to be cost-competitive with grey ammonia assuming a lower gas price of AU$6/MBtu a carbon price would need to be in place of at least AU$123/tonne. Given that there is a greater demand for energy in winter concurrent with lower solar power production there may be opportunities for solar-based Southern Hemisphere suppliers to supply the major industrial regions most of which are located in the Northern Hemisphere.

The optimal design of off-grid hybrid renewable energy systems (HRESs) is a challenging task which often involves conflicting goals to be faced. In this work levelized cost of energy (LCOE) and CO2 emissions have been addressed simultaneously by using the ε-constraint method together with the particle swarm optimization (PSO) algorithm. Cost-emissions Pareto fronts of different HRES configurations were developed to gain greater awareness about the potential of renewable-based energy systems in off-grid applications. Various combinations of the following components were investigated: photovoltaic panels wind turbines batteries hydrogen and diesel generators. The hydrogen-based system comprises an electrolyzer to convert the excess renewable energy into hydrogen a pressurized tank for H2 storage and a fuel cell for the reconversion of hydrogen into electricity during renewable energy deficits. Electrolyzer and fuel cell devices were modelled by means of part-load performance curves. Size-dependent costs and component lifetimes as a function of the cumulative operational duty were also considered for a more accurate techno-economic assessment. The proposed methodology was applied to the Froan islands (Norway) which were chosen as a reference case study since they are well representative of many other insular microgrid environments in Northern Europe. Results from the sizing simulations revealed that energy storage devices are key components to reduce the dependency on fossil fuels. In particular the hydrogen storage system is crucial in off-grid areas to enhance the RES penetration and avoid a sharp increase in the cost of energy. Hydrogen in fact allows the battery and RES technologies not to be oversized thanks to its cost-effective long-term storage capability. Concerning the extreme case with no diesel the cheapest configuration which includes both batteries and hydrogen has an LCOE of 0.41 €/kWh. This value is around 35% lower than the LCOE of a system with only batteries as energy storage.

To reduce greenhouse gases and air pollutants new technologies are emerging to reduce fossil fuel usage and to adopt more renewable energy sources. As the major aspects of fuel consumption power generation transportation and industrial applications have been given significant attention. The past few decades witnessed astonishing technological advancement in these energy sectors. In contrast the residential sector has had relatively little attention despite its significant utilization of fuels for a much longer period. However almost every energy transition in human history was initiated by the residential sector. For example the transition from fuelwood to cheap coal in the 1700s first took place in residential houses due to urbanization and industrialization. The present review demonstrates the energy transitions in the residential sector during the past two centuries while portending an upcoming energy transition and future energy structure for the residential sector. The feasibility of the 100% electrification of residential buildings is discussed based on current residential appliance adoption and the analysis indicates a hybrid residential energy structure is preferred over depending on a single energy source. Technical considerations and suggestions are given to help incorporate more renewable energy into the residential fuel supply system. Finally it is observed that compared to the numerous regulations on large energy-consumption aspects standards for residential appliances are scarce. Therefore it is concluded that establishing appropriate testing methods is a critical enabling step to facilitate the adoption of renewable fuels in future appliances.

Power-to-gas (P2G) facilities use surplus electricity to convert to natural gas in integrated energy systems (IES) increasing the capacity of wind power to be consumed. However the capacity limitation of P2G and the antipeaking characteristic of wind power make the wind abandonment problem still exist. Meanwhile the oxygen generated by P2G electrolysis is not fully utilized. Therefore this study proposes a low-carbon economic dispatch model considering the utilization of hydrogen and oxygen energy. First the two-stage reaction model of P2G is established and the energy utilization paths of hydrogen blending and oxygen-rich deep peaking are proposed. Specifically hydrogen energy is blended into the gas grid to supply gas-fired units and oxygen assists oxygenrich units into deep peaking. Subsequently the stochastic optimization is used to deal with the uncertainty of the system and the objective function and constraints of the IES are given to establish a low-carbon dispatch model under the energy utilization model. Finally the effectiveness of the proposed method is verified based on the modified IEEE 39-node electric network 20-node gas network and 6-node heat network models.

Industries account for about 30% of total final energy consumption worldwide and about 20% of global CO2 emissions. While transitions towards renewable energy have occurred in many parts of the world in the energy sectors the industrial sectors have been lagging behind. Decarbonising the energy-intensive industrial sectors is however important for mitigating emissions leading to climate change. This paper analyses various technological trajectories and key policies for decarbonising energy-intensive industries: steel mining and minerals cement pulp and paper and refinery. Electrification fuel switching to low carbon fuels together with technological breakthroughs such as fossil-free steel production and CCS are required to bring emissions from energy-intensive industry down to net-zero. A long-term credible carbon price support for technological development in various parts of the innovation chain policies for creating markets for low-carbon materials and the right condition for electrification and increased use of biofuels will be essential for a successful transition towards carbon neutrality. The study focuses on Sweden as a reference case as it is one of the most advanced countries in the decarbonisation of industries. The paper concludes that it may be technically feasible to deep decarbonise energy-intensive industries by 2045 given financial and political support.

The uncertainty and volatility of wind power have led to large-scale wind curtailment during grid connections. The adoption of power-to-hydrogen (P2H) system in a microgrid (MG) can mitigate the renewable curtailment by hydrogen conversion and storage. This paper conducts unified modeling for different types of P2H systems and considers the multi-energy trading in a hydrogen-coupled power market. The proposed bi-level equilibrium model is beneficial to minimize the energy cost of microgrids. Firstly a microgrid operation model applied to different P2H systems including an alkaline electrolysis cell (AEC) a proton exchange membrane electrolysis cell (PEMEC) or a solid oxide electrolysis cell (SOEC) is proposed at the upper level. Secondly an electricity market–clearing model and a hydrogen market model are constructed at the lower level. Then the diagonalization algorithm is adopted to solve the multi-market equilibrium problem. Finally case studies based on an IEEE 14-bus system are conducted to validate the proposed model and the results show that the microgrid with a P2H system could gain more profits and help increase the renewable penetration.