Publications

In future energy supply systems hydrogen and electricity may be generated in decarbonized industrial clusters using a common infrastructure for natural gas supply electricity grid and transport and geological storage of CO_2. The novel contribution of this article consists of using sequential combustion in a steam methane reforming (SMR) hydrogen plant to allow for capital and operating cost reduction by using a single post-combustion carbon capture system for both the hydrogen process and the combined cycle gas turbine (CCGT) power plant plus appropriate integration for this new equipment combination. The concept would be widely applied to any post-combustion CO₂ capture process. A newly developed rigorous gPROMs model of two hydrogen production technologies covering a wide range of hydrogen production capacities thermodynamically integrated with commercially available gas turbine engines quantifies the step change in thermal efficiency and hydrogen production efficiency. It includes a generic post-combustion capture technology – a conventional 30%wt MEA process - to quantify the reduction in size of CO₂ absorber columns the most capital intensive part of solvent-based capture systems. For a conventional SMR located downstream of an H-class gas turbine engine followed by a three-pressure level HRSG and a capture plant with two absorbers the integrated system produces ca. 696400 Nm3/h of H₂ with a net power output of 651 MWe at a net thermal efficiency of 38.9%LHV. This corresponds to 34 MWe of additional power increasing efficiency by 4.9% points and makes one absorber redundant compared to the equivalent non-integrated system producing the same volume of H₂. For a dedicated gas heated reformer (GHR) located downstream of an aeroderivative gas turbine engine followed by a two-pressure level HRSG and a capture plant with one absorber the integrated system produces ca. 80750 Nm3/h of H₂ with a net power output of 73 MWe and a net thermal efficiency of 54.7%LHV. This corresponds to 13 MWe of additional power output increasing efficiency by 13.5% points and also makes one absorber redundant. The article also presents new insights for the design and operation of reformers integrated with gas turbines and with CO₂ capture.

The Swiss government has signed the Paris Climate Agreement and various measures need to be implemented in order to reach the target of a 50% reduction in CO₂ emissions in Switzerland by 2030 compared with the value for 1990. Considering the fact that the production of cement in Switzerland accounts around 2.5 million ton for CO₂ emissions of which corresponds to roughly 7% of the country's total CO₂ emissions the following article examines how this amount could be put to meaningful use in order to create a new value-added chain through CO₂ methanation and thus reduce the consumption and import of fossil fuels in Switzerland. With power-to-gas technology this CO₂  along with regenerative hydrogen from photovoltaics can be converted into methane which can then be fed into the existing natural-gas grid. This economic case study shows a cost prediction for conversion of all the CO₂ from the cement industry into methane by using the technologies available today in order to replacing fossil methane imports.

Safe and long term operation of nuclear reactors is one of the most discussed challenges in nuclear power engineering. The radiation degradation of nuclear design materials limits the operational lifetime of all nuclear installations or at least decreases its safety margin. This paper is a review of experimental PALS/PLEPS studies of different nuclear reactor pressure vessel (RPV) steels investigated over last twenty years in our laboratories. Positron annihilation lifetime spectroscopy (PALS) via its characteristics (lifetimes of positrons and their intensities) provides useful information about type and density of radiation induced defects. The new results obtained on neutron-irradiated and hydrogen ions implanted German steels were compared to those from the previous studies with the aim to evaluate different processes (neutron flux/fluence thermal treatment or content of selected alloying elements) to the microstructural changes of neutron irradiated RPV steel specimens. The possibility of substitution of neutron treatment (connected to new defects creation) via hydrogen ions implantation was analyzed as well. The same materials exposed to comparable displacement damage (dpa) introduced by neutrons and accelerated hydrogen ions shown that in the results interpretation the effect of hydrogen as a vacancy-stabilizing gas must be considered too. This approach could contribute to future studies of nuclear fission/fusion design steels treated by high levels of neutron irradiation.

The generation of hydrogen from water using light is currently one of the most promising alternative energy sources for humankind but faces significant barriers for large-scale applications due to the low efficiency of existing photo-catalysts. In this work we propose a new route to fabricate nano-hybrid materials able to deliver enhanced photo-catalytic hydrogen evolution combining within the same nanostructure a plasmonic antenna nanoparticle and semiconductor quantum dots (QDs). For each stage of our fabrication process we probed the chemical composition of the materials with nanometric spatial resolution allowing us to demonstrate that the final product is composed of a silver nanoparticle (AgNP) plasmonic core surrounded by satellite Pt decorated CdS QDs (CdS@Pt) separated by a spacer layer of SiO2 with well-controlled thickness. This new type of photoactive nanomaterial is capable of generating hydrogen when irradiated with visible light displaying efficiencies 300% higher than the constituting photo-active components. This work may open new avenues for the development of cleaner and more efficient energy sources based on photo-activated hydrogen generation.

The storage of hydrogen gas in underground lined rock caverns (LRCs) enables the implementation of the first fossil-free steelmaking process to meet the large demand for crude steel. Predicting the response of rock mass is important to ensure that gas leakage due to rupture of the steel lining does not occur. Analytical and numerical models can be used to estimate the rock mass response to high internal pressure; however the fitness of these models under different in situ stress conditions and cavern shapes has not been studied. In this paper the suitability of analytical and numerical models to estimate the maximum cavern wall tangential strain under high internal pressure is studied. The analytical model is derived in detail and finite element (FE) models considering both two-dimensional (2D) and three-dimensional (3D) geometries are presented. These models are verified with field measurements from the LRC in Skallen southwestern Sweden. The analytical model is inexpensive to implement and gives good results for isotropic in situ stress conditions and large cavern heights. For the case of anisotropic horizontal in situ stresses as the conditions in Skallen the 3D FE model is the best approach

Purpose- To present an overview of the research and development carried out in a European funded framework 7 (FP7) project called SafeHPower for the implementation of neutron radiography to inspect fatigue cracks in vehicle and storage hydrogen fuel tanks. Project background– Hydrogen (H2) is the most promising replacement fuel for road transport due to its abundance efficiency low carbon footprint and the absence of harmful emissions. For the mass market of hydrogen to take off the safety issue surrounding the vehicle and storage hydrogen tanks needs to be addressed. The problem is the residual and additional stresses experienced by the tanks during the continuous cyclic loading between ambient and storage pressure which can result in the development of fatigue cracks. Steel tanks used as storage containers at service stations and depots and/or the composite tanks lined with steel are known to suffer from hydrogen embrittlement (HE). Another issue is the explosive nature of hydrogen (when it is present in the 18-59% range) where it is mixed with oxygen which can lead to catastrophic consequences including loss of life. Monitoring systems that currently exist in the market impose visual examination tests pressure tests and hydrostatic tests after the tank installation [1] [2]. Three inspection systems have been developed under this project to provide continuous monitoring solutions. Approach and scope- One of the inspection systems based on the neutron radiography (NR) technology that was developed in different phases with the application of varied strategies has been presented here. Monte Carlo (MCNP) simulation results to design and develop a bespoke collimator have been presented. A limitation of using an inertial electrostatic Deuterium-Tritium (D-T) pulsed neutron generator for fast neutron radiography has been discussed. Radiographs from the hydrogen tank samples obtained using thermal neutrons from a spallation neutron source at ISIS Rutherford laboratory UK have been presented. Furthermore radiograph obtained using thermal neutrons from a portable D-T neutron generator has been presented. In conclusion a proof in principle has been made to show that the defects in the hydrogen fuel tank can be detected using thermal neutron radiography.

Hydrogen production is critical to many modern chemical processes – ammonia synthesis petroleum refining direct reduction of iron and more. Conventional approaches to hydrogen manufacture include steam methane reforming and autothermal reforming which today account for the lion's share of hydrogen generation. Without CO₂ capture these processes emit about 8.7 kg of CO₂ for each kg of H₂ produced. In this study a molten carbonate fuel cell system with CO₂ capture is proposed to retrofit the flue gas stream of an existing Steam Methane Reforming plant rated at 100000 Nm3 h−1 of 99.5% pure H2. The thermodynamic analysis shows direct CO₂ emissions can be reduced by more than 95% to 0.4 to 0.5 kg CO₂ /kg H₂ while producing 17% more hydrogen (with an increase in natural gas input of approximately 37%). Because of the additional power and hydrogen generation of the carbonate fuel cell the efficiency debit associated with CO₂ capture is quite small reducing the SMR efficiency from 76.6% without capture to 75.6% with capture. In comparison the use of standard amine technology for CO2 capture reduces the efficiency below 70%. This demonstrates the synergistic nature of the carbonate fuel cells which can reform natural gas to H₂ while simultaneously capturing CO₂ from the SMR flue gas and producing electricity giving rise to a total system with very low emissions yet high efficiency.

This paper proposes the use of the Point Method (PM) to analyse Environmentally Assisted Cracking (EAC) processes in steels containing U-shaped notches. The PM a methodology included within the Theory of Critical Distances (TCD) has been extensively validated by many authors for the analysis of fracture and fatigue phenomena of different types of materials containing notches. However it has never been applied to other critical or subcritical cracking processes such as EAC or creep crack propagation.<br/>This work provides a PM-based analysis of EAC emanating from notches which is validated by testing CT notched specimens of X80 and S420 steels subjected to aggressive environments under hydrogen embrittlement conditions.<br/>The results reveal that the PM accurately predicts the crack propagation onset condition as well as the evolution of the material’s apparent EAC resistance.

This paper has experimentally proved that hydrogen accumulates in large quantities in metal-ceramic and pocket electrodes of alkaline batteries during their operation. Hydrogen accumulates in the electrodes in an atomic form. After the release of hydrogen from the electrodes a powerful exothermic reaction of atomic hydrogen recombination with a large energy release occurs. This exothermic reaction is the cause of thermal runaway in alkaline batteries. For the KSL-15 battery the gravimetric capacity of sintered nickel matrix of the oxide-nickel electrode as hydrogen storage is 20.2 wt% and cadmium electrode is 11.5 wt%. The stored energy density in the metal-ceramic matrix of the oxide-nickel electrode of the battery KSL-15 is 44 kJ/g and in the cadmium electrode it is 25 kJ/g. The similar values for the KPL-14 battery are as follows. The gravimetric capacity of the active substance of the pocket oxide-nickel electrode as a hydrogen storage is 22 wt% and the cadmium electrode is 16.9 wt%. The density of the stored energy in the active substance oxide-nickel electrode is 48 kJ/g and in the active substance of the cadmium electrode it is 36.8 kJ/g. The obtained results of the accumulation of hydrogen energy in the electrodes by the electrochemical method are three times higher than any previously obtained results using the traditional thermochemical method.

Hydrogen storage is a materials science challenge because for all six storage methods currently being investigated materials with either a strong interaction with hydrogen or without any reaction are needed. Besides conventional storage methods i.e. high pressure gas cylinders and liquid hydrogen the physisorption of hydrogen on materials with a high specific surface area hydrogen intercalation in metals and complex hydrides and storage of hydrogen based on metals and water are reviewed.

The effect of hydrogen on tensile behavior and fracture mechanisms of V-alloying and V-free high-nitrogen austenitic steels was evaluated. Two steels with the chemical compositions of Fe-23Cr–17Mn–0.1C–0.6N (0V-HNS) and Fe-19Cr–22Mn–1.5V–0.3C–0.9N (1.5V-HNS) were electrochemically hydrogen-charged in NaCl water-solution for 100 hours. According to X-ray diffraction analysis and TEM researches V-alloying promotes particle strengthening of the 1.5V-HNS. Despite differences in chemical compositions namely carbon and nitrogen concentrations a solid solution hardening is similar for both steels because of precipitate-assisted depletion of austenite by interstitial atoms (carbon and nitrogen) in 1.5V-HNS. For hydrogen-free state the values of the yield stress and the tensile strength are higher for particle-strengthened 1.5V-HNS as compared to 0V-HNS. Hydrogen-charging increases both the yield stress and the tensile strength of the steels but hydrogen-assisted fracture micromechanisms are different for 0V-HNS and 1.5V-HNS. Hydrogen-charging drastically reduces a total elongation in 0V-HNS but provides insufficient embrittlement in 1.5V-HNS. Hydrogen-assisted brittle layers form on lateral surfaces of the specimens and the widths and fracture micromechanisms in them are different for two steels. For 0V-HNS surface layers of 84 μm in width possess transgranular brittle fracture mechanism (quasi-cleavage mode). For 1.5V-HNS the brittle surface layers (31 μm width) destroy in intergranular brittle fracture mode. The central parts of steel specimens show dimple fracture similar to hydrogen-free steels. The possible reasons for different hydrogen-induced effects in 0V-HNS and 1.5V-HNS are discussed.

2020: a great year for hydrogen! Among other things 2020 has been exceptional for H2 technology deployment and policy development. The European Commission’s hydrogen strategy is just one of many crowning achievements! What does the future hold?

An energy system centred on renewable energy can help resolve many of Africa’s social economic health and environmental challenges. A profound energy transition is not only feasible it is essential for a climate-safe future in which sustainable development prerogatives are met. Renewables are key to overcoming energy poverty providing needed energy services without damaging human health or ecosystems and enabling a transformation of economies in support of development and industrialisation.

Africa is extraordinarily diverse and no single approach will advance its energy future. But efforts must be made to build modern resilient and sustainable energy systems across the continent to avoid trapping economies and societies in increasingly obsolete energy systems that burden them with stranded assets and limited economic prospects.

This report from the International Renewable Energy Agency (IRENA) sets out the opportunities at hand while also acknowledging the challenges Africa faces. It lays out a pathway to a renewables-based energy system and shows that the transition promises substantial gains in GDP employment and human welfare in each region of the continent.

Among the findings:

A large part of Africa has so far been left out of the energy transition:

• Only 2% of global investments in renewable energy in the last two decades were made in Africa with significant regional disparities
• Less than 3% of global renewables jobs are in Africa
• In Sub-Saharan Africa electrification rate was static at 46% in 2019 with 906 million people still lacking access to clean cooking fuels and technologies

But the continent has enormous potential:

• Africa has vast resource potential in wind solar hydro and geothermal energy and falling costs are increasingly bringing renewables within reach
• Central and Southern Africa have abundant mineral resources essential to the production of electric batteries wind turbines and other low-carbon technologies

The last decade has seen progress:

• Renewable energy deployment has grown in the last decade with more than 26 GW of renewables-based generation capacity added. The largest additions were in solar energy
• Average annual investments in renewable energy grew ten-fold from less than USD 0.5 billion in the 2000-2009 period to USD 5 billion in 2010-2020
• Distributed renewable energy solutions including stand-alone systems and mini-grids are playing a steadily growing role in expanding electricity access in off-grid areas and strengthening supply in already connected areas

Despite the difficult shift away from carbon-intensive energy sources the energy transition – when accompanied by an appropriate policy basket – holds huge promise for Africa:

• The energy transition under IRENA’s 1.5°C Scenario pathway predicts 6.4% higher GDP 3.5% higher economy-wide jobs and a 25.4% higher welfare index than that realised under current plans on average up to 2050
• Jobs created in the renewable energy transition will outweigh those lost by moving away from traditional energy. Every million U.S. dollars invested in renewables between 2020 – 2050 would create at least 26 job-years; for every million invested in energy efficiency at least 22 job-years would be created annually; for energy flexibility the figure is 18

For these benefits to materialise the following will be required:

• A comprehensive policy package that combines the pursuit of climate and environmental goals; economic development and jobs creation; and social equity and welfare for society as a whole
• Strong institutions international co-operation (including South- South co-operation) and considerable co-ordination at the regional level

Anion exchange membrane water electrolysis (AEMWE) has acquired substantial consideration as a cost-effective hydrogen production technology. The anion ionomer content in the catalyst layers during hydrogen and oxygen evolution reaction (HER and OER) is of ultimate significance. Herein an in-situ half-cell analysis with reference electrodes was carried out for simultaneous potential measurements and identification of the influence of the anion exchange ionomer (AEI) content on anode and cathode performance. The measured half-cell potentials proved the influence of AEI content on the catalytic activity of HER and OER which was supported by the rotating disk electrode (RDE) measurements. Cathode overpotential of Ni/C was not negligible and more affected by the AEI content than anode with the optimized AEI content of 10 wt% while NiO anode OER overpotential was independent of the AEI content. For the same AEI content PGM catalysts showed higher electroactivity than Ni-based catalysts for HER and OER and the cathode catalyst's intrinsic activity is of high importance in the AEM electrolysis operation. Post-mortem analysis by SEM mapping of both AEI and catalyst distributions on the electrode surface showed the effect of AEI loading on the catalyst morphology which could be related to the electrode performance.

The cost of storing and transporting hydrogen have been one of the main challenges for the realization of the hydrogen economy. Liquid organic hydrogen carriers (LOHC) are a promising novel solution to tackle these challenges. In this paper we compare the LOHC concept to compressed gas truck delivery and on-site production of hydrogen via water electrolysis. As a case study we consider transportation of by-product hydrogen from chlor-alkali and chlorate plants to a single industrial customer which was considered to have the greatest potential for the LOHC technology to enter the markets. The results show that the LOHC delivery chain could significantly improve the economics of long distance road transport. For economic feasibility the most critical parameters identified are the heat supply method for releasing hydrogen at the end-user site and the investment costs for LOHC reactors.

An increase in human activities and population growth have significantly increased the world’s energy demands. The major source of energy for the world today is from fossil fuels which are polluting and degrading the environment due to the emission of greenhouse gases. Hydrogen is an identified efficient energy carrier and can be obtained through renewable and non-renewable sources. An overview of renewable sources of hydrogen production which focuses on water splitting (electrolysis thermolysis and photolysis) and biomass (biological and thermochemical) mechanisms is presented in this study. The limitations associated with these mechanisms are discussed. The study also looks at some critical factors that hinders the scaling up of the hydrogen economy globally. Key among these factors are issues relating to the absence of a value chain for clean hydrogen storage and transportation of hydrogen high cost of production lack of international standards and risks in investment. The study ends with some future research recommendations for researchers to help enhance the technical efficiencies of some production mechanisms and policy direction to governments to reduce investment risks in the sector to scale the hydrogen economy up.

DFT calculations at B3LYP/6-31g(dp) with the D3 version of Grimme’s dispersion are performed to investigate the application of TM-encapsulated Mg12O12 nano-cages (TM= Mn Fe and Co) as a hydrogen storage material. The molecular dynamic (MD) calculations are utilized to examine the stability of the considered structures. TD-DFT method reveals that the TM-encapsulation converts the Mg12O12 from an ultraviolet into a visible optical active material. The adsorption energy values indicate that the Mn and Fe atoms encapsulation enhances the adsorption of H2 molecules on the Mg12O12 nano-cage. The pristine Mg12O12 and CoMg12O12 do not meet the requirements for hydrogen storage materials while the MnMg12O12 and FeMg12O12 obey the requirements. MnMg12O12 and FeMg12O12 can carry up to twelve and nine H2 molecules respectively. The hydrogen adsorption causes a redshift for the λmax value of the UV-Vis. spectra of the MnMg12O12 and FeMg12O12 nano-cages. The thermodynamic calculations show that the hydrogen storage reaction for MnMg12O12 nano-cage is a spontaneous reaction while for FeMg12O12 nano-cage is not spontaneous. The results suggested that the MnMg12O12 nano-cage may be a promising material for hydrogen storage applications.

Smart energy hubs (Smart Hubs) equipped with Vehicle-to-Grid (V2G) charging photovoltaic (PV) energy generation and hydrogen storage capabilities are an emerging technology with potential to alleviate the impact of electric vehicles (EV) on the electricity grid. Their operation however is characterised by intermittent PV energy generation as well as uncertainties in EV traffic and driver preference. These uncertainties when combined with the need to maximise their financial return while guaranteeing driver satisfaction yields a challenging decision-making problem. This paper presents a novel Monte-Carlo-based modelling and computational framework for simulating the operation of Smart Hubs — providing a means for a holistic assessment of their technical and financial viability. The framework utilises a compact and representative mathematical model accounting for power losses PV module degradation variability in EV uptake price inflation driver preference and diversity in charge points and EVs. It provides a comprehensive approach for dealing with uncertainties and dependencies in EV data while being built on an energy management algorithm that maximises revenue generation ensures driver satisfaction and preserves battery life. The energy management problem is formulated as a mixed-integer linear programming problem constituting a business case that includes an adequate V2G reward model for drivers. To demonstrate its applicability the framework was used to assess the financial viability of a fleet management site for various caps on vehicle stay at the site. From the assessment controlled charging was found to be more financially rewarding in all cases yielding between 1.7% and 3.1% more revenue than uncontrolled charging. The self-consumption of the site was found to be nearly 100% due mainly to local load shifting and dispatchable hydrogen generation. V2G injection was however negligible — suggesting its unattractiveness for sites that do not participate in the demand side response market. Overall the numerical results obtained validate the applicability of the proposed framework as a decision-support tool in the sustainable design and operation of Smart Hubs for EV charging.

Understanding the mechanism of hydrogen embrittlement (HE) of austenitic steels and developing an effective strategy to improve resistance to HE are of great concern but challenging. In this work first-principles studies were performed to investigate the HE mechanism and the improved resistance of Al-containing austenite to HE. Our results demonstrate that interstitial hydrogen atoms have different site preferences in Al-free and Al-containing austenites. The calculated binding energies and diffusion barriers of interstitial hydrogen atoms in Al-containing austenite are remarkably higher than those in Al-free austenite indicating that the presence of Al is more favorable for reducing hydrogen mobility. In Al-free austenite interstitial hydrogen atoms caused a remarkable increase in lattice compressive stress and a distinct decrease in bulk shear and Young’s moduli. Whereas in Al-containing austenite the lattice compressive stress and the mechanical deterioration induced by interstitial hydrogen atoms were effectively suppressed.

Hydrogen embrittlement (HE) of metals has remained a mystery in materials science for more than a century. To try to clarify this mystery tensile tests were conducted at room temperature (RT) on a 316 stainless steel (SS) in air and hydrogen of 70 MPa. With an aim to directly observe the effect of hydrogen on ordering of 316 SS during deformation electron diffraction patterns and images were obtained from thin foils made by a focused ion beam from the fracture surfaces of the tensile specimens. To prove lattice contraction by ordering a 40% CW 316 SS specimen was thermally aged at 400 °C to incur ordering and its lattice contraction by ordering was determined using neutron diffraction by measuring its lattice parameters before and after aging. We demonstrate that atomic ordering is promoted by hydrogen leading to formation of short-range order and a high number of planar dislocations in the 316 SS and causing its anisotropic lattice contraction. Hence hydrogen embrittlement of metals is controlled by hydrogen-enhanced ordering during RT deformation in hydrogen. Hydrogen-enhanced ordering will cause the ordered metals to be more resistant to HE than the disordered ones which is evidenced by the previous observations where furnace-cooled metals with order are more resistant to HE than water-quenched or cold worked metals with disorder. This finding strongly supports our proposal that strain-induced martensite is a disordered phase.

Alkaline water electrolysis (AWE) is a mature hydrogen production technology and there exists a range of economic assessments for available technologies. For advanced AWEs which may be based on novel polymer-based membrane concepts it is of prime importance that development comes along with new configurations and technical and economic key process parameters for AWE that might be of interest for further economic assessments. This paper presents an advanced AWE technology referring to three different sites in Europe (Germany Austria and Spain). The focus is on financial metrics the projection of key performance parameters of advanced AWEs and further financial and tax parameters. For financial analysis from an investor’s (business) perspective a comprehensive assessment of a technology not only comprises cost analysis but also further financial analysis quantifying attractiveness and supply/market flexibility. Therefore based on cash flow (CF) analysis a comprehensible set of metrics may comprise levelised cost of energy or respectively levelized cost of hydrogen (LCH) for cost assessment net present value (NPV) for attractiveness analysis and variable cost (VC) for analysis of market flexibility. The German AWE site turns out to perform best in all three financial metrics (LCH NPV and VC). Though there are slight differences in investment cost and operation and maintenance cost projections for the three sites the major cost impact is due to the electricity cost. Although investment cost is slightly lower and labor cost is significantly lower in Spain the difference can not outweigh the higher electricity cost compared to Germany. Given the assumption that the electrolysis operators are customers directly and actively participating in power markets and based on the regulatory framework in the three countries in this special case electricity cost in Germany is lowest. However as electricity cost is profoundly influenced by political decisions as well as the implementation of economic instruments for transforming electricity systems toward sustainability it is hardly possible to further improve electricity price forecasts.

As fossil fuels continue to be extracted and used issues such as environmental pollution and energy scarcity are surfacing. For the transportation industry the best way to achieve the goal of “carbon neutrality” is to research efficient power systems and develop new alternative fuels. As the world’s largest product of chemicals ammonia is a new renewable fuel with good combustion energy. It can be used as an alternative fuel to reduce carbon emissions because of its proven production process low production and transportation costs safe storage the absence of carbon-containing compounds in its emissions and its future recyclability. This paper firstly introduces the characteristics of ammonia fuel engine and its problems; then it summarizes the effects of various ammonia-blended fuels on the combustion and emission characteristics of the engine from the combustion problem of ammonia-blended engine; then the fuel storage of ammonia-blended hydrogen is discussed the feasibility of hydrogen production instead of hydrogen storage is introduced.

Liquid hydrogen (LH2) compared to compressed gaseous hydrogen offers advantages for large-scale transport and storage of hydrogen with higher densities. Although the gas industry has good experience with LH2 only little experience is available for the new applications of LH2 as an energy carrier. Therefore the European FCH JU funded project PRESLHY conducted pre-normative research for the safe use of cryogenic LH2 in non-industrial settings. The central research consisted of a broad experimental program combined with analytical work modelling and simulations belonging to the three key phenomena of the accident chain: release and mixing ignition and combustion. The presented results improve the general understanding of the behavior of LH2 in accidents and provide some design guidelines and engineering tools for safer use of LH2. Recommendations for improvement of current international standards are derived.

This paper addresses how a global climate target may influence iron and steel production technology deployment and scrap use. A global energy system model ETSAP-TIAM was used and a Scrap Availability Assessment Model (SAAM) was developed to analyse the relation between steel demand recycling and the availability of scrap and their implications for steel production technology choices. Steel production using recycled materials has a continuous growth and is likely to be a major route for steel production in the long run. However as the global average of in-use steel stock increases up to the current average stock of the industrialised economies global steel demand keeps growing and stagnates only after 2050. Due to high steel demand levels and scarcity of scrap more than 50% of the steel production in 2050 will still have to come from virgin materials. Hydrogen-based steel production could become a major technology option for production from virgin materials particularly in a scenario where Carbon Capture and Storage (CCS) is not available. Imposing a binding climate target will shift the crude steel price to approximately 500 USD per tonne in the year 2050 provided that CCS is available. However the increased prices are induced by CO₂ prices rather than inflated production costs. It is concluded that a global climate target is not likely to influence the use of scrap whereas it shall have an impact on the price of scrap. Finally the results indicate that energy efficiency improvements of current processes will only be sufficient to meet the climate target in combination with CCS. New innovative techniques with lower climate impact will be vital for mitigating climate change.

The hydrogen economy refers to an economic and industrial structure that uses hydrogen as its main energy source replacing traditional fossil-fuel-based energy systems. In particular the widespread adoption of hydrogen fuel cell vehicles (HFCVs) is one of the key factors enabling a hydrogen economy and aggressive investment in hydrogen refuelling infrastructure is essential to make large-scale adoption of HFCVs possible. In this study we address the problem of effectively designing a hydrogen supply network for refuelling HFCVs in urban areas relatively far from a large hydrogen production site such as a petrochemical complex. In these urban areas where mass supply of hydrogen is not possible hydrogen can be supplied by reforming city gas. In this case building distributed hydrogen production bases that extract large amounts of hydrogen from liquefied petroleum gas (LPG) or compressed natural gas (CNG) and then supply hydrogen to nearby hydrogen stations may be a cost-effective option for establishing a hydrogen refuelling infrastructure in the early stage of the hydrogen economy. Therefore an optimization model is proposed for effectively deciding when and where to build hydrogen production bases and hydrogen refuelling stations in an urban area. Then a case study of the southeastern area of Seoul known as a commercial and residential center is discussed. A variety of scenarios for the design parameters of the hydrogen supply network are analyzed based on the target of the adoption of HFCVs in Seoul by 2030. The proposed optimization model can be effectively used for determining the time and sites for building hydrogen production bases and hydrogen refuelling stations.

The dislocation and twinning evolution behaviors in high manganese steels Fe-22Mn-0.6C and Fe-17Mn-1.5Al-0.6C have been investigated under tensile deformation with and without diffusive hydrogen. The notched tensile tests were interrupted once primary cracks were detected using the applied direct current potential drop measurement. In parallel the strain distribution in the vicinity of the crack was characterized by digital image correlation using GOM optical system. The microstructure surrounding the crack was investigated by electron backscatter diffraction. Electron channeling contrast imaging was applied to reveal the evolution of dislocations stacking faults and deformation twins with respect to the developed strain gradient and amount of hydrogen. The results show that the diffusive hydrogen at the level of 26 ppm has a conspicuous effect on initiating stacking faults twin bundles and activating multiple deformation twinning systems in Fe-22Mn-0.6C. Eventually the interactions between deformation twins and grain boundaries lead to grain boundary decohesion in this material. In comparison hydrogen does not obviously affect the microstructure evolution namely the twinning thickness and the amount of activated twinning systems in Fe-17Mn-1.5Al-0.6C. The Al-alloyed grade reveals a postponed nucleation of deformation twins delayed onset of the secondary twinning system and develops finer twinning lamellae in comparison to the Al-free material. These observations explain the improved resistance to hydrogen-induced cracking in Al-alloyed TWIP steels.

The use of hydrogen as energy carrier is a promising option to decarbonize both energy and transport sectors. This paper presents an advanced techno-economic model for calculation of optimal dispatch of large-scale multi MW electrolysis plants in order to obtain a more accurate evaluation of the feasibility of business cases related to the supply of this fuel for different end uses combined with grid services' provision. The model is applied to the Spanish case using different scenarios to determine the minimum demand required from the FCEV market so that electrolysis facilities featuring several MW result in profitable business cases. The results show that grid services contribute to the profitability of hydrogen production for mobility given a minimum but considerable demand from FCEV fleets.

Solid oxide fuel cells (SOFCs) produce electricity with high electrical efficiency and fuel flexibility without pollution for example CO₂ NO_x SO_x and particles. Still numerous issues hindered the large‐scale commercialization of fuel cell at a large scale such as fuel storage mechanical failure catalytic degradation electrode poisoning from fuel and air for example lifetime in relation to cost. Computational fluid dynamics (CFD) couples various physical fields which is vital to reduce the redundant workload required for SOFC development. Modeling of SOFCs includes the coupling of charge transfer electrochemical reactions fluid flow energy transport and species transport. The Butler‐Volmer equation is frequently used to describe the coupling of electrochemical reactions with current density. The most frequently used is the activation‐ and diffusion‐controlled Butler‐Volmer equation. Three different electrode reaction models are examined in the study which is named case 1 case 2 and case 3 respectively. Case 1 is activation controlled while cases 2 and 3 are diffusion‐controlled which take the concentration of redox species into account. It is shown that case 1 gives the highest reaction rate followed by case 2 and case 3. Case 3 gives the lowest reaction rate and thus has a much lower current density and temperature. The change of activation overpotential does not follow the change of current density and temperature at the interface of the anode and electrolyte and interface of cathode and electrolyte which demonstrates the non‐linearity of the model. This study provides a reference to build electrochemical models of SOFCs and gives a deep understanding of the involved electrochemistry.

In the transition to a climate neutral future the transportation sector needs to be sustainably decarbonized. Producing advanced fuels (such as biomethane) and bio-based valorised products (such as pyrochar) may offer a solution to significantly reduce greenhouse gas (GHG) emissions associated with energy and agricultural circular economy systems. Biological and thermochemical bioenergy technologies together with power to gas (P2G) systems can generate green renewable gas which is essential to reduce the GHG footprint of industry. However each technology faces challenges with respect to sustainability and conversion efficiency. Here this study identifies an optimal pathway leading to a sustainable bioenergy system where the carbon released in the fuel is offset by the GHG savings of the circular bio-based system. It provides a state-of-the-art review of individual technologies and proposes a bespoke circular cascading bio-based system with anaerobic digestion as the key platform integrating electro-fuels via P2G systems and value-added pyrochar via pyrolysis of solid digestate. The mass and energy analysis suggests that a reduction of 11% in digestate mass flow with the production of pyrochar bio-oil and syngas and an increase of 70% in biomethane production with the utilization of curtailed or constrained electricity can be achieved in the proposed bio-based system enabling a 70% increase in net energy output as compared with a conventional biomethane system. However the carbon footprint of the electricity from which the hydrogen is sourced is shown to be a critical parameter in assessing the GHG balance of the bespoke system.

Frontier Economics has been engaged by the Commonwealth Department of the Environment and Energy (now Industry Science Energy and Resources) (the Department) to undertake an indicative analysis of the economics of blending hydrogen in Australian natural gas distribution networks. Our analysis is limited to a specific gas distribution network servicing urban areas of Melbourne.

We have investigated the economics of blending hydrogen in a natural gas distribution network by examining a number of energy supply options including options that involve blending hydrogen. While we consider that these cases we have examined are useful for understanding the economics of hydrogen blending at low rates in Victoria and for understanding the factors that are likely to drive the economics of blending at higher rates or in other regions it cannot be assumed that the results we find for the cases we investigate will necessarily apply in other regions or for blending at other rates. This report should be read as an assessment of the specific cases we have investigated and our findings cannot necessarily be extended to other cases (such as other locations or other rates of blending)"

The full report can be found via the website of the Australian government at this link

Heat is one of the UK’s largest energy-consuming and carbon-emitting sectors and potentially the most difficult to decarbonise. The UK’s Clean Growth Strategy identifies that heat decarbonisation in buildings and industry will likely involve shifting away from natural gas to alternative energy vectors like electricity and hydrogen. This will mean transition of existing cooking appliances away from natural gas resulting in social implications that require detailed analysis for optimal transition.

This report investigates the social dimensions of heat decarbonisation in cooking appliances specifically moving away from gas cookers and hobs. It presents a first step in tackling the following questions.

• How are current carbon-intensive cooking technologies part of existing cooking practices and broader social and material structures?
• What are the challenges and opportunities for cooking heat decarbonisation in terms of consumer acceptance carbon and energy reductions and business/market opportunities?
• What interventions are needed to realise policy objectives of heat de-carbonisation?
• The report builds on interviews with BEIS’s long-term heat strategy experts and key external stakeholders together with a review of secondary data on trends in cooking and appliance use in the UK. Further it presents an annotated bibliography of literature on the social implications of heat decarbonisation and sustainable food transitions more broadly. The multidisciplinary review of the literature is structured around Southerton et al.’s (2011) ISM (Individual- Social- and Material-context) framework for a systemic review of the various change-agents required for transition. Finally a comparative review of the social challenges and opportunities identified in the ISM contexts is presented along with the potential policy interventions in each. The report concludes with a list of recommendations in terms of evidence and data gathering; research; policy; and a set of general recommendations for heat decarbonisation policy.

There is a need for alternative marine fuels in order to reduce the environmental and climate impacts of shipping in the short and long term. This study assesses the prospects for seven alternative fuels for the shipping sector in 2030 including biofuels by applying a multi-criteria decision analysis approach that is based on the estimated fuel performance and on input from a panel of maritime stakeholders and by considering explicitly the influence of stakeholder preferences. Seven alternative marine fuels—liquefied natural gas (LNG) liquefied biogas (LBG) methanol from natural gas renewable methanol hydrogen for fuel cells produced from (i) natural gas or (ii) electrolysis based on renewable electricity and hydrotreated vegetable oil (HVO)—and heavy fuel oil (HFO) as benchmark are included and ranked by ten performance criteria and their relative importance. The criteria cover economic environmental technical and social aspects. Stakeholder group preferences (i.e. the relative importance groups assign to the criteria) influence the ranking of these options. For ship-owners fuel producers and engine manufacturers economic criteria in particular the fuel price are the most important. These groups rank LNG and HFO the highest followed by fossil methanol and then various biofuels (LBG renewable methanol and HVO). Meanwhile representatives from Swedish government authorities prioritize environmental criteria specifically GHG emissions and social criteria specifically the potential to meet regulations ranking renewable hydrogen the highest followed by renewable methanol and then HVO. Policy initiatives are needed to promote the introduction of renewable marine fuels.

The Swedish steel industry stands before a potential transition to drastically lower its CO₂ emissions using direct hydrogen reduction instead of continuing with coke-based blast furnaces. Previous studies have identified hydrogen direct reduction as a promising option. We build upon earlier efforts by performing a technological innovation system study to systematically examine the barriers to a transition to hydrogen direct reduction and by providing deepened quantitative empirics to support the analysis. We also add extended paper and patent analysis methodology which is particularly useful for identifying actors and their interactions in a technological system. We conclude that while the innovation system is currently focused on such a transition notable barriers remain particularly in coordination of the surrounding technical infrastructure and the issue of maintaining legitimacy for such a transition in the likely event that policies to address cost pressures will be required to support this development.

Recently hot stamping technology has been increasingly used in automotive structural parts with ultrahigh strength to meet the standards of both high fuel efficiency and crashworthiness. However one issue of concern regarding these martensitic steels which are fabricated using a hot stamping procedure is that the steel is highly vulnerable to hydrogen delayed cracking caused by the diffusible hydrogen flow through the surface reaction of the coating in a furnace atmosphere. One way to make progress in understanding hydrogen delayed fractures is to elucidate an interaction for desorption with diffusible hydrogen behavior. The role of diffusible hydrogen on delayed fractures was studied for different baking times and temperatures in a range of automotive processes for hot-stamped martensitic steel with aluminum- and silicon-coated surfaces. It was clear that the release of diffusible hydrogen is effective at higher temperatures and longer times making the steel less susceptible to hydrogen delayed fractures. Using thermal desorption spectroscopy the phenomenon of the hydrogen delayed fracture was attributed to reversible hydrogen in microstructure sites with low trapping energy.

The objective of this project is to take into account the mechanical constraints formed by diffusion of hydrogen or tritium in watertight palladium alloy cathode. To know the origin of these it was necessary to discriminating the damaging effects encountered. Effectively hydrogen and isotope induce deformation embrittlement stress corrosion cracking and cathodic corrosion in different regions of cathode. Palladium can be alloyed with silver or yttrium to favourably increase diffusion and reduce these constraints. Effects of electrochemical factors temperature cathode structure adsorbed transient complex of palladium and porous material support are given to estimate and to limit possible damage.

In a future fossil-free circular economy the petroleum-based plastics industry must be converted to non-fossil feedstock. A known alternative is bio-based plastics but a relatively unexplored option is deriving the key plastic building blocks hydrogen and carbon from electricity through electrolytic processes combined with carbon capture and utilization technology. In this paper the future demand for electricity and carbon dioxide is calculated under the assumption that all plastic production is electricity-based in the EU by 2050. The two most important input chemicals are ethylene and propylene and the key finding of this paper is that the electricity demand to produce these are estimated to 20 MWh/ton ethylene and 38 MWh/ton propylene and that they both could require about 3 tons of carbon dioxide/ton product. With constant production levels this implies an annual demand of about 800 TWh of electricity and 90 Mton of carbon dioxide by 2050 in the EU. If scaled to the total production of plastics including all input hydrocarbons in the EU the annual demand is estimated to 1600 TWh of electricity and 180 Mton of carbon dioxide. This suggests that a complete shift to electricity-based plastics is possible from a resource and technology point of view but production costs may be 2 to 3 times higher than today. However the long time frame of this paper creates uncertainties regarding the results and how technical economic and social development may influence them. The conclusion of this paper is that electricity-based plastics integrated with bio-based production can be an important option in 2050 since biomass resources are scarce but electricity from renewable sources is abundant.

Synthetic natural gas (SNG) is one of the promising energy carriers for the excessive electricity generated from variable renewable energy sources. SNG production from renewable H₂ and CO₂  via catalytic CO₂ methanation has gained much attention since CO₂ emissions could be simultaneously reduced. In this study Ni–Fe/(MgAl)O_x alloy catalysts for CO₂ methanation were prepared via hydrotalcite precursors using a rapid coprecipitation method. The effect of total metal concentration on the physicochemical properties and catalytic behavior was investigated. Upon calcination the catalysts showed high specific surface area of above 230 m² g⁻¹. Small particle sizes of about 5 nm were obtained for all catalysts even though the produced catalyst amount was increased by 10 times. The catalysts exhibited excellent space-time yield under very high gas space velocity (34000 h⁻¹) irrespective of the metal concentration. The CO₂ conversions reached 73–79% at 300 °C and CH₄ selectivities were at 93–95%. Therefore we demonstrated the potential of large-scale production of earth-abundant Ni–Fe based catalysts for CO₂ methanation and the Power-to-Gas technology.

Plastic pre-strains were applied to the metastable 304L austenitic stainless steel at both room temperature (20 °C) and higher temperatures (i.e. 50 80 and 100 °C) and then the hydrogen embrittlement (HE) susceptibility of the steel was evaluated by cathodically hydrogen-charging and tensile testing. The 20 °C pre-strain greatly strengthened the steel but simultaneously significantly increased the HE susceptibility of the steel since α′ martensite was induced by the pre-strain causing the pre-existence of α′ martensite which provided “highways” for hydrogen to transport deep into the steel during the hydrogen-charging. Although the warm pre-strains did not strengthen the steel as significantly as the 20 °C pre-strain they retained the HE resistance of the steel. This is because the higher temperatures particularly 80 and 100 °C suppressed the α′ martensite transformation during the pre-straining. Pre-strain at a temperature slightly higher than room temperature has a potential to strengthen the metastable 304L austenitic stainless steel without compromising its initial HE resistance.

Interest in hydrogen as a carbon-neutral energy carrier is on the rise around the globe including in Europe. In particular power-to-gas as a technology to transform electricity to hydrogen is receiving ample attention. This article scrutinises current updates in the energy law framework of the EU to explain the legal pre-conditions for the various possible applications of power-to-gas technology. It highlights the influence of both electricity and gas legislation on conversion storage and transmission of hydrogen and demonstrates why ‘green’ hydrogen might come with certain legal privileges under the Renewable Energy Directive attached to it as opposed to the European Commission’s so-called ‘clean’ hydrogen. The article concludes by advocating for legal system integration in EU energy law namely merging the currently distinct EU electricity and gas law frameworks into one unified EU Energy Act.

Taiwan stands out globally in the manufacture of scooters. If fuel cell technology could be applied to the scooter Taiwan could gain an advantage in the trend for commercial applications for fct. In 2011 The Bureau of Standards Metrology and Inspection proposed this project “the Demonstration of Hydrogen Fuel Cell Scooters.” Thirty rental fuel cell scooters are to run a long distance. Evaluation during everyday use of the cells performance will be made and reported by the riders. All the evaluations will be put into consideration of future adjustments. The project is to map out a practice route in Taipei and set up a control center to follow progress. The data gathered from the practice project will help examine the performance of fuel cell scooters contributing to the creation of legal drafts and future standards. The Taiwan fuel cell industry chain is complete and the industry possesses the ability to produce key components. Thus it is a potential market in Taiwan. A review of fuel cell development conditions in Taiwan shows that the fuel cell scooters is a niche industry owing to the strength of this technology.

The presence of a conductive layers of hot-formed oxide on the surface of bars for pre or post-compressing structures can promote localized attacks as a function of pH. The aggressive local environment in the occluded cells inside localized attacks has as consequence the possibility of initiation of stress corrosion cracking. In this paper the stress corrosion cracking behavior of high strength steels proposed for tendons was studied by means of Constant Load (CL) tests and Slow Strain Rate (SSR) tests. Critical ranges of pH for cracking were verified. The promoting role of localized attack was confirmed. Further electrochemical tests were performed on bars in as received surface conditions in order to evaluate pitting initiation. The adverse effect of mill scale was recognized.

The report documents current knowledge of the social issues surrounding hydrogen projects. It reviews leading practice stakeholder engagement and communication strategies and findings from focus groups and research activities across Australia.

The full report can be found at this link.

Deployed at scale hydrogen could account for almost one-fifth of total final energy consumed by 2050. This would reduce annual CO2 emissions by roughly 6 gigatons compared to today’s levels and contribute roughly 20% of the abatement required to limit global warming to two degrees Celsius.

On the demand side the Hydrogen Council sees the potential for hydrogen to power about 10 to 15 million cars and 500000 trucks by 2030 with many uses in other sectors as well such as industry processes and feedstocks building heating and power power generation and storage. Overall the study predicts that the annual demand for hydrogen could increase tenfold by 2050 to almost 80 EJ in 2050 meeting 18% of total final energy demand in the 2050 two-degree scenario. At a time when global populations are expected to grow by two billion people by 2050 hydrogen technologies have the potential to create opportunities for sustainable economic growth.

“The world in the 21st century must transition to widespread low carbon energy use” said Takeshi Uchiyamada Chairman of Toyota Motor Corporation and co-chair of the Hydrogen Council. “Hydrogen is an indispensable resource to achieve this transition because it can be used to store and transport wind solar and other renewable electricity to power transportation and many other things. The Hydrogen Council has identified seven roles for hydrogen which is why we are encouraging governments and investors to give it a prominent role in their energy plans. The sooner we get the hydrogen economy going the better and we are all committed to making this a reality.”

Achieving such scale would require substantial investments; approximately US$20 to 25 billion annually for a total of about US$280 billion until 2030. Within the right regulatory framework – including long-term stable coordination and incentive policies – the report considers that attracting these investments to scale the technology is feasible. The world already invests more than US$1.7 trillion in energy each year including US$650 billion in oil and gas US$300 billion in renewable electricity and more than US$300 billion in the automotive industry.

“This study confirms the place of hydrogen as a central pillar in the energy transition and encourages us in our support of its large-scale deployment. Hydrogen will be an unavoidable enabler for the energy transition in certain sectors and geographies. The sooner we make this happen the sooner we will be able to enjoy the needed benefits of Hydrogen at the service of our economies and our societies” said Benoît Potier Chairman and CEO Air Liquide. “Solutions are technologically mature and industry players are committed. We need concerted stakeholder efforts to make this happen; leading this effort is the role of the Hydrogen Council.”

The launch of the new roadmap came during the Sustainability Innovation Forum in the presence of 18 senior members of the Hydrogen led by co-chairs Takeshi Uchiyamada Chairman of Toyota and Benoît Potier Chairman and CEO Air Liquide and accompanied by Prof. Aldo Belloni CEO of The Linde Group Woong-chul Yang Vice Chairman of Hyundai Motor Company and Anne Stevens Board Member of Anglo American. During the launch the Hydrogen Council called upon investors policymakers and businesses to join them in accelerating deployment of hydrogen solutions for the energy transition. It was also announced that Woong-chul Yang of Hyundai Motor Company will succeed Takeshi Uchiyamada of Toyota in the rotating role of the Council’s co-chair and preside the group together with Benoit Potier CEO Air Liquide in 2018. Mr Uchiyamada is planning to return as Co-chairman in 2020 coinciding with the Tokyo Olympic and Paalympic Games an important milestone for showcasing hydrogen society and mobility.

You can download the full report from the Hydrogen Council website here

There is significant interest in Australia both federally and at the state level to develop a hydrogen production industry. Australia’s Chief Scientist Alan Finkel recently prepared a briefing paper for the COAG Energy Council outlining a road map for hydrogen. It identifies hydrogen has the potential to be a significant source of export revenue for Australia in future years assist with decarbonising Australia’s economy and could establish Australia as a leader in low emission fuel production.

As part of the ongoing investigations into the hydrogen production potential of Australia Geoscience Australia has been commissioned by the Department of Industry Innovation and Science to develop heat maps that show areas with high potential for future hydrogen production. The study is technology agnostic in that it considers hydrogen production via electrolysis using renewable energy sources and also fossil fuel hydrogen coupled with carbon capture and storage (CCS). The heat maps presented in this work are synthesized from the key individual national-scale datasets that are relevant for hydrogen production. In the case of hydrogen from electrolysis renewable energy potential and the availability of water are the most important factors with various infrastructural considerations playing a secondary role. In the case of fossil fuel hydrogen proximity to gas and coal resources water and availability of carbon storage sites are the important parameters that control the heat maps. In this report we present 5 different heat map scenarios reflecting different assumptions in the geospatial analysis and also reflecting to some degree the different projected timeframes for hydrogen production. The first three scenarios pertain to renewable energy and hydrogen There is significant interest in Australia both federally and at the state level to develop a hydrogen production industry. In August 2018 Australia’s Chief Scientist Dr Alan Finkel prepared a briefing paper for the COAG Energy Council outlining a road map for hydrogen. It identifies hydrogen has the potential to be a significant source of export revenue for Australia in future years assist with decarbonising Australia’s economy and could establish Australia as a leader in low emission fuel production.

As part of ongoing investigations into the hydrogen production potential of Australia Geoscience Australia has been engaged by the Department of Industry Innovation and Science to develop maps that show areas with high potential for future hydrogen production. The study is technology agnostic but considers only low carbon production processes. It includes hydrogen production via electrolysis using renewable energy sources (referred to as renewable hydrogen) as well as fossil fuel-derived hydrogen coupled with carbon capture and storage (CCS) (referred to as CCS hydrogen). The maps presented in this work are synthesized from the key individual national-scale datasets that are relevant for hydrogen production. In the case of hydrogen from electrolysis renewable energy potential (from wind solar and hydro resources) and the availability of water are the most important factors while various infrastructure considerations also play a role. In the case of CCS hydrogen proximity to gas and coal resources water and availability of carbon storage sites are the important parameters that control the spatial distribution of potential hydrogen production. In this report we present five different scenarios that reflect key differences in technologies for hydrogen production and the requirements of those technologies. Using geospatial analysis each scenario is translated into a heat map that shows regional trends in potential for hydrogen production based on access to underpinning resources and existing infrastructure.

Three scenarios explore the future potential for renewable hydrogen produced by electrolysis. These demonstrate a high potential for hydrogen production in the future near many Australian coastal areas which is even larger if infrastructure is available to transport renewable power generated from inland areas to the coast. Results also show significant future potential for hydrogen production in inland areas where water is available. The final two scenarios focus on the future potential for CCS hydrogen: a 2030 scenario and a 2050 scenario. A key factor in future CCS hydrogen potential is related to the timeframes for the availability of geological storage resources for CO_2.

This policy statement provides:

An overview of our key priorities for the short to medium-term and then moves on to look at how we have continued to abide by the three key principles set out in Scotland's Energy Strategy published in 2017 in our policy design and delivery. Those principles are:

• a whole-system view;
• an inclusive energy transition; and
• a smarter local energy model.

An overview of how we have committed to ensuring a green economic recovery in respect of energy while remaining aligned to our net zero ambitions. We have set these out under the following themes to align with our wider green recovery narrative in the Programme for Government

• Skills and Jobs;
• Supporting Local Communities:
• Investment; and
• Innovation

along with some specific policy examples.



Separate sections have been included on Maximising Scotland's International Potential in the lead up to the UN Framework Convention on Climate Change Conference of the Parties (COP26) and on Consumers to reflect the challenging economic climate we currently face and to highlight the action being taken by the Scottish Government to ensure the cost of our energy transition does not fall unequally.



This statement provides an overview of our approach to supporting the energy sector in the lead up to COP26 and as we embark on a green economic recovery from the COVID-19 pandemic. It summarises how our recent policy publications such as our Hydrogen Policy Statement Local Energy Policy Statement and Offshore Wind Policy Statement collectively support the delivery of the Climate Change Plan update along with the future findings from our currently live consultations including our draft Heat in Buildings Strategy our Call for Evidence on the future development of the Low Carbon Infrastructure Transition Programme (LCITP) and our consultation on Scottish skills requirements for energy efficiency.



While this statement sets out our comprehensive programme of work across the energy sector the current Energy Strategy (2017) remains in place until any further Energy Strategy refresh is adopted by Ministers. It is at the stage of refreshing Scotland's Energy Strategy where we will embark on a series of stakeholder engagements and carry out the relevant impact assessments to inform our thinking on future policy development.

Structural integrity of reactor pressure vessel (RPV) in light water reactors (LWR) is of highest importance regarding operation safety and lifetime. The fracture behaviour of low-alloy RPV steels with different dynamic strain aging (DSA) & environmental assisted cracking (EAC) susceptibilities in simulated LWR environments was evaluated by elastic plastic fracture mechanics tests (EPFM) and by metallo- and fractographic post-test analysis. Exposure to high temperature water (HTW) environments at LWR temperatures revealed only moderated reductions in the fracture initiation and tearing resistance of low alloy RPV steels with high DSA or EAC susceptibility accompanied with a moderate but clear change in fracture morphology which indicates the potential synergies of hydrogen/HTW embrittlement with DSA and EAC under suitable conditions. The most pronounced degradation effects occurred in a) RPV steels with high DSA susceptibility where the fracture initiation and tearing resistance reduction increased with decreasing loading rate and were most pronounced in hydrogenated HTW and b) high sulphur steels with high EAC susceptibility in aggressive occluded crevice environment and with preceding fast EAC crack growth in oxygenated HTW. The moderate effects are due to the low hydrogen availability in HTW together with high density of fine-dispersed hydrogen traps in RPV steels. Stable ductile transgranular tearing by microvoid coalescence was the dominant failure mechanism in all environments with additional varying few % of secondary cracks macrovoids and quasi-cleavage in HTW. The observed behavior suggests a combination of plastic strain localisation by the Hydrogen-enhanced Local Plasticity (HELP) mechanism in synergy with DSA and Hydrogen-enhanced Strain-induced Vacancies (HESIV) mechanism with additional minor contributions of Hydrogen-enhanced Decohesion Embrittlement (HEDE) mechanism.

Fuel cells are the most clean and efficient power source for vehicles. In particular proton exchange membrane fuel cells (PEMFCs) are the most promising candidate for automobile applications due to their rapid start-up and low-temperature operation. Through extensive global research efforts in the latest decade the performance of PEMFCs including energy efficiency volumetric and mass power density and low temperature startup ability have achieved significant breakthroughs. In 2014 fuel cell powered vehicles were introduced into the market by several prominent vehicle companies. However the low durability and high cost of PEMFC systems are still the main obstacles for large-scale industrialization of this technology. The key materials and components used in PEMFCs greatly affect their durability and cost. In this review the technical progress of key materials and components for PEMFCs has been summarized and critically discussed including topics such as the membrane catalyst layer gas diffusion layer and bipolar plate. The development of high-durability processing technologies is also introduced. Finally this review is concluded with personal perspectives on the future research directions of this area.

Alloying and structural modification are two effective ways to enhance the hydrogen storage kinetics and decrease the thermal stability of Mg and Mg-based alloys. In order to enhance the characteristics of Mg₂Ni-type alloys Cu and La were added to an Mg₂Ni-type alloy and the sample alloys (Mg₂₄Ni₁₀Cu₂)_100−xLa_x (x = 0 5 10 15 20) were prepared by melt spinning. The influences of La content and spinning rate on the gaseous and electrochemical hydrogen storage properties of the sample alloys were explored in detail. The structural identification carried out by XRD and TEM indicates that the main phase of the alloys is Mg₂Ni and the addition of La results in the formation of the secondary phases LaMg₃ and La₂Mg₁₇. The as-spun alloys have amorphous and nanocrystalline structures and the addition of La promotes glass formation. The electrochemical properties examined by an automatic galvanostatic system show that the samples possess a good activation capability and achieve their maximal discharge capacities within three cycles. The discharge potential characteristics were vastly ameliorated by melt spinning and La addition. The discharge capacities of the samples achieve their maximal values as the La content changes and the discharge capacities always increase with increasing spinning rate. The addition of La leads to a decline in hydrogen absorption capacity but it can effectively enhance the rate of hydrogen absorption. The addition of La and melt spinning significantly increase the hydrogen desorption rate due to the reduced activation energy.

Recent advances on synthesis characterization and hydrogen absorption properties of ultrasmall metal nanoparticles (defined here as objects with average size ≤3 nm) are briefly reviewed in the first part of this work. The experimental challenges encountered in performing accurate measurements of hydrogen absorption in Mg- and noble metal-based ultrasmall nanoparticles are addressed. The second part of this work reports original results obtained for ultrasmall bulk-immiscible Pd–Rh nanoparticles. Carbon-supported Pd–Rh nanoalloys in the whole binary chemical composition range have been successfully prepared by liquid impregnation method followed by reduction at 300°C. EXAFS investigations suggested that the local structure of these nanoalloys is partially segregated into Rh-rich core and Pd-rich surface coexisting within the same nanoparticles. Downsizing to ultrasmall dimensions completely suppresses the hydride formation in Pd-rich nanoalloys at ambient conditions contrary to bulk and larger nanosized (5–6 nm) counterparts. The ultrasmall Pd90Rh10 nanoalloy can absorb hydrogen-forming solid solutions under these conditions as suggested by in situ X-ray diffraction (XRD). Apart from this composition common laboratory techniques such as in situ XRD DSC and PCI failed to clarify the hydrogen interaction mechanism: either adsorption on developed surfaces or both adsorption and absorption with formation of solid solutions. Concluding insights were brought by in situ EXAFS experiments at synchrotron: ultrasmall Pd₇₅Rh₂₅ and Pd₅₀Rh₅₀ nanoalloys absorb hydrogen-forming solid solutions at ambient conditions. Moreover the hydrogen solubility in these solid solutions is higher with increasing Pd content and this trend can be understood in terms of hydrogen preferential occupation in the Pd-rich regions as suggested by in situ EXAFS. The Rh-rich nanoalloys (Pd₂₅Rh₇₅ and Pd₁₀Rh₉₀) only adsorb hydrogen on the developed surface of ultrasmall nanoparticles. In summary in situ characterization techniques carried out at large-scale facilities are unique and powerful tools for in-depth investigation of hydrogen interaction with ultrasmall nanoparticles at local level.

Chemical looping water splitting or chemical looping hydrogen is a very promising technology for the production of hydrogen. In recent years extensive research has enabled remarkable leaps towards a successful integration of the chemical looping technology into a future hydrogen infrastructure. Progress has been reported with iron based oxygen carriers for stable hydrogen production capacity over consecutive cycles without significant signs of degradation. The high stability improvements were achieved by adding alien metal oxides or by integrating the active component into a mineral structure which offers excellent resistance towards thermal stress. Prototype systems from small μ-systems up to 50 kW have been operated with promising results. The chemical looping water splitting process was broadened in terms of its application area and utilization of feedstocks using a variety of renewable and fossil resources. The three-reactor system was clearly advantageous due to its flexibility heat integration capabilities and possibility to produce separate pure streams of hydrogen CO₂ and N₂. However two-reactor and single fixed-bed reactor systems were successfully operated as well. This review aims to survey the recently presented literature in detail and systematically summarize the gathered data.