Publications

Using electricity for heating can contribute to decarbonization and provide flexibility to integrate variable renewable energy. We analyze the case of electric storage heaters in German 2030 scenarios with an open-source electricity sector model. We find that flexible electric heaters generally increase the use of generation technologies with low variable costs which are not necessarily renewables. Yet making customary night-time storage heaters temporally more flexible offers only moderate benefits because renewable availability during daytime is limited in the heating season. Respective investment costs accordingly have to be very low in order to realize total system cost benefits. As storage heaters feature only short-term heat storage they also cannot reconcile the seasonal mismatch of heat demand in winter and high renewable availability in summer. Future research should evaluate the benefits of longer-term heat storage.

The increasing feed-in of intermittent renewable energy sources into the electricity grids worldwide is currently leading to technical challenges. Stationary energy storage systems provide a cost-effective and efficient solution in order to facilitate the growing penetration of renewable energy sources. Major technical and economical challenges for energy storage systems are related to lifetime efficiency and monetary returns. Holistic simulation tools are needed in order to address these challenges before investing in energy storage systems. One of these tools is SimSES a holistic simulation framework specialized in evaluating energy storage technologies technically and economically. With a modular approach SimSES covers various topologies system components and storage technologies embedded in an energy storage application. This contribution shows the capabilities and benefits of SimSES by providing in-depth knowledge of the implementations and models. Selected functionalities are demonstrated with two use cases showing the easy-to-use simulation framework while providing detailed technical analysis for expert users. Hybrid energy storage systems consisting of lithium-ion and redox-flow batteries are investigated in a peak shaving application while various system topologies are analyzed in a frequency containment reserve application. The results for the peak shaving case study show a benefit in favor of the hybrid system in terms of overall cost and degradation behavior in applications that have a comparatively low energy throughput during lifetime. In terms of system topology a cascaded converter approach shows significant improvements in efficiency for the frequency containment reserve application.

The percentage of the population in urban areas has increased by ten points from 2000 (46%) to 2020 (56%); it is expected to reach up to 70% by 2050. This undoubtedly will encourage society to use alternative transports. On the other hand the widespread fear of pandemics seems to be here to stay and it is causing most people to leave public transport to use private cars and a few have chosen unipersonal electric vehicles. As a consequence the decision of using private cars negatively affects the air quality and consequently urban population health. This paper aims to demonstrate a sustainable solution for urban mobility based on a hydrogen powered unipersonal electric vehicle which as shown provides great advantages over the conventional battery powered unipersonal electric vehicle. To show this the authors have developed both vehicles in comparable versions using the same platform and ensuring that the total weight of the unipersonal electric vehicle was the same in both cases. They have been subjected to experimental tests that support the features of the hydrogen-based configuration versus the battery-based one including higher specific energy more autonomy and shorter recharge time.

The unique layered morphology of van der Waals (vdW) heterostructures give rise to a blended set of electrochemical properties from the 2D sheet components. Herein an overview of their potential in energy storage systems in place of precious metals is conducted. The most recent progress on vdW electrocatalysis covering the last three years of research is evaluated with an emphasis on their catalytic activity towards the oxygen reduction reaction (ORR) oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). This analysis is conducted in pair with the most active Pt-based commercial catalyst currently utilized in energy systems that rely on the above-listed electrochemistry (metal–air battery fuel cells and water electrolyzers). Based on current progress in HER catalysis that employs vdW materials several recommendations can be stated. First stacking of the two types vdW materials with one being graphene or its doped derivatives results in significantly improved HER activity. The second important recommendation is to take advantage of an electronic coupling when stacking 2D materials with the metallic surface. This significantly reduces the face-to-face contact resistance and thus improves the electron transfer from the metallic surface to the vdW catalytic plane. A dual advantage can be achieved from combining the vdW heterostructure with metals containing an excess of d electrons (e.g. gold). Despite these recent and promising discoveries more studies are needed to solve the complexity of the mechanism of HER reaction in particular with respect to the electron coupling effects (metal/vdW combinations). In addition more affordable synthetic pathways allowing for a well-controlled confined HER catalysis are emerging areas.

This paper compares the well-to-wheel (WTW) greenhouse gas (GHG) emissions of representative vehicle types–internal combustion engine vehicle (ICEV) hybrid electric vehicle (HEV) plug-in hybrid electric vehicle (PHEV) battery electric vehicle (BEV) and fuel cell electric vehicle (FCEV)–in the future (2030) based on a WTW analysis for the present (2017) and an analysis of various energy policies that could affect future emissions. South Korea was selected as the target region because it has detailed energy policies related to alternative vehicles. The WTW analysis for the present was performed based on three sets of subordinate analyses: (1) life cycle analyses of eight base fuels; (2) life cycle analyses of electricity and hydrogen; and (3) analyses of the fuel economies of seven vehicle types. From the WTW analysis for the present the national average WTW GHG emissions of ICEV-gasoline ICEV-diesel ICEV-liquefied petroleum gas HEV PHEV BEV and FCEV were calculated as 225 233 201 159 133 109 and 55 g-CO₂-eq./km respectively. For calculating the WTW GHG emissions in the future two policies regarding electricity production and three policies regarding hydrogen production were analysed. Three cases with varying the degrees of improvements in fuel economies were considered. Six future scenarios were constructed and each scenario represented the case in which each energy policy is enacted. In the reference scenario for compact car the WTW GHG emissions of ICEVs-gasoline HEV PHEV BEV-200 mile FCEV were analysed as 161 110 97 86 and 91 g-CO₂-eq./km respectively. The differences between ICEV/HEV and BEV were predicted to decrease in the future mainly due to larger improvements of ICEV/HEV in fuel economies compared to that of BEV. The future life cycle GHG emissions of electricity and hydrogen were calculated according to energy policy. Both two policies regarding power generation were confirmed to increase the benefits of utilizing BEVs but current energy policy regarding hydrogen production were confirmed to decrease the benefits of utilizing FCEVs. Based on the comprehensive results of this study a framework was proposed to evaluate the impacts of an energy policy regarding electricity and hydrogen production on the benefits of using BEVs and FCEVs compared to using HEVs and ICEVs. This framework can also be utilized in other countries when they assess and establish their energy policies.

This paper investigates environmental impacts of high pressure alkaline water electrolysis systems. An advanced system with membranes on polymer basis is compared to a state-of-the-art system with asbestos membranes using a Life Cycle Assessment (LCA) approach. For the advanced system a new improved membrane technology has been investigated within the EU research project “ELYGRID”. Results indicate that most environmental impacts are caused by the electricity supply necessary for operation. During the construction phase cell stacks are the main contributor to environmental impacts. New improved membranes have relatively small contributions to impacts caused by cell construction within the advanced systems. As main outcome the systems comparison illustrates a better ecological performance of the new developed system

The use of hydrogen as an alternative to fossil fuels for vehicle propulsion is already a reality. However due to its physical characteristics storage is still a challenge. There is an innovative way presented in this study to store hydrogen in conventional vehicles propelled by spark-ignition reciprocating engines and fuel cells using hydrogen as fuel; the storage of hydrogen will be at high pressure within small spheres randomly packed in a tank like the conventional tank of fuel used nowadays in current vehicles. Therefore the main purpose of the present study is to assess the performance of this storage system and compare it to others already applied by car manufacturers in their cars. In order to evaluate the performance of this storage system some parameters were taken into account: The energy stored by volume and stored by weight hydrogen leakage and compliance with current standards. This system is safer than conventional storage systems since hydrogen is stored inside small spheres containing small amounts of hydrogen. Besides its gravimetric energy density (GED) is threefold and the volumetric energy density (VED) is about half when compared with homologous values for conventional systems and both exceed the targets set by the U.S. Department of Energy. Regarding the leakage of hydrogen it complies with the European Standards provided a suitable choice of materials and dimensions is made.

This paper presents the results of a demonstration project including building-integrated photovoltaic (BIPV) solar panels a residential building and a hydrogen fuel cell electric vehicle (FCEV) for combined mobility and power generation aiming to achieve a net zero-energy residential building target. The experiment was conducted as part of the Car as Power Plant project at The Green Village in the Netherlands. The main objective was to assess the end-user’s potential of implementing FCEVs in vehicle-to-grid operation (FCEV2G) to act as a local energy source. FCEV2G field test performance with a Hyundai ix35 FCEV are presented. The car was adapted using a power output socket capable of delivering up to 10 kW direct current (DC) to the alternating current (AC) national grid when parked via an off-board (grid-tie) inverter. A Tank-To-AC-Grid efficiency (analogous to Tank- To-Wheel efficiency when driving) of 44% (measured on a Higher Heating Value basis) was obtained when the car was operating in vehicle-to-grid (V2G) mode at the maximum power output. By collecting and analysing real data on the FCEV power production in V2G mode and on BIPV production and household consumption two different operating modes for the FCEV offering balanced services to a residential microgrid were identified namely fixed power output and load following. Based on the data collected one-year simulations of a microgrid consisting of 10 all-electric dwellings and 5 cars with the different FCEV2G modes of operation were performed. Simulation results were evaluated on the factors of autonomy self-consumption of locally produced energy and net-energy consumption by implementing different energy indicators. The results show that utilizing an FCEV working in V2G mode can reduce the annual imported electricity from the grid by approximately 71% over one year and aiding the buildings in the microgrid to achieve a net zero-energy building target. Furthermore the simulation results show that utilizing the FCEV2G setup in both modes analysed could be economically beneficial for the end-user if hydrogen prices at the pump fall below 8.24 €/kg.

The NASA Safety Standard which establishes a uniform process for hydrogen system design materials selection operation storage and transportation is presented. The guidelines include suggestions for safely storing handling and using hydrogen in gaseous (GH2) liquid (LH2) or slush (SLH2) form whether used as a propellant or non-propellant. The handbook contains 9 chapters detailing properties and hazards facility design design of components materials compatibility detection and transportation. Chapter 10 serves as a reference and the appendices contained therein include: assessment examples; scaling laws explosions blast effects and fragmentation; codes standards and NASA directives; and relief devices along with a list of tables and figures abbreviations a glossary and an index for ease of use. The intent of the handbook is to provide enough information that it can be used alone but at the same time reference data sources that can provide much more detail if required.

In this analysis life cycle environmental burdens and total costs of ownership (TCO) of current (2017) and future (2040) passenger cars with different powertrain configurations are compared. For all vehicle configurations probability distributions are defined for all performance parameters. Using these a Monte Carlo based global sensitivity analysis is performed to determine the input parameters that contribute most to overall variability of results. To capture the systematic effects of the energy transition future electricity scenarios are deeply integrated into the ecoinvent life cycle assessment background database. With this integration not only the way how future electric vehicles are charged is captured but also how future vehicles and batteries are produced. If electricity has a life cycle carbon content similar to or better than a modern natural gas combined cycle powerplant full powertrain electrification makes sense from a climate point of view and in many cases also provides reductions in TCO. In general vehicles with smaller batteries and longer lifetime distances have the best cost and climate performance. If a very large driving range is required or clean electricity is not available hybrid powertrain and compressed natural gas vehicles are good options in terms of both costs and climate change impacts. Alternative powertrains containing large batteries or fuel cells are the most sensitive to changes in the future electricity system as their life cycles are more electricity intensive. The benefits of these alternative drivetrains are strongly linked to the success of the energy transition: the more the electricity sector is decarbonized the greater the benefit of electrifying passenger vehicles.

In this study the optimal sizing of a hybrid battery/hydrogen Energy Storage System “ESS” is assessed via a model-based parametric analysis in the context of a real hybrid renewable microgrid located in Huelva Spain supplying a real-time monitored residential load (3.5 kW; 5.6 MWh/year) in island mode. Four storage configurations (battery-only H2-only hybrid battery priority and hybrid H2 priority) are assessed under different Energy Management Strategies analysing system performance parameters such as Loss of Load “LL” (kWh;%) Over Production “OP” (kWh;%) round-trip storage efficiency ESS (%) and total storage cost (€) depending on the ESS sizing characteristics. A parallel approach to the storage optimal sizing via both multi-dimensional sensitivity analysis and PSO is carried out in order to address both sub-optimal and optimal regions respectively. Results show that a hybridised ESS capacity is beneficial from an energy security and efficiency point of view but can represent a substantial additional total cost (between 100 and 300 k€) to the hybrid energy system especially for the H2 ESS which presents higher costs. Reaching 100% supply from renewables is challenging and introducing a LL threshold induces a substantial relaxation of the sizing and cost requirements. Increase in battery capacity is more beneficial for the LL abatement while increasing H2 capacity is more useful to absorb large quantities of excess energy. The optimal design via PSO technique is complemented to the parametric study.

Rapid industrial development vehicles domestic activities and mishandling of garbage are the main sources of pollutants which are destroying the atmosphere. There is a need to continuously monitor these pollutants for the safety of the environment and human beings. Conventional instruments for monitoring of toxic gases are expensive bigger in size and time-consuming. Hybrid materials containing organic and inorganic components are considered potential candidates for diverse applications including gas sensing. Gas sensors convert the information regarding the analyte into signals. Various polymeric/inorganic nanohybrids have been used for the sensing of toxic gases. Composites of different polymeric materials like polyaniline (PANI) poly (4-styrene sulfonate) (PSS) poly (34-ethylene dioxythiophene) (PEDOT) etc. with various metal/metal oxide nanoparticles have been reported as sensing materials for gas sensors because of their unique redox features conductivity and facile operation at room temperature. Polymeric nanohybrids showed better performance because of the larger surface area of nanohybrids and the synergistic effect between polymeric and inorganic materials. This review article focuses on the recent developments of emerging polymeric/inorganic nanohybrids for sensing various toxic gases including ammonia hydrogen nitrogen dioxide carbon oxides and liquefied petroleum gas. Advantages disadvantages operating conditions and prospects of hybrid composites have also been discussed.

Gas pipelines are exposed to operational loads combined with corrosive environment action during their long-term service. Complicated service conditions lead to a worsening of steel properties a reduction of serviceability of the whole object therefore a risk of its premature failure rises. Aware of the importance of the existing problem the aim of this study is the analysis of various mechanical properties of steels after their long-term operation on gas pipelines and detecting and evaluating fractographic signs of this degradation.<br/>Mechanical properties of operated pipe steels characterizing their brittle fracture resistance were significantly decreased. Delamination areas as one of a feature of brittle fracture were identified on the fracture surfaces of specimens after SSRT of the operated steels in corrosive environment. Fracture was initiated from the outer surface of the specimens along the boundaries of ferrite and pearlite grains with significant secondary cracking.<br/>The obvious texture in the steels affects noticeably the results of the impact tests. Higher KCV values for the specimens cut in the longitudinal direction relative to the pipe axis comparing with the specimens of transversal orientation were obtained. This was explained by different length of narrow pearlite strips alternated by wide ferrite bands and interrupted by individual ferrite grains depending on the orientation of the specimen fracture surface relative to the pipe axis. Thus a proper direction of specimen cutting to achieve the maximum sensitivity of KCV parameter to operational degradation of steels is discussed. The effect of specimen orientation on the results of the Charpy testing becomes much more pronounced with steel operation. Defects accumulated in steels during their service are preferentially oriented in the pipe axial direction along the boundaries between ferrite and pearlite strips. Analyzing the fracture surfaces of the Charpy specimens after their impact testing certain signs of embrittlement were found for long term operated steels in the form of delaminations varying in size and shape and some cleavage fragments. Furthermore their percentage of total fracture surface (generally formed by dimples) correlates well with a drop in the impact toughness. The established relationship could be the basis for the introduction of fractographic criteria of the steel serviceability.

Automotive proton-exchange membrane fuel cells (PEMFCs) have finally reached a state of technological readiness where several major automotive companies are commercially leasing and selling fuel cell electric vehicles including Toyota Honda and Hyundai. These now claim vehicle speed and acceleration refueling time driving range and durability that rival conventional internal combustion engines and in most cases outperform battery electric vehicles. The residual challenges and areas of improvement which remain for PEMFCs are performance at high current density durability and cost. These are expected to be resolved over the coming decade while hydrogen infrastructure needs to become widely available. Here we briefly discuss the status of automotive PEMFCs misconceptions about the barriers that platinum usage creates and the remaining hurdles for the technology to become broadly accepted and implemented.

Renewable energy is considered the one of the most promising solutions to meet sustainable development goals in terms of climate change mitigation. Today we face the problem of further scaling up renewable energy infrastructure which requires the creation of reliable energy storages environmentally friendly carriers like hydrogen and competitive international markets. These issues provoke the involvement of resource-based countries in the energy transition which is questionable in terms of economic efficiency compared to conventional hydrocarbon resources. To shed a light on the possible efficiency of green hydrogen production in such countries this study is aimed at: (1) comparing key Russian trends of green hydrogen development with global trends (2) presenting strategic scenarios for the Russian energy sector development (3) presenting a case study of Russian hydrogen energy project «Dyakov Ust-Srednekanskaya HPP» in Magadan region. We argue that without significant changes in strategic planning and without focus on sustainable solutions support the further development of Russian power industry will be halted in a conservative scenario with the limited presence of innovative solutions in renewable energy industries. Our case study showed that despite the closeness to Japan hydrogen market economic efficiency is on the edge of zero with payback period around 17 years. The decrease in project capacity below 543.6 MW will immediately lead to a negative NPV. The key reason for that is the low average market price of hydrogen ($14/kg) which is only a bit higher than its production cost ($12.5/kg) while transportation requires about $0.96/kg more. Despite the discouraging results it should be taken into account that such strategic projects are at the edge of energy development. We see them as an opportunity to lead transnational energy trade of green hydrogen which could be competitive in the medium term especially with state support.

Two electrolysis technologies fed with renewable energy sources are promising for the production of CO₂-free hydrogen and enabling the transition to a hydrogen society: Alkaline Electrolyte (AE) and Polymer Electrolyte Membrane (PEM). However limited information exists on the potential environmental impacts of these promising sustainable innovations when operating on a large-scale. To fill this gap the performance of AE and PEM systems is compared using ex-ante Life Cycle Assessment (LCA) technology analysis and exploratory scenarios for which a refined methodology has been developed to study the effects of implementing large-scale sustainable hydrogen production systems. Ex-ante LCA allows modelling the environmental impacts of hydrogen production exploratory scenario analysis allows modelling possible upscaling effects at potential future states of hydrogen production and use in vehicles in the Netherlands in 2050. A bridging tool for mapping the technological field has been created enabling the combination of quantitative LCAs with qualitative scenarios. This tool also enables diversity for exploring multiple sets of visions. The main results from the paper show with an exception for the “ozone depletion” impact category (1) that large-scale AE and PEM systems have similar environmental impacts with variations lower than 7% in all impact categories (2) that the contribution of the electrolyser is limited to 10% of all impact categories results and (3) that the origin of the electricity is the largest contributor to the environmental impact contributing to more than 90% in all impact categories even when renewable energy sources are used. It is concluded that the methodology was applied successfully and provides a solid basis for an ex-ante assessment framework that can be applied to emerging technological systems.

The information in this report covers the period January 2019 – December 2019. The technology and market module of the FCHO presents a range of statistical data as an indicator of the health of the sector and the progress in market development over time. This includes statistical information on the size of the global fuel cell market including number and capacity of fuel cell systems shipped in a calendar year. For this first edition data to the end of 2019 is presented where possible alongside analysis of key sector developments. Fuel cell system shipments for each calendar year are presented both as numbers of units and total system megawatts. The data are further divided and subdivided by: • Application: Total system shipments are divided into Transport Stationary and Portable applications • Fuel cell type: Numbers are provided for each of the different fuel cell chemistry types • Region of integration: Region where the final manufacturer – usually the system integrator – integrates the fuel cell into the final product • Region of deployment: Region where the final product was shipped to for deployment The data is sourced directly from industry players as well as other relevant sources including press releases associations and other industry bodies.

Hybrid photovoltaic–regenerative hydrogen fuel cell (PV-RHFC) microgrid systems are considered to have a high future potential in the effort to increase the renewable energy share in the form of solar PV technology with hydrogen generation storage and reutilization. The current study provides a comprehensive review of the recent research progress of hybrid PV-RHFC microgrid systems to extract conclusions on their characteristics and future prospects. The different components that can be integrated (PV modules electrolyzer and fuel cell stacks energy storage units power electronics and controllers) are analyzed in terms of available technology options. The main modeling and optimization methods and control strategies are discussed. Additionally various application options are provided which differentiate in terms of scale purpose and further integration with other power generating and energy storage technologies. Finally critical analysis and discussion of hybrid PV-RHFC microgrid systems were conducted based on their current status. Overall the commercialization of hybrid PV-RHFC microgrid systems requires a significant drop in the RHFC subsystem capital cost. In addition it will be necessary to produce complete hybrid PV-RHFC microgrid systems with integrated energy management control capabilities to avoid operational issues and ensure flexibility and reliability of the energy flow in relation to supply storage and demand.

Achieving climate-neutrality requires considerable investment in energy storage systems (ESS) to integrate variable renewable energy sources into the grid. However investments into ESS are often unprofitable in particular for grid-scale battery storage and green hydrogen technologies prompting many actors to call for policy intervention. This study investigates investor-specific risk-return preferences for ESS investment and derives policy recommendations. Insights are drawn from 1605 experimental investment-related decisions obtained from 42 high-level institutional investors and utility representatives. Results reveal that both investor groups view revenue stacking as key to making ESS investment viable. While the expected return on investment is the most important project characteristic risk-return preferences for other features diverge between groups. Institutional investors appear more open to exploring new technological ventures (20% of utility respondents would not consider making investments into solar photovoltaic-hydrogen) whereas utilities seem to prefer greenfield projects (23% of surveyed institutional investors rejected such projects). Interestingly both groups show strong aversion towards energy market price risk. Institutional investors require a premium of 6.87 percentage points and utilities 5.54 percentage points for moving from a position of fully hedged against market price risk to a scenario where only 20% of revenue is fixed underlining the need for policy support.

In this present investigation a packed-filter bioreactor was employed to produce hydrogen utilizing an expired soft drink as a substrate. The effects of feeding substrate concentrations ranging from 19.51 10.19 5.34 3.48 to 2.51 g total sugar/L were examined and the position of the packed filter installed in the bioreactor at dimensionless heights (h/H) of 1/4 2/4 3/4 and 4/4 was studied. The results revealed that with a substrate concentration of 20 g total sugar/L and a hydraulic retention time (HRT) of 1 h a packed filter placed at the half-height position of the bioreactor (h/H 2/4) has the optimal hydrogen production rate hydrogen yield and average biomass concentration in the bioreactor resulting in 55.70 ± 2.42 L/L/d 0.90 ± 0.06 mol H₂/mol hexose and 17.86 ± 1.09 g VSS/L. When feeding substrate concentrations varied from 20 10 to 5 g total sugar/L with the packed-filter position at h/H 2/4 Clostridium sp. Clostridium tyrobutyricum and Bifidobacterium crudilactis were the predominant bacteria community. Finally it was discovered that the packed-filter bioreactor can produce stable hydrogen in high-strength organic effluent.

Energy-related GHG emissions mainly from fossil fuels combustion account for around 70% of total emissions. Those emissions are the target of the recent sustainability policies. Indeed renewables exploitation is considered widely the weapon to deal with this challenge thanks to their carbon neutrality. But the biggest drawback is represented by the mismatching between their production and users consumption. The storage would be a possible solution but its viability consists of economic sustainability and energy process efficiency as well. The cutting edge technologies of batteries have not still solved these issues at the same time. So a paradigm shift towards the identification of an energy carrier as storage option the so called Power-to-Gas could be the viable solution. From viability to feasibility a mandatory step is required: the opportunity to integrate the new solution in the proven infrastructures system. Thus the recent studies on Hydrogen (H2) enrichment in Natural Gas demonstrating a lower environmental impact and an increase in energy performance are the base to build the hydrogen transition in the urban environment. The aim of this paper is to evaluate the environmental benefits at building and district scale.

Hydrogen energy is one of the most suitable green substitutes for harmful fossil fuels and has been investigated widely. This review extensively compiles and compares various methodologies used in the production storage and usage of hydrogen. Sonochemistry is an emerging synthesis process and intensification technique adapted for the synthesis of novel materials. It manifests acoustic cavitation phenomena caused by ultrasound where higher rates of reactions occur locally. The review discusses the effectiveness of sonochemical routes in developing fuel cell catalysts fuel refining biofuel production chemical processes for hydrogen production and the physical chemical and electrochemical hydrogen storage techniques. The operational parameters and environmental conditions used during ultrasonication also influence the production rates which have been elucidated in detail. Hence this review's major focus addresses sonochemical methods that can contribute to the technical challenges involved in hydrogen usage for energy.

The search for fossil fuels substitutes forces the use of new propulsion technologies applied to means of transportation. Already widespread hybrid vehicles are beginning to share the market with hydrogen-powered propulsion systems. These systems are fuel cells or internal combustion engines powered by hydrogen fuel. In this context road tests of a hydrogen fuel cell drive were conducted under typical traffic conditions according to the requirements of the RDE test. As a result of the carried-out work energy flow conditions were presented for three driving phases (urban rural and motorway). The different contributions to the vehicle propulsion of the hydrogen system and the electric system in each phase of the driving route are indicated. The characteristic interaction of power train components during varying driving conditions was presented. A wide variation in the contribution of the fuel cell and the battery to the vehicle’s propulsion was identified. In urban conditions the share of the fuel cell in the vehicle’s propulsion is more than three times that contributed by the battery suburban—7 times highway—28 times. In the entire test the ratio of FC/BATT use was more than seven while the energy consumption was more than 22 kWh/100 km. The amounts of battery energy used and recovered were found to be very close to each other under RDE test conditions.

The carbide characteristics of 2.25Cr1Mo0.25V steel have an extremely important influence on the mechanical properties of welding joints. In addition hydrogen resistance behavior is crucial for steel applied in hydrogenation reactors. The carbide morphology was observed by scanning electron microscopy (SEM) and the carbide microstructure was characterized by transmission electron microscopy (TEM). Tensile and impact tests were carried out and the influence of carbides on properties was studied. A hydrogen diffusion test was carried out and the hydrogen brittleness resistance of welding metal and base metal was studied by tensile testing of hydrogenated samples to evaluate the influence of hydrogen on the mechanical properties. The research results show that the strength of the welding metal was slightly higher and the Charpy impact value was significantly lower compared to the base metal. The hydrogen embrittlement resistance of the welding metal was stronger than that of the base metal. The presence of more carbides and inclusions was the main cause of the decreased impact property and hydrogen brittleness resistance of the welding metal. These conclusions have certain reference value for designing and manufacturing hydrogenation reactors. View Full-Text

Decarbonisation should be very much on the radar of new LNG projects currently taking FID commissioning around 2024-25 and planning to operate up to 2050. The LNG community needs to replace an `advocacy’ message – based on the generality of emissions from combustion of natural gas being lower than from other fossil fuels – with certified data on carbon and methane emissions from specific elements of the value chain for individual projects. As carbon reduction targets tighten over the coming decade LNG cargoes which do not have value chain emissions certified by accredited authorities or which fail to meet defined emission levels run the risk of progressively being deemed to have a lower commercial value and eventually being excluded from jurisdictions with the strictest standards. There will be no place in this process for confidentiality; nothing less than complete transparency of data and methodologies will be acceptable.<br/>In relation to affordability prospects for new projects look much better than they did three years ago. Cost estimates for most new projects suggest that they will be able to deliver profitably to most established and anticipated import markets at or below the wholesale prices prevailing in those markets over the past decade although affordability in south Asian countries may be challenging. But new projects need to factor in costs related to future decarbonisation requirements in both exporting and importing countries. To the extent that LNG suppliers can meet standards through relatively low-cost offsets – forest projects low-cost biogas and biomethane – this may not greatly impact their commercial viability. However any requirement to transform methane into hydrogen with CCS in either the exporting or importing country would substantially impact project economics and the affordability of LNG relative to other energy choices.

The high strength of twinning-induced plasticity (TWIP) steels makes them vulnerable to the hydrogen embrittlement (HE) phenomenon thereby limiting their potential applications. This study suggests inducing a graded grain structure (GGS) in a Fe-17Mn-0.8C TWIP steel through shot peening and subsequent heat treatment to solve the problem. The microstructures and fracture surfaces of GGS TWIP steel were compared with those of conventionally manufactured TWIP steel possessing a uniform grain structure (UGS). Compared with the conventional UGS TWIP steel GGS steel showed similar tensile properties with a yield strength of 310 MPa tensile strength of 1060 MPa and elongation-to-failure of 135%. It also exhibited moderately enhanced low-cycle fatigue (LCF) resistance in terms of fatigue life (8196 cycles to failure) compared with the UGS steel (7201 cycles). Furthermore GGS TWIP steel exhibited a marked improvement in HE resistance both in the monotonic (by a slow-strain-rate test) and cyclic deformation modes (by the LCF test) in a hydrogen environment. A relatively fine-grained (d = 15.6 μm) surficial area enhanced the HE resistance by inhibiting hydrogen penetration and decreasing twin density while the coarse-grained (d = 74.6 μm) interior promoted the LCF resistance by suppressing crack growth

New technological solutions are required to control the impact of the increasing presence of renewable energy sources connected to the electric grid that are characterized by unpredictable production (i.e. wind and solar energy). Energy storage is becoming essential to stabilize the grid when a mismatch between production and demand occurs. Among the available solutions Power to Hydrogen (P2H) is one of the most attractive options. However despite the potential many barriers currently hinder P2H market development. The literature reports general barriers and strategies to overcome them but a specific analysis is fundamental to identifying how these barriers concretely arise in national and regional frameworks since tailored solutions are needed to foster the development of P2H local market. The paper aims to identify and to analyze the existing barriers for P2H market uptake in Italy. The paper shows how several technical regulatory and economic issues are still unsolved resulting in a source of uncertainty for P2H investment. The paper also suggests possible approaches and solutions to address the Italian barriers and to support politics and decision-makers in the definition and implementation of the national hydrogen strategy.

To become climate-neutral by 2050 Europe needs to transform its energy system which accounts for 75% of the EU's greenhouse gas emissions.  The EU strategies for energy system integration and hydrogen adopted today will pave the way towards a more efficient and interconnected energy sector driven by the twin goals of a cleaner planet and a stronger economy.<br/><br/>The two strategies present a new clean energy investment agenda in line with the Commission's Next Generation EU recovery package and the European Green Deal. The planned investments have the potential to stimulate the economic recovery from the coronavirus crisis. They create European jobs and boost our leadership and competitiveness in strategic industries which are crucial to Europe's resilience.

This paper summarizes a series of the authors’ research in the field of assessing the operational degradation of oil and gas transit pipeline steels. Both mechanical and electrochemical properties of steels are deteriorated after operation as is their resistance to environmentally-assisted cracking. The characteristics of resistance to brittle fracture and stress corrosion cracking decrease most intensively which is associated with a development of in-bulk dissipated microdamages of the material. The most sensitive indicators of changes in the material’s state caused by degradation are impact toughness and fracture toughness by the J-integral method. The degradation degree of pipeline steels can also be evaluated nondestructively based on in-service changes in their polarization resistance and potential of the fracture surface. Attention is drawn to hydrogenation of a pipe wall from inside as a result of the electrochemical interaction of pipe metal with condensed moisture which facilitates operational degradation of steel due to the combined action of operating stresses and hydrogen. The development of microdamages along steel texture was evidenced metallographically as a trend to the selective etching of boundaries between adjacent bands of ferrite and pearlite and fractographically by revealing brittle fracture elements on the fracture surfaces namely delamination and cleavage indicating the sites of cohesion weakening between ferrite and pearlite bands. The state of the X52 steel in its initial state and after use for 30 years was assessed based on the numerical simulation method.

Observing the growing energy demand of modern societies many countries have recognized energy security as a looming problem and renewable energies as a solution to this issue. Renewable hydrogen production is an excellent method for the storage and transfer of energy generated by intermittent renewable sources such as wind and solar so that they can be used at a place and time of our choosing. In this study the suitability of 15 cities in Fars province Iran for renewable hydrogen production was investigated and compared by the use of multiple multi-criteria decision-making methods including ARAS SAW CODAS and TOPSIS. The obtained rankings were aggregated by rank averaging Borda method and Copeland method. Finally the partially ordered set ranking technique was used to reach a general consensus about the ranking. The criteria that affect hydrogen production were found to be solar energy potential wind energy potential population air temperature natural disasters altitude relative humidity land cost skilled labor infrastructure topographic condition and distance from main roads. These criteria were weighted using the best–worst method (BWM) based on the data collected by a questionnaire. Solar energy potential was estimated using the Angstrom model. Wind energy potential was estimated by using the Weibull distribution function for each month independently. The results of the multi-criteria decision-making methods showed Izadkhast to be the most suitable location for renewable hydrogen production in the studied area.

Hydrogen is receiving increasing attention as a versatile energy vector to help accelerate the transition to a decarbonised energy future. Gas turbines will continue to play a critical role in providing grid stability and resilience in future low-carbon power systems; however it is recognised that this role is contingent upon achieving increased thermal efficiencies and the ability to operate on carbon-neutral fuels such as hydrogen. An important consideration in the development of gas turbine combustors capable of operating with pure hydrogen or hydrogen-enriched natural gas are the significant changes in thermoacoustic instability characteristics associated with burning these fuels. This article provides a review of the effects of burning hydrogen on combustion dynamics with focus on swirl-stabilised lean-premixed combustors. Experimental and numerical evidence suggests hydrogen can have either a stabilising or destabilising impact on the dynamic state of a combustor through its influence particularly on flame structure and flame position. Other operational considerations such as the effect of elevated pressure and piloting on combustion dynamics as well as recent developments in micromix burner technology for 100% hydrogen combustion have also been discussed. The insights provided in this review will aid the development of instability mitigation strategies for high hydrogen combustion.

The rapid development of science technology and engineering in the 21st century has offered a remarkable rise in our living standards. However at the same time serious environmental issues have emerged such as acid rain and the greenhouse effect which are associated with the ever-increasing need for energy consumption 85% of which comes from fossil fuels combustion. From this combustion process except for energy the main greenhouse gases-carbon dioxide and steam-are produced. Moreover during industrial processes many hazardous gases are emitted. For this reason gas-detecting devices such as electrochemical gas sensors able to analyze the composition of a target atmosphere in real time are important for further improving our living quality. Such devices can help address environmental issues and inform us about the presence of dangerous gases. Furthermore as non-renewable energy sources run out there is a need for energy saving. By analyzing the composition of combustion emissions of automobiles or industries combustion processes can be optimized. This review deals with electrochemical gas sensors based on solid oxide electrolytes which are employed for the detection of hazardous gasses at high temperatures and aggressive environments. The fundamentals the principle of operation and the configuration of potentiometric amperometric combined (amperometric-potentiometric) and mixed-potential gas sensors are presented. Moreover the results of previous studies on carbon oxides (COx) nitrogen oxides (NOx) hydrogen (H2 ) oxygen (O2 ) ammonia (NH3 ) and humidity (steam) electrochemical sensors are reported and discussed. Emphasis is given to sensors based on oxygen ion and proton-conducting electrolytes.

Extreme halophiles offer the advantage to save on the costs of sterilization and water for biohydrogen production from lignocellulosic waste after the pretreatment process with their ability to withstand extreme salt concentrations. This study identifies the dominant hydrogen-producing genera and species among the acclimatized extremely halotolerant microbial communities taken from two salt-damaged soil locations in Khon Kaen and one location from the salt evaporation pond in Samut Sakhon Thailand. The microbial communities’ V3–V4 regions of 16srRNA were analyzed using high-throughput amplicon sequencing. A total of 345 operational taxonomic units were obtained and the high-throughput sequencing confirmed that Firmicutes was the dominant phyla of the three communities. Halanaerobium fermentans and Halanaerobacter lacunarum were the dominant hydrogen-producing species of the communities. Spatial proximity was not found to be a determining factor for similarities between these extremely halophilic microbial communities. Through the study of the microbial communities strategies can be developed to increase biohydrogen molar yield.

Low-cost high-performance coatings for hydrogen production via electrolytic water-splitting are of great importance for de-carbonising energy. In this study the Raney2.0 coating was analysed using various electrochemical techniques to assess its absolute performance and it was confirmed to have an extremely low overpotential for hydrogen evolution of just 28 mV at 10 mA/cm². It was also confirmed to be an acceptable catalyst for oxygen evolution making it the highest performing simple bifunctional electrocatalyst known. The coating exhibits an extremely high capacitance of up to 1.7 F/cm² as well as being able to store 0.61 J/cm² in the form of temporary hydride deposits. A new technique is presented that performs a best-fit of a transient simulation of an equivalent circuit containing a constant phase element to cyclic voltammetry measurements. From this the roughness factor of the coating was calculated to be approximately 40000 which is the highest figure ever reported for this type of material. The coating is therefore an extremely useful improved bifunctional coating for the continued roll-out of alkaline electrolysis for large-scale renewable energy capture via hydrogen production.

As the energy crisis becomes worse hydrogen as a clean energy source is more and more widely used in industrial production and people’s daily life. However there are hidden dangers in hydrogen storage and transportation because of its flammable and explosive features. Gas detection is the key to solving this problem. High quality sensors with more practical and commercial value must be able to accurately detect target gases in the environment. Emerging porous metal-organic framework (MOF) materials can effectively improve the selectivity of sensors as a result of high surface area and coordinated pore structure. The application of MOFs for surface modification to improve the selectivity and sensitivity of metal oxides sensors to hydrogen has been widely investigated. However the influence of MOF modified film thickness on the selectivity of hydrogen sensors is seldom studied. Moreover the mechanism of the selectivity improvement of the sensors with MOF modified film is still unclear. In this paper we prepared nano-sized ZnO particles by a homogeneous precipitation method. ZnO nanoparticle (NP) gas sensors were prepared by screen printing technology. Then a dense ZIF-8 film was grown on the surface of the gas sensor by hydrothermal synthesis. The morphology the composition of the elements and the characters of the product were analyzed by X-ray diffraction analysis (XRD) transmission electron microscope (TEM) scanning electron microscope (SEM) energy dispersive spectrometer (EDS) Brunauer-Emmett-Teller (BET) and differential scanning calorimetry (DSC). It is found that the ZIF-8 film grown for 4 h cannot form a dense core-shell structure. The thickness of ZIF-8 reaches 130 nm at 20 h. Through the detection and analysis of hydrogen (1000 ppm) ethanol (100 ppm) and acetone (50 ppm) from 150 °C to 290 °C it is found that the response of the ZnO@ZIF-8 sensors to hydrogen has been significantly improved while the response to ethanol and acetone was decreased. By comparing the change of the response coefficient when the thickness of ZIF-8 is 130 nm the gas sensor has a significantly improved selectivity to hydrogen at 230 °C. The continuous increase of the thickness tends to inhibit selectivity. The mechanism of selectivity improvement of the sensors with different thickness of the ZIF-8 films is discussed.

Proposed sustainable transition pathways for moving away from natural gas in domestic heating focus on two main energy vectors: electricity and hydrogen. Electrification would be implemented by using vapourcompression heat pumps which are currently experiencing market growth in many countries. On the other hand hydrogen could substitute natural gas in boilers or be used in thermally–driven absorption heat pumps. In this paper a consistent thermodynamic and economic methodology is developed to assess the competitiveness of these options. The three technologies along with the option of district heating are for the first time compared for different weather/ambient conditions and fuel-price scenarios first from a homeowner’s and then from a wholeenergy system perspective. For the former two-dimensional decision maps are generated to identify the most cost-effective technologies for different combinations of fuel prices. It is shown that in the UK hydrogen technologies are economically favourable if hydrogen is supplied to domestic end-users at a price below half of the electricity price. Otherwise electrification and the use of conventional electric heat pumps will be preferred. From a whole-energy system perspective the total system cost per household (which accounts for upstream generation and storage as well as technology investment installation and maintenance) associated with electric heat pumps varies between 790 and 880 £/year for different scenarios making it the least-cost decarbonisation pathway. If hydrogen is produced by electrolysis the total system cost associated with hydrogen technologies is notably higher varying between 1410 and 1880 £/year. However this total system cost drops to 1150 £/year with hydrogen produced cost-effectively by methane reforming and carbon capture and storage thus reducing the gap between electricity- and hydrogen-driven technologies.

To maximise power density practical gas turbine combustion systems have several injectors which can lead to complex interactions between flames. However our knowledge about the effect of flame-flame interactions on the flame response the essential element to predict the stability of a combustor is still limited. The present study investigates the effect of hydrogen enrichment flame-flame interaction confinement and asymmetries on the linear and non-linear acoustic response of three premixed flames in a simple can combustor. A parametric study of the linear response characterised by the flame transfer function (FTF) is performed for swirling and non-swirling flames. Flame-flame interactions were achieved by changing the injector spacing and the level of hydrogen enrichment by power from 10 to 50%. It was found that the latter had the most significant effect on the flame response. Asymmetry effects were investigated by changing one of the flames by using a different bluff-body to alter both the flame shape and flow field. The global flame response showed that the asymmetric cases can be reconstructed using a superposition of the two symmetric cases where all three bluff-bodies and flames are the same. Overall the linear response characterised by the flame transfer function (FTF) showed that the effect of increasing the level of hydrogen enrichment is more pronounced than the effect of the injector spacing. Increasing hydrogen enrichment results in more compact flames which minimises flame-flame interactions. More compact flames increase the cut-off frequency which can lead to self-excited modes at higher frequencies. Finally the non-linear response was characterised by measuring the flame describing function (FDF) at a frequency close to a self-excited mode of the combustor for different injector spacings and levels of hydrogen enrichment. It is shown that increasing the hydrogen enrichment leads to higher saturation amplitude whereas the effect of injector spacing has a comparably smaller effect.

These two joint reports required under the Environment (Wales) Act 2016 provide ministers with advice on Wales’ climate targets between now and 2050 and assess progress on reducing emissions to date. Our advice to the Welsh Government is set out in two parts:

Advice Report: The path to a Net Zero Wales provides recommendations on the actions that are needed in Wales including the legislation of a Net Zero target and package of policies to deliver it.

Progress Report: Reducing emissions in Wales looks back at the progress made in Wales since the 2016 Environment (Wales) Act was passed and assesses whether Wales is on track to meet its currently legislated emissions reductions targets.

This work is based on an extensive programme of analysis consultation and consideration by the Committee and its staff building on the evidence published last year for our Net Zero report. It is compatible with our advice on the UK’s Sixth Carbon Budget. In support of the advice in this report we have also published:

• All the charts and data behind the report as well as a separate dataset for the scenarios which sets out more details and data on the pathways than can be included in this report.
• A public Call for Evidence several new research projects three expert advisory groups and deep dives into the roles of local authorities and businesses.

Greenhouse gas emissions need to be drastically reduced to mitigate the environmental impacts caused by climate change and to lead to a transformation of the European energy system. A model landscape consisting of four final energy consumption sector models with high spatial (NUTS-3) and temporal (hourly) resolution and the multi-energy system model ISAaR is extended and applied to investigate the transformation pathway of the European energy sector in the deep emission mitigation scenario solidEU. The solidEU scenario describes not only the techno-economic but also the socio-political contexts and it includes the EU27 + UK Norway and Switzerland. The scenario analysis shows that volatile renewable energy sources (vRES) dominate the energy system in 2050. In addition the share of flexible sector coupling technologies increases to balance electricity generation from vRES. Seasonal differences are balanced by hydrogen storage with a seasonal storage profile. The deployment rates of vRES in solidEU show that a fast profound energy transition is necessary to achieve European climate protection goals.

Prestressing steel wires are highly susceptible to hydrogen embrittlement (HE). Residual stress-strain state produced after wire drawing plays an essential role since hydrogen damage at certain places of the material is directly affected by stress and strain fields. Changes in wire drawing conditions modify the stress and strain fields and consequently the HE susceptibility and life in service of these structural components in the presence of a hydrogenating environment. This paper analyzes the distributions of residual stress and plastic strain obtained after diverse drawing conditions (inlet die angle die bearing length varying die angle and straining path) and their influence on HE susceptibility of the wires. The conditions for industrial cold drawing can thus be optimized thereby producing commercial prestressing steel wires with improved performance against HE phenomena.

The Australian transport sector is under increasing pressure to reduce carbon emissions whilst also managing a fuel supply chain that relies heavily on foreign import partners.



Transport in Australia equates to a significant proportion (approximately 18%) of the country’s total greenhouse gas emissions. Due to ongoing population growth these emissions have been steadily rising with the increase of cars on our roads and freight trucks in transit. Coupled with this the transport fuel supply chain is highly reliant on overseas partners – Australia currently imports 90% of its liquid fuel. These two challenges present an interesting dichotomy for the industry incentivising research and development into new technologies that can address one or both of these issues.



Hydrogen is one technology that has the potential to provide a reduction in greenhouse gas emissions as well as a more reliable domestic fuel supply. Hydrogen fuel cell electric vehicles (FCEVs) are an emerging zero-emission alternative for the transport sector which offer a variety of benefits.



Available from the Energy Ministers Website link here

Fischer-Tropsch synthesis (FTS) is an increasingly important approach for producing liquid fuels and chemicals via syngas—that is synthesis gas a mixture of carbon monoxide and hydrogen—generated from coal natural gas or biomass. In FTS dispersed transition metal nanoparticles are used to catalyze the reactions underlying the formation of carbon-carbon bonds. Catalytic activity and selectivity are strongly correlated with the electronic and geometric structure of the nanoparticles which depend on the particle size morphology and crystallographic phase of the nanoparticles. In this article we review recent works dealing with the aspects of bulk and surface sensitivity of the FTS reaction. Understanding the different catalytic behavior in more detail as a function of these parameters may guide the design of more active selective and stable FTS catalysts.

Proton exchange membrane (PEM) electrolysers (PEMEL) are key for converting and storing excess renewable energy. PEMEL water electrolysis offers benefits over alkaline water electrolysers including a large dynamic range high responsiveness and high current densities and pressures. High operating pressures are important because it contributes to reduce the costs and energy-use related to downstream mechanical compression. In this work the performance of a high-pressure PEMEL system has been characterized up to 180 bar. The electrolyser stack has been characterized with respect to electrochemical performance net H2 production rate and water crossover and the operability and performance of the thermal- and gas management systems of the test bench has been assessed. The tests show that the voltage increase upon pressurization from 5 to 30 bar is 30 % smaller than expected but further pressurization reduces performance. The study confirms that highpressure PEMEL has higher energy consumption than state-of-the-art electrolyser systems with mechanical compressors. However there can be a business case for high-pressure PEMEL if the trade-off between stack efficiency and system efficiency is balanced.

The deployment of low-emission alternative fuels is crucial to decarbonise the transport sector. A number of alternatives like hydrogen or dimethyl ether/methanol synthesised using CO2 as feedstock for fuel production (hereafter refer to “CO2-based fuels”) have been proposed to combat climate change. However the decarbonisation potential of CO2-based fuels is under debate because CO2 is re-emitted to the atmosphere when the fuel is combusted; and the majority of hydrogen still relies on fossil resources which makes its prospects of being a low-carbon fuel dependent on its manufacturing process. First this paper investigates the relative economic and environmental performance of hydrogen (produced from conventional steam methane reforming and produced via electrolysis using renewable energy) and CO2- based fuels (dimethyl ether and methanol) considering the full carbon cycle. The results reveal that hydrogen produced from steam methane reforming is the most economical option and that hydrogen produced via electrolysis using renewables has the best environmental profile. Whereas the idea of CO2-based fuels has recently gained much interest it has for the foreseeable future rather limited practical relevance since there is no favourable combination of cost and environmental performance. This will only change in the long run and requires that CO2 is of non-fossil origin i.e. from biomass combustion or captured from air. Second this paper address unresolved methodological issues in the assessment of CO2-based fuels such as the possible allocation of emissions to the different sectors involved. The outcomes indicate that implementing different allocation approaches substantially influences the carbon footprint of CO2-based fuels. To avoid allocation issues expanding the boundaries including the entire system and is therefore recommended.

Hydrogen has seen unprecedented development in the year 2020. From innovative niche technology it is fast becoming a systemic element in the European Union’s (EU) efforts to transition to a climate-neutral society in 2050. It will become a crucial energy vector and the other leg of the energy transition – alongside renewable electricity – by replacing coal oil and gas across different segments of the economy. The rapid development of hydrogen is important for meeting the EU’s climate objectives and preserving and enhancing the EU’s industrial and economic competitiveness securing jobs and value creation in this high-tech sector.

Europe is currently leading in hydrogen technology and European companies and knowledge institutions can be instrumental in advancing technological developments and industrial scale-up. It is imperative that Europe maintains this leadership position and seizes the current momentum for hydrogen technologies. The EU is well placed to become the birthplace of a global hydrogen economy denominated in Euro currency.

It is time that hydrogen moves from an afterthought to a central pillar of the energy system. The “Fit for 55 Package” presents a unique opportunity to begin putting into place a concrete and fit for purpose framework for the development of a clean hydrogen economy. In this paper you will find Hydrogen Europe’s recommendations on how hydrogen can:

• Unleash the potential of renewables.
• Bring “efficiency” to the energy “system” of the future.
• Enable a carbon-neutral transport system.

The Oxford Institute for Energy Studies held a Workshop on “The Future of Gas Networks” to examine decarbonisation plans and the impact of the potential growth in the use of renewable and decarbonised gases in Europe. Participants included representatives from nine European gas network companies (both transmission and distribution) technical experts in decarbonisation regulators government officials and academics. This document summarises the seven key issues for debate arising from the Workshop discussions:

• The major gas networks recognise the need to prepare for and facilitate decarbonisation.
• The route to decarbonisation can take many forms though hydrogen is likely to feature in most networks. In larger countries solutions are likely to be regional rather than national.
• There are a number of pilot projects and targets/aspirations for 2050 – there is less clarity on how the targets will be achieved or on who will lead.
• Regulation is a key issue. In most countries existing regulatory objectives may need changing in order to align with government decarbonisation aspirations and the achievement of targets.
• There is a lack of consensus on whether and how market models might need to adapt.
• Detailed stakeholder analysis – and in particular customer attitudes – will be required.
• There are a range of important technical issues including standardisation data quality and transparency verification and certification to be considered.

Link to document on Oxford Institute for Energy Studies website

Due to the low density of hydrogen gas under ambient temperature and atmospheric pressure conditions the high-pressure gaseous hydrogen storage method is widely employed. With high-pressure characteristics of hydrogen storage rigorous safety precautions are required such as filling of compressed gas in a hydrogen tank to achieve reliable operational solutions. Especially for the large-sized tanks (above 150 L) safety operation of hydrogen storage should be considered. In the present study the compressed hydrogen gas behavior in a large hydrogen tank of 175 L is investigated for its filling. To validate the numerical approach used in this study numerical models for the adaptation of the gas and turbulence models are examined. Numerical parametric studies on hydrogen filling for the large hydrogen tank of 175 L are conducted to estimate the hydrogen gas behavior in the hydrogen tank under various conditions of state of charge of pressure and ambient temperature. From the parametric studies the relationship between the initial SOC pressure condition and the maximum temperature rise of hydrogen gas was shown. That is the maximum temperature rise increases as the ambient temperature decreases and the rise increases as the SOC decreases.

The computational thermodynamic analysis of a samarium oxide-based two-step solar thermochemical water splitting cycle is reported. The analysis is performed using HSC chemistry software and databases. The first (solar-based) step drives the thermal reduction of Sm2O3 into Sm and O2. The second (non-solar) step corresponds to the production of H2 via a water splitting reaction and the oxidation of Sm to Sm2O3. The equilibrium thermodynamic compositions related to the thermal reduction and water splitting steps are determined. The effect of oxygen partial pressure in the inert flushing gas on the thermal reduction temperature (TH) is examined. An analysis based on the second law of thermodynamics is performed to determine the cycle efficiency (ηcycle) and solar-to-fuel energy conversion efficiency (ηsolar´to´fuel) attainable with and without heat recuperation. The results indicate that ηcycle and ηsolar´to´fuel both increase with decreasing TH due to the reduction in oxygen partial pressure in the inert flushing gas. Furthermore the recuperation of heat for the operation of the cycle significantly improves the solar reactor efficiency. For instance in the case where TH = 2280 K ηcycle = 24.4% and ηsolar´to´fuel = 29.5% (without heat recuperation) while ηcycle = 31.3% and ηsolar´to´fuel = 37.8% (with 40% heat recuperation).

To limit the global temperature change to no more than 2 ◦C by reducing global emissions the European Union (EU) set up a goal of a 20% improvement on energy efficiency a 20% cut of greenhouse gas emissions and a 20% share of energy from renewable sources by 2020 (10% share of renewable energy (RE) specifically in the transport sector). By 2030 the goal is a 27% improvement in energy efficiency a 40% cut of greenhouse gas emissions and a 27% share of RE. However the integration of RE in energy system faces multiple challenges. The geographical distribution of energy supply changes significantly the availability of the primary energy source (wind solar water) and is the determining factor rather than where the consumers are. This leads to an increasing demand to match supply and demand for power. Especially intermittent RE like wind and solar power face the issue of energy production unrelated to demand (issue of excess energy production beyond demand and/or grid capacity) and forecast errors leading to an increasing demand for grid services like balancing power. Megawatt electrolyzer units (beyond 3 MW) can provide a technical solution to convert large amounts of excess electricity into hydrogen for industrial applications substitute for natural gas or the decarbonization of the mobility sector. The demonstration of successful MW electrolyzer operation providing grid services under dynamic conditions as request by the grid can broaden the opportunities of new business models that demonstrate the profitability of an electrolyzer in these market conditions. The aim of this work is the demonstration of a technical solution utilizing Pressurized Alkaline Electrolyzer (PAE) technology for providing grid balancing services and harvesting Renewable Energy Sources (RES) under realistic circumstances. In order to identify any differences between local market and grid requirements the work focused on a demonstration site located in Austria deemed as a viable business case for the operation of a largescale electrolyzer. The site is adapted to specific local conditions commonly found throughout Europe. To achieve this this study uses a market-based solution that aims at providing value-adding services and cash inflows stemming from the grid balancing services it provides. Moreover the work assesses the viability of various business cases by analyzing (qualitatively and quantitatively) additional business models (in terms of business opportunities/energy source potential grid service provision and hydrogen demand) and analyzing the value and size of the markets developing recommendations for relevant stakeholder to decrease market barriers.

Owing to their extremely high energy density single-bonded polymeric nitrogen and atomic metallic hydrogen are generally regarded as the ultimate energetic materials. Although their syntheses normally require ultrahigh pressures of several hundred gigapascals (GPa) which prohibit direct materials application research on their stability metastability and fundamental properties are valuable for seeking extreme energetic materials through alternative synthetic routes. Various crystalline and amorphous polymeric nitrogens have been discovered between 100 and 200 GPa. Metastability at ambient conditions has been demonstrated for some of these phases. Cubic-gauche and black-phosphorus polymorphs of single-bonded nitrogen are two particularly interesting phases. Their large hystereses warrant further application-inspired basic research of nitrogen. In contrast although metallic hydrogen contains the highest-estimated energy density its picosecond lifetime and picogram quantity make its practical material application impossible at present. “Metallic hydrogen” remains a curiosity-driven basic research pursuit focusing on the pressure-induced evolution of the molecular hydrogen crystal and its electronic band structure from a low-density insulator with a very wide electronic band gap to a semiconductor with a narrow gap to a dense molecular metal and atomic metal and eventually to a previously unknown exotic state of matter. This great experimental challenge is driving relentless advancement in ultrahigh-pressure science and technology.