Publications

Hydrogen fuel cell vehicle (HFCV) technology poses great promise as an alternative to significantly reduce the environmental impact of the transport sector’s emissions. However hydrogen fuel cell technology is relatively new therefore confirmation of the reliability and safety analysis is still required particularly for fire scenarios within confined spaces such as tunnels. This study applied the computational fluid dynamics (CFD) simulations in conjunction with probabilistic calculation methods to determine the associated thermal risk of a hydrogen jet fire in a tunnel and its dependency on scenarios with different tunnel slopes longitudinal and transverse ventilation velocities and fire positions. A large-scale model of 102 m in which the effects of outlined parameter variations on the severity of the fire incident were analysed. It is found that both tunnel ventilation techniques and slope were critical for the effective ejection of accumulated heat. With ventilation playing a primary role in the ejection of heat and gas and slope ensuring the stability of the ejected heat probabilities of thermal burns were found to be reduced by up to approximately 35% with a strong suggestion of critical combinations to further reduce the dangers of hydrogen tunnel fires.

Water electrolysis for hydrogen production has received increasing attention especially for accumulating renewable energy. Here we comprehensively reviewed all water electrolysis research areas through computational analysis using a citation network to objectively detect emerging technologies and provide interdisciplinary data for forecasting trends. The results show that all research areas increase their publication counts per year and the following two areas are particularly increasing in terms of number of publications: “microbial electrolysis” and “catalysts in an alkaline water electrolyzer (AWE) and in a polymer electrolyte membrane water electrolyzer (PEME).”. Other research areas such as AWE and PEME systems solid oxide electrolysis and the whole renewable energy system have recently received several review papers although papers that focus on specific technologies and are cited frequently have not been published within the citation network. This indicates that these areas receive attention but there are no novel technologies that are the center of the citation network. Emerging technologies detected within these research areas are presented in this review. Furthermore a comparison with fuel cell research is conducted because water electrolysis is the reverse reaction to fuel cells and similar technologies are employed in both areas. Technologies that are not transferred between fuel cells and water electrolysis are introduced and future water electrolysis trends are discussed.

The increasing penetration of variable renewable energies poses new challenges for grid management. The  economic feasibility of grid-balancing plants may be limited by low annual operating hours if they work either only for power generation or only for power storage. This issue might be addressed by a dual-function power plant with power-to-x capability which can produce electricity or store excess renewable electricity into chemicals at different periods. Such a plant can be uniquely enabled by a solid-oxide cell stack which can switch between fuel cell and electrolysis with the same stack. This paper investigates the optimal conceptual design of this type of plant represented by power-to-x-to-power process chains with x being hydrogen syngas methane methanol and ammonia concerning the efficiency (on a lower heating value) and power densities. The results show that an increase in current density leads to an increased oxygen flow rate and a decreased reactant utilization at the stack level for its thermal management and an increased power density and a decreased efficiency at the system level. The power-generation efficiency is ranked as methane (65.9%) methanol (60.2%) ammonia (58.2%) hydrogen (58.3%) syngas (53.3%) at 0.4 A/cm2 due to the benefit of heat-to-chemical-energy conversion by chemical reformulating and the deterioration of electrochemical performance by the dilution of hydrogen. The power-storage efficiency is ranked as syngas (80%) hydrogen (74%) methane (72%) methanol (68%) ammonia (66%) at 0.7 A/cm2 mainly due to the benefit of co-electrolysis and the chemical energy loss occurring in the chemical synthesis reactions. The lost chemical energy improves plant-wise heat integration and compensates for its adverse effect on power-storage efficiency. Combining these efficiency numbers of the two modes results in a rank of round-trip efficiency: methane (47.5%)>syngas (43.3%) ≈ hydrogen (42.6%)>methanol (40.7%)>ammonia (38.6%). The pool of plant designs obtained lays the basis for the optimal deployment of this balancing technology for specific applications.

Hydrogen is an environmentally friendly source of renewable energy. Energy generation from hydrogen has not yet been widely commercialized due to issues related to risk management in its storage and transportation. In this paper the authors propose a hybrid multiple-criteria decision-making (MCDM)-based method to manage the risks involved in the storage and transportation of hydrogen (RSTH). First we identified the key points of the RSTH by examining the relevant literature and soliciting the opinions of experts and used this to build a prototype of its decision structure. Second we developed a hybrid MCDM approach called the D-ANP that combined the decision-making trial and evaluation laboratory (DEMENTEL) with the analytic network process (ANP) to obtain the weight of each point of risk. Third we used fuzzy evaluation to assess the level of the RSTH for Beijing China where energy generation using hydrogen is rapidly advancing. The results showed that the skills of the personnel constituted the most important risk-related factor and environmental volatility and the effectiveness of feedback were root factors. These three factors had an important impact on other factors influencing the risk of energy generation from hydrogen. Training and technical assistance can be used to mitigate the risks arising due to differences in the skills of personnel. An appropriate logistics network and segmented transportation for energy derived from hydrogen should be implemented to reduce environmental volatility and integrated supply chain management can help make the relevant feedback more effective.

Today we are joined by our good friends from Enapter. The company is a leader in the clean hydrogen sector focused on AEM electrolyzer technology and innovative software solutions that make it possible to rapidly deploy and scale hydrogen production assets. For those who follow the hydrogen sector regularly it’s been hard not to hear Enapter-related news in 2021 and its impressive trajectory as they have gone public announced the plans for a brand new production facility in Germany (on which they have now begun construction) and most recently the announcement that Enapter was selected as the winner of the prestigious Earthshot prize. To do that we are absolutely delighted to have with us all the way from his home base in Thailand Thomas Chrometzka Chief Strategy Officer at Enapter and one of the people that we enjoy having on the show so much that we have brought him back again to fill us in on what he and Enapter are up to and what they have planned for the future of hydrogen.

The podcast can be found on their website

The North Sea region located in the Northwest of Europe is expected to be a frontrunner in the European energy transition. This paper aims to analyse different optimal system configurations in order to meet net-zero emission targets in 2050. Overall the paper presents two main contributions: first we develop and introduce the IESA-NS model. The IESA-NS model is an optimization integrated energy system model written as a linear problem. The IESA-NS model optimizes the long-term investment planning and short-term operation of seven North Sea region countries (Belgium Denmark Germany the Netherlands Norway Sweden and the United Kingdom). The model can optimize multiple years simultaneously accounts for all the national GHG emissions and includes a thorough representation of all the sectors of the energy system. Second we run several decarbonisation scenarios with net-zero emission targets in 2050. Relevant parameters varied to produce the scenarios include biomass availability VRE potentials low social acceptance of onshore VRE ban of CCUS or mitigation targets in international transport and industry feedstock. Results show a large use of hydrogen when international transport emissions are considered in the targets (5.6 EJ to 7.3 EJ). Electrolysis is the preferred pathway for hydrogen production (up to 6.4 EJ) far ahead of natural gas reforming (up to 2.2 EJ). Allowing offshore interconnectors (e.g. meshed offshore grid between the Netherlands Germany and the United Kingdom) permits to integrate larger amounts of offshore wind (122 GW to 191 GW of additional capacity compared to reference scenarios) while substantially increasing the cross-border interconnection capacities (up to 120 GW). All the biomass available is used in the scenarios across multiple end uses including biofuel production (up to 3.5 EJ) high temperature heat (up to 2.5 EJ) feedstock for industry (up to 2 EJ) residential heat (up to 600 PJ) and power generation (up to 900 PJ). In general most of the results justify the development of multinational energy system models in which the spatial coverage lays between national and continental models.

The present work aims to assess the influence of the composition of blends of hydrogen (H2 ) and Natural Gas (NG) on Dual Fuel (DF) combustion characteristics including gaseous emissions. The 3D-CFD study is carried out by means of a customized version of the KIVA-3V code. An automotive 2.8 L 4-cylinder turbocharged diesel engine was previously modified in order to operate in DF NG–diesel mode and tested at the dynamometer bench. After validation against experimental results the numerical model is applied to perform a set of combustion simulations at 3000 rpm–BMEP = 8 bar in DF H2/NG-diesel mode. Different H2–NG blends are considered: as the H2 mole fraction varies from 0 vol% to 50 vol% the fuel energy within the premixed charge is kept constant. The influence of the diesel Start Of Injection (SOI) is also investigated. Simulation results demonstrate that H2 enrichment accelerates the combustion process and promotes its completion strongly decreasing UHC and CO emissions. Evidently CO2 specific emissions are also reduced (up to about 20% at 50 vol% of H2 ). The main drawbacks of the faster combustion include an increase of in-cylinder peak pressure and pressure rate rise and of NOx emissions. However the study demonstrates that the optimization of diesel SOI can eliminate all aforementioned shortcomings.

This  paper  reports  on  the  results  of  interviews  conducted  with  21  representatives  from   emergency services organisations within Australia and New Zealand. With a relative emergent industry such as future fuels a chicken and egg situation does emerge with regards to how much training needs to be in place in advance of large-scale industry development or not. These respondents were employed in a variety of roles being directly involved in research and training of emerging technologies frontline operational  managers  and  other  senior  roles  across  the   emergency  services  sector.  Participants' responses to a series of questions were able to provide insights into the state of knowledge and training requirements within their organisations in relation to hydrogen and other future fuels. The findings suggest that formal and informal processes currently exist to support the knowledge development and transferal around the adoption of hydrogen and other future fuels. From the interviews it became clear that  there  are  a  number  of  processes  that  have  emerged  from  the  experiences  gained  through  the implementation   of  rooftop  solar  PV  and  battery  storage  that  provide  some  background  context  for advancing future fuels information across the sector. Because safety is a critical component for securing a social licence to operate engagement and knowledge sharing with any representatives from across this sector will only help to build confidence in the industry. Similarly because interviewees were very keen to access information they expressed a clear willingness to learn more through more formalised relationships rather than an ad hoc information seeking that has been employed to date. The presentation will  identify  key  recommendations  and  also  highlight  the   importance  of  QR  Codes in the emergency responder landscape. Implications for industry and policy makers are discussed.

In some areas the problem of wind and solar power curtailment is prominent. Hydrogen energy has the advantage of high storage density and a long storage time. Multi-energy hybrid systems including renewable energies batteries and hydrogen are designed to solve this problem. In order to reduce the power loss of the converter an AC-DC hybrid bus is proposed. A multi-energy experiment platform is established including a wind turbine photovoltaic panels a battery an electrolyzer a hydrogen storage tank a fuel cell and a load. The working characteristics of each subsystem are tested and analyzed. The multi-energy operation strategy is based on state monitoring and designed to enhance hydrogen utilization energy efficiency and reliability of the system. The hydrogen production is guaranteed preferentially and the load is reliably supplied. The system states are monitored such as the state of charge (SOC) and the hydrogen storage level. The rated and ramp powers of the battery and fuel cell and the pressure limit of the hydrogen storage tank are set as safety constraints. Eight different operation scenarios comprehensively evaluate the system’s performance and via physical experiments the proposed operation strategy of the multi-energy system is verified as effective and stable.

This study analyzes the factors leading to the deployment of Power-to-Hydrogen (PtH₂) within the optimal design of district-scale Multi-Energy Systems (MES). To this end we utilize an optimization framework based on a mixed integer linear program that selects sizes and operates technologies in the MES to satisfy electric and thermal demands while minimizing annual costs and CO₂ emissions. We conduct a comprehensive uncertainty analysis that encompasses the entire set of technology (e.g. cost efficiency lifetime) and context (e.g. economic policy grid carbon footprint) input parameters as well as various climate-referenced districts (e.g. environmental data and energy demands) at a European-scope.

Minimum-emissions MES with large amounts of renewable energy generation and high ratios of seasonal thermal-to-electrical demand optimally achieve zero operational CO₂ emissions by utilizing PtH₂ seasonally to offset the long-term mismatch between renewable generation and energy demand. PtH₂ is only used to abate the last 5–10% emissions and it is installed along with a large battery capacity to maximize renewable self-consumption and completely electrify thermal demand with heat pumps and fuel cells. However this incurs additional cost. Additionally we show that ‘traditional’ MES comprised of renewables and short-term energy storage are able to decrease emissions by 90% with manageable cost increases.

The impact of uncertainty on the optimal system design reveals that the most influential parameter for PtH2 implementation is (1) heat pump efficiency as it is the main competitor in providing renewable-powered heat in winter. Further battery (2) capital cost and (3) lifetime prove to be significant as the competing electrical energy storage technology. In the face of policy uncertainties a CO₂ tax shows large potential to reduce emissions in district MES without cost implications. The results illustrate the importance of capturing the dynamics and uncertainties of short- and long-term energy storage technologies for assessing cost and CO₂ emissions in optimal MES designs over districts with different geographical scopes.