Publications

Decarbonisation will need a significant societal shift. The when why and how we travel is going to look very different within a decade. Joining us is Florentine Roy – a leading expert on electric vehicles and Innovation Project Lead at UK Power Networks and Matt Hindle - Head of Net Zero and Sustainability at Wales and West Utilities. Let’s talk about the energy system implications of this massive undertaking and how it can be enabled by innovation in a fair and just way.

The podcast can be found here.

This briefing considers the opportunities and challenges associated with the manufacture and future use of zero-carbon ammonia which is referred to in this report as green ammonia. The production of green ammonia has the capability to impact the transition towards zero-carbon through the decarbonisation of its current major use in fertiliser production. Perhaps as significantly it has the following potential uses: • As a medium to store and transport chemical energy with the energy being released either by directly reacting with air or by the full or partial decomposition of ammonia to release hydrogen. • As a transport fuel by direct combustion in an engine or through chemical reaction with oxygen in the air in a fuel cell to produce electricity to power a motor. • To store thermal energy through the absorption of water and through phase changes between material states (for example liquid to gas).

This review critically analyses various aspects of the most promising thermochemical cycles for clean hydrogen production. While the current hydrogen market heavily relies on fossil-fuel-based platforms the thermochemical water-splitting systems based on the reduction-oxidation (redox) looping reactions have a significant potential to significantly contribute to the sustainable production of green hydrogen at scale. However compared to the water electrolysis techniques the thermochemical cycles suffer from a low technology readiness level (TRL) which retards the commercial implementation of these technologies. This review mainly focuses on identifying the capability of the state-of-the-art thermochemical cycles to deploy large-scale hydrogen production plants and their techno-economic performance. This study also analyzed the potential integration of the hybrid looping systems with the solar and nuclear reactor designs which are evidenced to be more cost-effective than the electrochemical water-splitting methods but it excludes fossil-based thermochemical processes such as gasification steam methane reforming and pyrolysis. Further investigation is still required to address the technical issues associated with implementing the hybrid thermochemical cycles in order to bring them to the market for sustainable hydrogen production.

The NEWGASMET project has the overall objective to increase knowledge about the accuracy and durability of commercially available gas meters after exposure to renewable gases. This should lead to the improvement of existing meter designs and flow calibration standards. One of the recently released results is a proposal for a set of test gases to represent the range of non-conventional gases in the scope of the revision of the gas meter standards. In details these were proposed to be used in the CEN/TC237 standards and the OIML-R137:2014. During the project meetings concerns have been raised regarding the applicability of such test gases to EMC tests for static meters. Today such tests are performed in air but there is a clear agreement that the behaviour of the meter during EMC tests can be influenced by the renewable gas type. At least this agreement exists for the ultrasonic measurement technology while further discussion might be needed for the mass flow. However it is not simply possible to redesign the current EMC tests by replacing air with the defined gas mixtures as this would be quite impractical especially considering the explosive nature of the test gases.

An under-expanded hydrogen jet from high-pressure equipment or storage tank is a potential incident scenario. Experiments demonstrated that the delayed ignition of a highly turbulent under-expanded hydrogen jet generates a blast wave able to harm people and damage property. There is a need for engineering tools to predict the pressure effects during such incidents to define hazard distances. The similitude analysis is applied to build a correlation using available experimental data. The dimensionless blast wave overpressure generated by delayed ignition and the follow-up deflagration or detonation of hydrogen jets at an any location from the jet ∆Pexp/P0 is correlated to the original dimensionless parameter composed of the product of the dimensionless ratio of storage pressure to atmospheric pressure Ps/P0 and the ratio of the jet release nozzle diameter to the distance from the centre of location of the fast-burning near-stoichiometric mixture on the jet axis (30% of hydrogen in the air by volume) to the location of a target (personnel or property) d/Rw. The correlation is built using the analysis of 78 experiments regarding this phenomenon in the wide range of hydrogen storage pressure of 0.5–65.0 MPa and release diameter of 0.5–52.5 mm. The correlation is applicable to hydrogen free jets at ambient and cryogenic temperatures. It is found that the generated blast wave decays inversely proportional to the square of the distance from the fast-burning portion of the jet. The correlation is used to calculate the hazard distances by harm thresholds for five typical hydrogen applications. It is observed that in the case of a vehicle with onboard storage tank at pressure 70 MPa the “no-harm” distance for humans reduces from 10.5 m to 2.6 m when a thermally activated pressure relief device (TPRD) diameter decreases from 2 mm to a diameter of 0.5 mm.

The effort to meet the ambitious targets of the Paris agreement is challenging many governments. The US and UK governments might have different approaches to achieving the targets but both will rely heavily on renewable energy sources such as wind and solar to power their economies. However these sources of power are unpredictable and ways will have to be developed to store renewable energy for hours days weeks seasons and maybe even years before it is used. As the disruptive and increasingly deadly impacts of climate change are being felt across the world the need to move to more sustainable sources of energy and to identify viable ways to store that energy has never been more important.<br/>This was the subject of the US–UK Science Forum on electrical storage in support of the grid which was held online from 17 – 18 March 2021. Co-organised by the Royal Society and the National Academy of Sciences it brought together a diverse group of 60 scientists policy makers industry leaders regulators and other key stakeholders for a wide-ranging discussion on all aspects of energy storage from the latest research in the field to the current status of deployment. It also considered the current national and international economic and policy contexts in which these developments are taking place. A number of key points emerged from the discussion. First it is clear that renewable energy will play an increasingly important role in the US and UK energy systems of the future and energy storage at a multi-terawatt hour scale has a vital role to play. Of course this will evolve differently to some extent in both countries and elsewhere according to the various geographical technological economic political social and regulatory environments. Second international collaboration is critical – no single nation will solve this problem alone. As two of the world’s leading scientific nations largest economies and per capita CO2 emitters with a long track record of collaboration the US and UK are well placed to play a vital role in addressing this critical challenge. As the discussion highlighted a wide range of energy storage technologies are now emerging and becoming increasingly available many of which have the potential to be critical components of a future net-zero energy system. A crucial next phase is in ensuring that these are technically developed as well as economically and political viable. This will require the support of a wide range of these potential solutions to ensure that their benefits remain widely available and to avoid costly ‘lock-in’. Scientists and science academies have a critical role to play in analysing technology options their combinations and their potential roles in future sustainable energy systems and in working with policymakers to incentivise investment and deployment.

This episode examines how we are tackling a sustainable future – with Net Zero hurtling towards us at great pace. We’re around a year on from the pledges made at COP26 the UK’s Green Recovery initiative is well under way and by next year Britain is aiming to blend up to 20 per cent hydrogen into its gas networks. So now is the time to continue to unlock new insight and understand further the realities of both the challenges and opportunities ahead.

The podcast can be found here.

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

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

The paper provides an economic model for the assessment of hydrogen production at the site of an existing thermal power plant which is then integrated into the existing gas grid. The model uses projections of electricity prices natural gas prices and CO2 prices as well as estimates of the cost of building a power-to-gas system for a 25-year period. The objective of this research is to calculate the yellow hydrogen production price for each lifetime year of the Power-to-gas system to evaluate yellow hydrogen competitiveness compared to the fossil alternatives. We test if an incentive scheme is needed to make this technology economically viable. The research also provides several sensitivity scenarios of electricity natural gas and CO2 price changes. Our research results clearly prove that yellow hydrogen is not yet competitive with fossil alternatives and needs incentive mechanisms for the time being. At given natural gas and CO2 prices the incentive for hydrogen production needs to be 52.90 EUR/MWh in 2025 and 36.18 EUR/MWh in 2050. However the role of hydrogen in the green transition could be very important as it provides ancillary services and balances energy sources in the power system.

During the fast-filling of a high-pressure hydrogen tank the temperature of hydrogen would rise significantly and may lead to failure of the tank. In addition the temperature rise also reduces hydrogen density in the tank which causes mass decrement into the tank. Therefore it is of practical significance to study the temperature rise and the amount of charging of hydrogen for hydrogen safety. In this paper the change of hydrogen temperature in the tank according to the pressure rise during the process of charging the high-pressure tank in the process of a 82-MPa hydrogen filling system the final temperature the amount of filling of hydrogen gas and the change of pressure of hydrogen through the pressure reducing valve and the performance of heat exchanger for cooling high-temperature hydrogen were analyzed by theoretical and numerical methods. When high-pressure filling began in the initial vacuum state the condition was called the “First cycle”. When the high-pressure charging process began in the remaining condition the process was called the “Second cycle”. As a result of the theoretical analysis the final temperatures of hydrogen gas were calculated to be 436.09 K for the first cycle of the high-pressure tank and 403.55 for the second cycle analysis. The internal temperature of the buffer tank increased by 345.69 K and 32.54 K in the first cycle and second cycles after high-pressure filling. In addition the final masses were calculated to be 11.58 kg and 12.26 kg for the first cycle and second cycle of the high-pressure tank respectively. The works of the paper can provide suggestions for the temperature rise of 82 MPa compressed hydrogen storage system and offer necessary theory and numerical methods for guiding safe operation and construction of a hydrogen filling system.

There is increasing interest in migrating to a carbon-neutral power system that relies on renewable energy due to concerns about greenhouse gas emissions energy shortages and global warming. However the increasing share of renewable energy has added volatility and uncertainty to power system operations. Introducing new devices and using flexible resources may help solve the problem but expanding the domain of the problem can be another solution. Sector coupling which integrates production consumption conversion and storage by connecting various energy domains could potentially meet the needs of each energy sector. It can also reduce the generation of surplus energy and unnecessary carbon emissions. As a result sector coupling an integrated energy system increases the acceptance of renewable energy in the traditional power system and makes it carbon neutral. However difficulties in large-scale integration low conversion efficiency and economic feasibility remain obstacles. This perspective paper discusses the background definition and components of sector coupling as well as its functions and examples in rendering power systems carbon-neutral. The current limitations and outlook of sector coupling are also examined.

Reducing the carbon emissions from trucks is critical to achieving the carbon peak of road freight. Based on the prediction of truck population and well-to-wheel (WTW) emission analysis of traditional diesel trucks and potential clean trucks including natural gas battery-electric plug-in hybrid electric and hydrogen fuel cell the paper analyzed the total greenhouse gas (GHG) emissions of China's road freight under four scenarios including baseline policy facilitation (PF) technology breakthrough (TB) and PF-TB. The truck population from 2021 to 2035 is predicted based on regression analysis by selecting the data from 2002 to 2020 of the main variables such as the GDP scale road freight turnover road freight volume and the number of trucks. The study forecasts the truck population of different segments such as mini-duty trucks (MiDT) light-duty trucks (LDT) medium-duty trucks (MDT) and heavy-duty trucks (HDT). Relevant WTW emissions data are collected and adopted based on the popular truck in China's market PHEVs have better emission intensity especially in the HDT field which reduces by 51% compared with ICEVs. Results show that the scenario of TB and PF-TB can reach the carbon peak with 0.13% and 1.5% total GHG emissions reduction per year. In contrast the baseline and PF scenario fail the carbon peak due to only focusing on the number of clean trucks while lacking the restrictions on the GHG emission factors of energy and ignoring the improvement of trucks' energy efficiency and the total emissions increased by 29.76% and 16.69% respectively compared with 2020. As the insights adopting clean trucks has an important but limited effect which should coordinate with the transition to low carbon energy and the melioration of clean trucks to reach the carbon peak of road freight in China.

We had investigated feasible measures to reduce CO2 emission and came to conclusion that introduction of new fuel such as hydrogen with near zero CO2 emission is required for achieving Japan’s commitment of 80% CO2 reduction by 2050. Under this background we are proposing and aiming to realize “CO2 free hydrogen chain” utilizing Australian brown coal linked with CCS. In this chain hydrogen produced from brown coal is liquefied and transported to Japan by liquid hydrogen carrier. We have conducted feasibility study of commercial scale “CO2 free hydrogen chain” whose result shows the chain is technically and economically feasible.

Currently renewable energy-based generators are considered worldwide to achieve net zero targets. However the stochastic nature of renewable energy systems leads to regulation and control challenges for power system operators especially in remote and regional grids with smaller footprints. A hybrid system (i.e. solar wind biomass energy storage) could minimise this issue. Nevertheless the hybrid system is not possible to develop in many islands due to the limited land area geographical conditions and others. Hydrogen as a carrier of clean energy can be used in locations where the installation of extensive or medium-scale renewable energy facilities is not permissible due to population density geographical constraints government policies and regulatory issues. This paper presents a techno-economic assessment of designing a green hydrogen-based microgrid for a remote island in North-east Australia. This research work determines the optimal sizing of microgrid components using green hydrogen technology. Due to the abovementioned constraints the green hydrogen production system and the microgrid proposed in this paper are located on two separate islands. The paper demonstrates three cost-effective scenarios for green hydrogen production transportation and electricity generation. This work has been done using Hybrid Optimisation Model for Multiple Energy Resources or HOMER Pro simulation platform. Simulation results show that the Levelized Cost of Energy using hydrogen technology can vary from AU$0.37/kWh to AU$1.08/kWh depending on the scenarios and the variation of key parameters. This offers the potential to provide lower-cost electricity to the remote community. Furthermore the CO2 emission could be reduced by 1760777 kg/year if the renewable energy system meets 100% of the electricity demand. Additionally the sensitivity analysis in this paper shows that the size of solar PV and wind used for green hydrogen production can further be reduced by 50%. The sensitivity analysis shows that the system could experience AU$0.03/kWh lower levelized cost if the undersea cable is used to transfer the generated electricity between islands instead of hydrogen transportation. However it would require environmental approval and policy changes as the islands are located in the Great Barrier Reef.

The transformation of hydrogen metallurgy is a principal means of promoting the iron and steel industry (ISI) in reaching peak and deep emissions reduction. However the environmental impact of different hydrogen production paths on hydrogen metallurgy has not been systemically discussed. To address this gap based on Long-range Energy Alternatives Planning System (LEAP) this paper constructs a bottom-up energy system model that includes hydrogen production iron and steel (IS) production and power generation. By setting three hydrogen production structure development paths namely the baseline scenario business-as-usual (BAU) scenario and clean power (CP) scenario the carbon dioxide (CO2) emissions impact of different hydrogen production paths on hydrogen metallurgy is carefully evaluated from the perspective of the whole industry and each IS production process. The results show that under the baseline scenario the hydrogen metallurgy transition will help the CO2 emissions of ISI peak at 2.19 billion tons in 2024 compared to 2.08 billion tons in 2020 and then gradually decrease to 0.78 billion tons in 2050. However different hydrogen production paths will contribute to the reduction or inhibit the reduction. In 2050 the development of electrolysis hydrogen production with renewable electricity will reduce CO2 emissions by an additional 48.76 million tons (under the CP scenario) while the hydrogen production mainly based on coal gasification and methane reforming will increase the additional 50.04 million tons CO2 emissions (under the BAU scenario). Moreover under the hydrogen production structure relying mainly on fossil and industrial by-products the technological transformation of blast furnace ironmaking with hydrogen injections will leak carbon emissions to the upstream energy processing and conversion process. Furthermore except for the 100% scrap based electric arc furnace (EAF) process the IS production process on hydrogen-rich shaft furnace direct reduced iron (hydrogen-rich DRI) have lower CO2 emissions than other processes. Therefore developing hydrogen-rich DRI will help the EAF steelmaking development to efficiently reduce CO2 emissions under scrap constraints.

Worldwide energy systems are experiencing a transition to more sustainable systems. According to the Hydrogen Roadmap Europe (FCH EU 2019) hydrogen will play an important role in future energy systems due to its ability to support sustainability goals and will account for approximately 13% of the total energy mix in the coming future. Correct hydrogen supply chain (HSC) planning is therefore vital to enable a sustainable transition. However due to the operational characteristics of the HSC its planning is complicated. Renewable hydrogen supply can be diverse: Hydrogen can be produced de-centrally with renewables such as wind and solar energy or centrally by using electricity generated from a hydro power plant with a large volume. Similarly demand for hydrogen can also be diverse with many new applications such as fuels for fuel cell electrical vehicles and electricity generation feedstocks in industrial processes and heating for buildings. The HSC consists of various stages (production storage distribution and applications) in different forms with strong interdependencies which further increase HSC complexity. Finally planning of an HSC depends on the status of hydrogen adoption and market development and on how mature technologies are and both factors are characterised by high uncertainties. Directly adapting the traditional approaches of supply chain planning for HSCs is insufficient. Therefore in this study we develop a planning matrix with related planning tasks leveraging a systematic literature review to cope with the characteristics of HSCs. We focus only on renewable hydrogen due to its relevance to the future low-carbon economy. Furthermore we outline an agenda for future research from the supply chain management perspective in order to support HSC development considering the different phases of HSCs adoption and market development.

A steady state analysis method was developed for gas networks with distributed injection of alternative gas. A low pressure gas network was used to validate the method. Case studies were carried out with centralized and decentralized injection of hydrogen and upgraded biogas. Results show the impact of utilizing a diversity of gas supply sources on pressure distribution and gas quality in the network. It is shown that appropriate management of using a diversity of gas supply sources can support network management while reducing carbon emissions.

Due to the increasing greenhouse gas emissions as well as due to the rapidly increasing use of renewable energy sources in the electricity generation over the last years interest in hydrogen is rising again. Hydrogen can be used as a storage for renewable energy balancing the whole energy systems and contributing to the decarbonization of the energy system especially of the industry and the transport sector. The major objective of this paper is to discuss various ways of hydrogen production depending on the primary energy sources used. Moreover the economic and environmental performance of three major hydrogen colors as well as major barriers for faster deployment in fuel cell vehicles are analyzed. The major conclusion is that the full environmental benefits of hydrogen use are highly dependent on the hydrogen production methods and primary sources used. Only green hydrogen with electricity from wind PV and hydro has truly low emissions. All other sources like blue hydrogen with CCUS or electrolysis using the electricity grid have substantially higher emissions coming close to grey hydrogen production. Another conclusion is that it is important to introduce an international market for hydrogen to lower costs and to produce hydrogen where conditions are best. Finally the major open question remaining is whether e including all external costs of all energy carriers hydrogen of any color may become economically competitive in any sector of the energy system. The future success of hydrogen is very dependent on technological development and resulting cost reductions as well as on future priorities and the corresponding policy framework. The policy framework should support the shift from grey to green hydrogen.

The publication gives an overview of the production costs of synthetic methane in a Power-to-Gas process. The production costs depend in particularly on the electricity price and the full load hours of the plant sub-systems electrolysis and methanation. The full-load hours of electrolysis are given by the electricity supply concept. In order to increase the full-load hours of methanation the size of the intermediate hydrogen storage tank and the size of the methanation are optimised on the basis of the availability of hydrogen. The calculation of the production costs for synthetic methane are done with economics for 2030 and 2050 and the expenditures are calculated for one year of operation. The sources of volume of purchased electricity are the short-term market long-term contracts direct-coupled renewable energy sources or seasonal use of surpluses. Gas sales are either traded on the short-term market or guaranteed by long-term contracts. The calculations show that an intermediate storage tank for hydrogen adjustment of the methanation size and operating electrolysis and methanation separately increase the workload of the sub-system methanation. The gas production costs can be significantly reduced. With the future expected development of capital expenditures operational expenditure electricity prices gas costs and efficiencies an economic production of synthetic natural gas for the years 2030 especially for 2050 is feasible. The results show that Power-to-Gas is an option for long-term large-scale seasonal storage of renewable energy. Especially the cases with high operating hours for the sub-system methanation and low electricity prices show gas production costs below the expected market prices for synthetic gas and biogas.

International ships carrying liquefied fuel are strongly recommended to install vent masts to control the pressure of cargo tanks in the event of an emergency. However the gas emitted from a vent mast may be hazardous for the crew of the ship. In the present study the volume and length of the flammable zone (FZ) created by the emitted gas above the ship was examined. Various scenarios comprising four parameters namely relative wind speed arrangement of vent masts combination of emissions among four vent masts and direction of emission from the vent-mast outlet were considered. The results showed that the convection acts on the volume and length of an FZ. The volume of an FZ increases when there is a reduction in convection reaching the FZ and when strong convection brings hydrogen from a nearby FZ. The length of the FZ is also related to convection. An FZ is elongated if the center of a vortex is located inside the FZ because this vortex traps hydrogen inside the FZ. The length of an FZ decreases if the center of the vortex is located outside the FZ as such a vortex brings more fresh air into the FZ.

This week we have Christopher Jackson in the hot seat as he catches up with BayoTech CEO Mo Vargas and BayoTech’s new President Michael Koonce to discuss the acquisition of IGX Group. Mergers & Acquisition activity has been growing in the hydrogen space with commentators suggesting the market is maturing faster than expected and customers seeking more integrated solutions. In this episode we look at the IGX acquisition by BayoTech and ask why the deal made sense what it means for the market and other participants and what listeners can learn from the deal to foreshadow future activity.

The podcast can be found on their website

With COP starting this week we discuss with the HLC team the role of hydrogen in decarbonization and the critical need for hydrogen to scale quickly. Andrew and Patrick sit down with Kieran Coleman Energy & Industry Lead for the United Nations COP High Level Champions to chat about the work being done in advance of COP with partners and the level of ambition we’ve seen across various sectors about the future of hydrogen and a lot more!

The podcast can be found on their website

As transitioning away from fossil fuels to renewable energy sources comes on the agenda for a range of energy systems energy modelling tools can provide useful insights. If large parts of the energy system turns out to be based on variable renewables an accurate representation of their short-term variability in such models is crucial. In this paper we have developed a stochastic long-term energy model and applied it to an isolated Arctic settlement as a challenging and realistic test case. Our findings suggest that the stochastic modelling approach is critical in particular for studies of remote Arctic energy systems. Furthermore the results from a case study of the Norwegian settlement of Longyearbyen suggest that transitioning to a system based on renewable energy sources is feasible. We recommend that a solution based mainly on renewable power generation but also including energy storage import of hydrogen and adequate back-up capacity is taken into consideration when planning the future of remote Arctic settlements.

The aim of this study is to identify the technical solution space for future fully renewable energy systems that stays within a sustainable biomass demand. In the transition towards non-fossil energy and material systems biomass is an attractive source of carbon for those demands that also in the non-fossil systems depend on high density carbon containing fuels and feedstocks. However extensive land use is already a sustainability challenge and an increase in future demands threat to exceed global sustainable biomass potentials which according to an international expert consensus is around 10 – 30 GJ/person/year in 2050. Our analytical review of 16 scenarios from 8 independent studies of fully renewable energy system designs and synthesis of 9 generic system designs reveals the significance of the role of electrification and hydrogen integration for building a fully renewable energy system which respects the global biomass limitations. The biomass demand of different fully renewable energy system designs was found to lie in the range of 0 GJ/person/year for highly integrated electrified pure electro-fuel scenarios with up to 25 GJ/person/year of hydrogen to above 200 GJ/person/year for poorly integrated full bioenergy scenarios with no electrification or hydrogen integration. It was found that a high degree of system electrification and hydrogen integration of at least 15 GJ/person/year is required to stay within sustainable biomass limits.

This work studies the development of a sustainable hydrogen infrastructure that supports the transition towards a low-carbon transport system in the United Kingdom (UK). The future hydrogen demand is forecasted over time using a logistic diffusion model which reaches 50% of the market share by 2070. The problem is solved using an extension of SHIPMod an optimisation-based framework that consists of a multi-period spatially-explicit mixed-integer linear programming (MILP) formulation. The optimisation model combines the infrastructure elements required throughout the different phases of the transition namely economies of scale road and pipeline transportation modes and carbon capture and storage (CCS) technologies in order to minimise the present value of the total infrastructure cost using a discounted cash-flow analysis. The results show that the combination of all these elements in the mathematical formulation renders optimal solutions with the gradual infrastructure investments over time required for the transition towards a sustainable hydrogen economy.

Hydrogen production and refueling integrated station can play an important role in the development of hydrogen transportation and fuel cell vehicles and actively promote the energy transformation. By using DC system for hydrogen production and refueling the conversion links can be reduced and the system efficiency can be effectively improved. In this paper a new scheme of DC interconnection for hydrogen production and refueling integrated station is proposed and the modular modeling and operation capability evaluation method are proposed including the characteristic analysis of integrated station the modular modeling and evaluation method for multiple integrated stations under DC interconnection. The DC interconnection system of five integrated stations is constructed and operation capability improvement of integrated stations after adopting the innovative DC interconnection scheme is analyzed. On this basis the system simulation model based on MATLAB/Simulink and physical test platform are built to verify the effectiveness of the theoretical analysis.

Concerning off-grid areas diesel engines still dominate the scene of local electricity generation despite the related pollution concerns and high operating costs. There is thus a huge global potential in remote areas for exploiting local renewable energy sources (RES) in place of fossil generation. Energy storage systems become hence essential for off-grid communities to cope with the issue of RES intermittency allowing them to rely on locally harvested RES. In this work we analysed different typologies of off-grid renewable power systems involving batteries and hydrogen as means to store energy to find out which is the most cost-effective configuration in remote areas. Both Li-ion and lead-acid batteries were included in the analysis and both alkaline and PEM electrolysis technologies were considered for the production of hydrogen. Starting from single cell electrochemical models the performance curves of the electrolyser and fuel cell devices were derived for a more detailed techno-economic assessment. Lifetimes of batteries and H2-based components were also computed based on how the power-to-power (P2P) system operates along the reference year. The particle swarm optimization (PSO) algorithm was employed to find the component sizes that allow minimizing the levelized cost of energy (LCOE) while keeping the off-grid area energy autonomous. As a case study the Ginostra village on the island of Stromboli (North of Sicily Southern Italy) was analysed since it is well representative of small insular locations in the Mediterranean area. The renewable P2P solution (0.51 €/kWh for the cheapest configuration) was found to be economically preferable than the current existing power system relying on diesel generators (0.86 €/kWh). Hydrogen in particular can prevent the oversizing of both battery and PV systems thus reducing the final cost of electricity delivered by the P2P system. Moreover unlike diesel generators the RES-based configuration allows avoiding the production of local air pollutants and GHG emissions during its operation.

Many energy system optimization studies show that hydrogen may be an important part of an optimal decarbonisation mix but such analyses are unable to examine the uncertainties associated with breaking the ‘locked-in’ nature of incumbent systems. Uncertainties around technical learning rates; consumer behaviour; and the strategic interactions of governments automakers and fuel providers are particularly acute. System dynamics and agent-based models and studies of historical alternative fuel transitions have furthered our understanding of possible transition dynamics but these types of analysis exclude broader systemic issues concerning energy system evolution (e.g. supplies and prices of low-carbon energy) and the politics of transitions. This paper presents a hybrid approach to assessing hydrogen transitions in the UK by linking qualitative scenarios with quantitative energy systems modelling using the UK MARKAL model. Three possible transition pathways are explored each exploring different uncertainties and possible decision points with modelling used to inform and test key elements of each scenario. The scenarios draw on literature review and participatory input and the scenario structure is based on archetypal transition dynamics drawn from historical energy system transitions reflecting insights relating to innovation system development and resistance to change. Conclusions are drawn about appropriate policy responses.

Green hydrogen is a key solution for reducing CO2 emissions in various industrial applications but high production costs continue to hinder its market penetration today. Better competitiveness is linked to lower investment costs and higher efficiency of the conversion technologies among which polymer electrolyte membrane electrolysis seems to be attractive. Although new manufacturing techniques and materials can help achieve these goals a less frequently investigated approach is the optimization of the design point and operating strategy of electrolyzers. This means in particular that the questions of how often a system should be operated and which cell voltage should be applied must be answered. As existing techno-economic models feature gaps which means that these questions cannot be adequately answered a modified model is introduced here. In this model different technical parameters are implemented and correlated to each other in order to simulate the lowest possible levelized cost of hydrogen and extract the required designs and strategies from this. In each case investigated the recommended cost-based cell voltage that should be applied to the system is surprisingly low compared to the assumptions made in previous publications. Depending on the case the cell voltage is in a range between 1.6 V and 1.8 V with an annual operation of 2000e8000 h. The wide range of results clearly indicate how individual the design and operation must be but with efficiency gains of several percent the effect of optimization will be indispensable in the future.

This article aims to develop a proton exchange membrane (PEM) electrolyzer emulator. This emulator is realized through an equivalent electrical scheme. It allows taking into consideration the dynamic operation of PEM electrolyzers which is generally neglected in the literature. PEM electrolyzer dynamics are reproduced by the use of supercapacitors due to the high value of the equivalent double-layer capacitance value. Steady-state and dynamics operations are investigated in this work. The design criteria are addressed. The PEM electrolyzer emulator is validated by using a 400-W commercial PEM electrolyzer. This emulator is conceived to test new DC-DC converters to supply the PEM ELs and their control as well avoiding the risk to damage a real electrolyzer for experiment purposes. The proposed approach is valid both for a single cell and for the whole stack emulation.

Bi-directional solid oxide cell systems (Bi-SOC) are being increasingly considered as an electrical energy storage method and consequently as a means to boost the penetration of renewable energy (RE) and to improve the grid flexibility by power-to-gas electrochemical conversion. A major advantage of these systems is that the same SOC stack operates as both energy storage device (SOEC) and energy producing device (SOFC) based on the energy demand and production. SOEC and SOFC systems are now well-optimised as individual systems; this work studies the effect of using the bi-directionality of the SOC at a system level. Since the system performance is highly dependent on the cell-stack operating conditions this study improves the stack parameters for both operation modes. Moreover the year-round cumulative exergy method (CE) is introduced in the solid oxide cell (SOC) context for estimating the system exergy efficiencies. This method is an attempt to obtain more insightful exergy assessments since it takes into account the operational hours of the SOC system in both modes. The CE method therefore helps to predict more accurately the most efficient configuration and operating parameters based on the power production and consumption curves in a year. Variation of operating conditions configurations and SOC parameters show a variation of Bi-SOC system year-round cumulative exergy efficiency from 33% to 73%. The obtained thermodynamic performance shows that the Bi-SOC when feasible can prove to be a highly efficient flexible power plant as well as an energy storage system.

Regarding the problem of hydrogen diffusion of the fuel cell vehicle (HFCV) when its hydrogen supply system leaks this research uses the FLUENT software to simulate numerical values in the process of hydrogen leakage diffusion in both open space and closed space. This paper analyzed the distribution range and concentration distribution characteristics of hydrogen in these two different spaces. Besides this paper also took a survey about the effects of leakage rate wind speed wind direction in open space and the role the air vents play on hydrogen safety in closed space which provides a reference for the hydrogen safety of HFCV. In conclusion the experiment result showed that: In open space hydrogen leakage rate has a great influence on its diffusion. When the leakage rate doubles the hydrogen leakage range will expand about 1.5 times simultaneously. The hydrogen diffusion range is the smallest when the wind blows at 90 degrees which is more conducive to hydrogen diffusion. However when the wind direction is against the direction of the leakage of hydrogen the range of hydrogen distribution is maximal. Under this condition the risk of hydrogen leakage is highest. In an enclosed space when the vent is set closest to the leakage position the volume fraction of hydrogen at each time is smaller than that at other positions so it is more beneficial to safety.

This is the inaugural episode of the EAH: Deep Dive podcast mini-series! Our first episode features the co-founders of Enapter Vaitea Cowan and Jan Justus-Schmidt. Enapter is a young company that has made a big splash in the hydrogen space with their modular scalable AEM electrolyzer technology. Last year they made headlines with their successful public offering on the DAX and the company is expected to be a the forefront of the hydrogen sector again in 2021 as they begin construction of their mass production facility in Germany and announce the upcoming Generation Hydrogen event on May 19 2021.

The podcast can be found on their website

HarmonHy is a European Union-funded Specific Support Action aiming to make an assessment of the activities on hydrogen and fuel cell regulations codes and standards (RCS) on a worldwide level. On this basis gaps have been identified and potential conflicts between regulations codes and standards have been investigated. Types of document to be referred to include international regional and national standards EU directives UNECE regulations… Particular attention will be paid to the identification of the needs for standards as perceived by the industry as well as to actions aiming to ensure concordance between standards codes and regulations. Standards and regulations require harmonization. HarmonHy pursues the elaboration of an action plan and a roadmap for future work on harmonizing regulations codes and standards on hydrogen and fuel cells on an international level.

Research into novel internal combustion engines requires consideration of the diversity in future fuels in an attempt to reduce drastically CO2 emissions from vehicles and promote energy sustainability. Hydrogen has been proposed as a possible fuel for future internal combustion engines and can be produced from renewable sources. Hydrogen’s wide flammability range allows higher engine efficiency than conventional fuels with both reduced toxic emissions and no CO2 gases. Most previous work on hydrogen engines has focused on spark-ignition operation. The current paper presents results from an optical study of controlled autoignition (or homogeneous charge compression ignition) of hydrogen in an engine of latest spark-ignition pentroof combustion chamber geometry with direct injection of hydrogen (100 bar). This was achieved by a combination of inlet air preheating in the range 200–400 C and residual gas recirculated internally by negative valve overlap. Hydrogen fuelling was set to various values of equivalence ratio typically in the range / = 0.40–0.63. Crank-angle resolved flame chemiluminescence images were acquired for a series of consecutive cycles at 1000 RPM in order to calculate in-cylinder rates of flame expansion and motion. Planar Laser Induced Fluorescence (LIF) of OH was also applied to record more detailed features of the autoignition pattern. Single and double (i.e. ‘split’ per cycle) hydrogen injection strategies were employed in order to identify the effect of mixture preparation on autoignition’s timing and spatial development. An attempt was also made to review relevant in-cylinder phenomena from the limited literature on hydrogen-fuelled spark-ignition optical engines and make comparisons were appropriate.

Demands for space and water heating constitute a significant proportion of the total energy demands in Great Britain and are predominantly satisfied through natural gas which makes the heat sector a large emitter of carbon dioxide. Renewable hydrogen which can be injected into the gas grid or used directly in processes for generating heat and/or electricity is being considered as a low-carbon alternative energy carrier to natural gas because of its suitability for large-scale long- and short-term storage and low transportation losses all of which help to overcome the intermittency and seasonal variations in renewables. This requires new infrastructures for production storage transport and utilisation of renewable hydrogen – a hydrogen value chain – the design of which involves many interdependent decisions such as: where to locate wind turbines; where to locate electrolysers close to wind generation or close to demands; whether to transport energy as electricity or hydrogen and how; where to locate storage facilities; etc. This paper presents the Value Web Model a novel and comprehensive spatio-temporal mixed-integer linear programming model that can simultaneously optimise the design planning and operation of integrated energy value chains accounting for short-term dynamics inter-seasonal storage and investments out to 2050. It was coupled with GIS modelling to identify candidate sites for wind generation and used to optimise a number of scenarios for the production of hydrogen from onshore and offshore wind turbines in order to satisfy heat demands. The results show that over a wide range of scenarios the optimal pathway to heat is roughly 20% hydrogen and 80% electricity. Hydrogen storage both in underground caverns and pressurised tanks is a key enabling technology.

Hydrogen produced from biomass is an alternative energy source to fossil fuels. In this study hydrogen production by gasification of the banana plant is proposed. A fixed-bed catalytic reactor was designed considering fluidization conditions and a height/diameter ratio of 3/1. Experimentation was carried out under the following conditions: 368 ◦C atmospheric pressure 11.75 g of residual mass of the banana (pseudo-stem) an average particle diameter of 1.84 mm and superheated water vapor as a gasifying agent. Gasification reactions were performed using a catalyzed and uncatalyzed medium to compare the effectiveness of each case. The catalyst was Ni/Al2O3 synthesized by coprecipitation. The gas mixture produced from the reaction was continuously condensed to form a two-phase liquid–gas system. The synthesis gas was passed through a silica gel filter and analyzed online by gas chromatography. To conclude the results of this study show production of 178 mg of synthesis gas for every 1 g of biomass and the selectivity of hydrogen to be 51.8 mol% when a Ni 2.5% w/w catalyst was used. The amount of CO2 was halved and CO was reduced from 3.87% to 0% in molar percentage. Lastly a simulation of the distribution of temperatures inside the furnace was developed; the modeled behavior is in agreement with experimental observations.

To accelerate clean energy transition China has explored the potential of hydrogen as an energy carrier since 2001. Until 2020 49 national hydrogen policies were enacted. This paper explores the relevance of these policies to the development of the hydrogen industry and energy transition in China. We examine the reasons impacts and challenges of Chinese national hydrogen policies through the conceptual framework of Thomas Dye’s policy analysis method and the European Training Foundation’s policy analysis guide. This research provides an ex‐post analysis for previous policies and an ex‐ante analysis for future options. We argue that the energy supply revolution and energy technology revolution highlight the importance of hydrogen development in China. Particularly the pressure of the automobile industry transition leads to experimentation concerning the application of hydrogen in the transportation sector. This paper also reveals that hydro‐ gen policy development coincides with an increase in resource input and has positive spill over effects. Furthermore we note that two challenges have impeded progress: a lack of regulations for the industry threshold and holistic planning. To address these challenges the Chinese government can design a national hydrogen roadmap and work closely with other countries through the Belt and Road Initiative.

The use of hydrogen storage tanks at 100% of nominal working pressure NWP is expected only after refuelling. Driving between refuellings is characterised by the state of charge SoC<100%. There is experimental evidence that Type IV tanks tested in a fire at initial pressures below one-third of its NWP depending on a fire source were leaking without rupture. This paper aims at understanding this phenomenon and the development of a predictive model. The numerical research has demonstrated that the heat transfer from fire through the composite overwrap is sufficient to melt the polymer liner. This initiates hydrogen microleaks through the composite wall before it loses the load-bearing ability when the resin degrades deep enough to cause the tank to rupture. The dependence of tank fire-resistance rating (FRR) on the SoC is presented for tanks of volume in the range 36-244 L. The tank wall thickness non-uniformity i.e. thinner composite at the dome area is identified as a serious issue for tank’s fire resistance that must be addressed by tank manufacturers and OEMs. The effect of the burst pressure ratio on FRR is investigated. It is concluded that thermal parameters of the composite wall i.e. decomposition heat and temperatures play a vital role in simulations of tank failure and thus FRR.

The production and application of hydrogen an environmentally friendly energy source have been attracting increasing interest of late. Although steam methane reforming (SMR) method is used to produce hydrogen it is difficult to build a high-fidelity model because the existing equation-oriented theoretical model cannot be used to clearly understand the heat-transfer phenomenon of a complicated reforming reactor. Herein we developed an artificial neural network (ANN)-based data-driven model using 485710 actual operation datasets for optimizing the SMR process. Data preprocessing including outlier removal and noise filtering was performed to improve the data quality. A model with high accuracy (average R2 = 0.9987) was developed which can predict six variables through hyperparameter tuning of a neural network model as follows: syngas flow rate; CO CO2 CH4 and H2 compositions; and steam temperature. During optimization the search spaces for nine operating variables namely the natural gas flow rate for the feed and fuel hydrogen flow rate for desulfurization water flow rate and temperature air flow rate SMR inlet temperature and pressure and low-temperature shift (LTS) inlet temperature were defined and applied to the developed model for predicting the thermal efficiencies for 387420489 cases. Subsequently five constraints were established to consider the feasibility of the process and the decision variables with the highest process thermal efficiency were determined. The process operating conditions showed a thermal efficiency of 85.6%.

The use of hydrogen as energy carrier in a low emission microturbine could be an interesting option for renewable energy storage distributed generation and combined heat & power. However the hydrogen using in gas turbine is limited by the NOx emissions and the difficulty to operate safely. CFD simulations represent a powerful and mature tool to perform detailed 3-D investigation for the development of a prototype before carrying out an experimental analysis. This paper describes the CFD supported redesign of the Turbec T100 microturbine combustion chamber natural gas-fired to allow the operation on 100% hydrogen.

Hydrogen-microvoid interactions were studied via unit cell analyses with different hydrogen concentrations. The absolute failure strain decreases with hydrogen concentration but the failure loci were found to follow the same trend dependent only on stress triaxiality in other words the effects of geometric constraint and hydrogen on failure are decoupled. Guided by the decoupling principle a hydrogen informed Gurson model is proposed. This model is the first practical hydrogen embrittlement simulation tool based on the hydrogen enhanced localized plasticity (HELP) mechanism. It introduces only one additional hydrogen related parameter into the Gurson model and is able to capture hydrogen enhanced internal necking failure of microvoids with accuracy; its parameter calibration procedure is straightforward and cost efficient for engineering purpose

In the context of the great research pulse on clean energy transition distributed energy systems have a key role especially in the case of integration of both renewable and traditional energy sources. The stable interest in small-scale gas turbines can further increase owing to their flexibility in both operation and fuel supply. Since their not-excellent electrical efficiency research activities on micro gas turbine (MGT) are focused on the performance improvements that are achievable in several ways like modifying the Brayton cycle integrating two or more plants using cleaner fuels. Hence during the last decades the growing interest in MGT-based energy systems encouraged the development of many numerical approaches aimed to provide a reliable and effective prediction of the energy systems’ behavior. Indeed numerical modeling can help to individuate potentialities and issues of each enhanced layout or hybrid energy system and this review aims to discuss the various layout solutions proposed by researchers with particular attention to recent publications highlighting the adopted modeling approaches and methods.

As one kind of clean zero carbon and sustainable energy hydrogen energy has been regarded as the most potential secondary energy. Recently hydrogen refueling station gradually becomes one of important distribution infrastructures that provides hydrogen sources for transport vehicles and other distribution devices. However the highly combustible nature of hydrogen may bring great hazards to environment and human. The safety design of hydrogen usage has been brought to public too. This paper is mainly focused on the hydrogen leakage and dispersion process. A new solver for gaseous buoyancy dispersion process is developed based on OpenFOAM [1]. Thermodynamic and transport properties of gases are updated by library Mutation ++ [2]. For validation two tests of hydrogen dispersion in partially opened space and closed space are presented. Numerical simulation of hydrogen dispersion behavior in hydrogen refueling station is carried out in this paper as well. From the results three phases of injection dispersion and buoyancy can be seen clearly. The profile of hydrogen concentration is tend to be Gaussian in dispersion region. Subsonic H2 jet in stagnant environment is calculated for refueling station the relationship between H2 concentration decay and velocity along the jet trajectory is obtained.

The optimal sizing of stand-alone renewable H2-based microgrids requires the load demand to be reliably satisfied by means of local renewable energy supported by a hybrid battery/hydrogen storage unit while minimizing the system costs. However this task is challenging because of the high number of components that have to be installed and operated. In this work an MILP optimization framework has been developed and applied to the off-grid village of Ginostra (on the Stromboli island Italy) which is a good example of several other insular sites throughout the Mediterranean area. A year-long time horizon was considered to model the seasonal storage which is necessary for off-grid areas that wish to achieve energy independence by relying on local renewable sources. The degradation costs of batteries and H2-based devices were included in the objective function of the optimization problem i.e. the annual cost of the system. Efficiency and investment cost curves were considered for the electrolyzer and fuel cell components in order to obtain a more detailed and precise techno-economic estimation. The design optimization was also performed with the inclusion of a general demand response program (DRP) to assess its impact on the sizing results. Moreover the effectiveness of the proposed MILP-based method was tested by comparing it with a more traditional approach based on a metaheuristic algorithm for the optimal sizing complemented with ruled-based strategies for the system operation. Thanks to its longer-term storage capability hydrogen is required for the optimal system configuration in order to reach energy self-sufficiency. Finally considering the possibility of load deferral the electricity generation cost can be reduced to an extent that depends on the amount of load that is allowed to participate in the DRP scheme. This cost reduction is mainly due to the decreased capacity of the battery storage system.

The existing combustion-centered energy mix in Malaysia has shown that replacing fossil fuels with zero-carbon alternative fuels could be a better approach to achieve the reduction of the carbon footprint of the power generation industry. In this study the potential of zero-carbon alternative fuels generated from renewable sources such as green hydrogen and green ammonia was addressed in terms of the production transport storage and utilization in Malaysia’s thermal power plants. The updated developments associated to green hydrogen and green ammonia across the globe have also been reviewed to support the existing potential in Malaysia. Though green hydrogen and green ammonia are hardly commercialized in Malaysia for the time being numerous potentialities have been identified in utilizing these fuels to achieve the zero-carbon power generation market in Malaysia. The vast and strategic location of natural gas network in Malaysia has the potential to deliver green hydrogen with minimal retrofitting required. Moreover there are active participation of Malaysia’s academic institutions in the development of water electrolysis that is the core process to convert the electricity from renewables plant into hydrogen. Malaysia also has the capacity to use its abundance of depleted gas reservoirs for the storage of green hydrogen. A large number of GT plants in Malaysia would definitely have the potential to utilize hydrogen co-firing with natural gas to minimize the amount of carbon dioxide (CO2) released. The significant number of ammonia production plants in Malaysia could provide a surplus of ammonia to be used as an alternative fuel for power plants. With regard to the energy policy in Malaysia positive acceptance of the implementation of renewable energy has been shown with the introduction of various energy policies aimed at promoting the incorporation of renewables into the energy mix. However there is still inadequate support for the implementation of alternative zero-carbon fuels in Malaysia.

Hydrogen is regarded as a promising fuel in the transition to clean energy. Nevertheless as the demand for hydrogen increases some microgrids equipped with P2H (MGH) will encounter the issue of primary energy deficiency. Meanwhile some microgrids (MGs) face the difficulty of being unable to consume surplus energy locally. Hence we interconnect MGs with different energy characteristics and then establish a collaborative scheduling model of multi-microgrids (MMGs). In this model a federated demand response (FDR) program considering predictive mean voting is designed to coordinate controllable loads of electricity heat and hydrogen in different MGs. With the coordination of FDR the users’ satisfaction and comfort in each MG are kept within an acceptable range. To further adapt to an actual working condition of the microturbine (MT) in MGH a power interaction method is proposed to maintain the operating power of the MT at the optimum load level and shave peak and shorten the operating periods of MT. In the solution process the sequence operation theory is utilized to deal with the probability density of renewable energy. A series of case studies on a test system of MMG demonstrate the effectiveness of the proposed method.

Green Print -  Future Heat for Everyone draws together technical consumer and economic considerations to create a pioneering plan to transition 22 million UK homes to low carbon heat by 2050.<br/>Our Green Print underlines the scale of the challenge ahead acknowledging that a mosaic of low carbon heating solutions will be required to meet the needs of individual communities and setting out 12 key steps that can be taken now in order to get us there<br/>The Climate Change Committee (CCC) estimates an investment spend of £250bn to upgrade insulation and heating in homes as well as provide the infrastructure to deliver the energy.<br/>This is a task of unprecedented scale the equivalent of retro-fitting 67000 homes every month from now until 2050. In this Report Cadent takes the industry lead in addressing the challenge.

A district heating system is an eco-friendly power generation facility with high energy efficiency. The boiler water wall tube used in the district heating system is exposed to extremely harsh conditions and unexpected fractures often occur during operation. In this study a corrosion failure analysis of the boiler water wall tube was performed to elucidate the failure mechanisms. The study revealed that overheating by flames was the cause of the failure of the boiler water wall tube. With an increase in temperature in a localized region the microstructure not only changed from ferrite/pearlite to martensite/bainite which made it more susceptible to brittleness but it also developed tensile residual stresses in the water-facing side by generating cavities or microcracks along the grain boundaries inside the tube. High-temperature hydrogen embrittlement combined with stress corrosion cracking initiated many microcracks inside the tube and created an intergranular fracture.