Publications

This paper presents a new Fuel Cell Fuel Consumption Minimization Strategy (FCFCMS) for Hybrid Electric Vehicles (HEVs) powered by a fuel cell and an energy storage system in order to minimize as much as possible the consumption of hydrogen while maintaining the State Of Charge (SOC) of the battery. Compared to existing Energy Management Strategies (EMSs) (such as the well-known State Machine Strategy (SMC) Fuzzy Logic Control (FLC) Frequency Decoupling and FLC (FDFLC) and the Equivalent Consumption Minimization Strategy (ECMS)) the proposed strategy increases the overall vehicle energy efficiency and therefore minimizes the total hydrogen consumption while respecting the constraints of each energy and power element. A model of a hybrid vehicle has been built using the TruckMaker/MATLAB software. Using the Urban Dynamometer Driving Schedule (UDDS) which includes several stops and accelerations the performance of the proposed strategy has been compared with these different approaches (SMC FLC FDFLC and ECMS) through several simulations.

Ignition conditions and risks of ignition on a permissible value of hydrogen concentration in purge gas prescribed by HFCV-GTR were reevaluated. Experiments were conducted to investigate burning behavior and thermal influence of continuous evacuation of hydrogen under continuous purge of air / hydrogen premixed gas which is close to an actual purge condition of FCV and thermal evacuation of hydrogen. As a result of the re-evaluation it was shown from the viewpoint of safety that the permissible value of hydrogen concentration in purge gas prescribed by the current HFCV GTR is appropriate.

Worldwide the road transport sector typically arises as one of the main sources of air pollutants due to its high energy intensity and the use of fossil fuels. Thus governments and social agents work on the development and prospective planning of decarbonisation strategies oriented towards sustainable transport. In this regard the increase in the use of alternative fuels is the recurrent approach to energy planning e.g. through the promotion of electric vehicles biofuels natural gas liquefied petroleum gas etc. However there is a lack of comprehensive information on the techno-economic performance of production pathways for alternative fuels. The acquisition of robust techno-economic data is still a challenge for energy planners modellers analysts and policy-makers when building their prospective models to support decision-making processes. Hence this article aims to fill this gap through a deep literature review including the most representative production routes for a wide range of road transportation fuels. This led to the development of datasets including investment costs operating and maintenance costs and transformation efficiencies for more than 40 production pathways. The techno-economic data presented in this work are expected to be especially useful to those energy actors interested in performing long-term studies on the transition to a sustainable transport system.

Hydrogen has emerged as an important part of the clean energy mix needed to ensure a sustainable future. Falling costs for hydrogen produced with renewable energy combined with the urgency of cutting greenhouse-gas emissions has given clean hydrogen unprecedented political and business momentum.



This paper from the International Renewable Energy Agency (IRENA) examines the potential of hydrogen fuel for hard-to-decarbonise energy uses including energy-intensive industries trucks aviation shipping and heating applications. But the decarbonisation impact depends on how hydrogen is produced. Current and future sourcing options can be divided into grey (fossil fuel-based) blue (fossil fuel-based production with carbon capture utilisation and storage) and green (renewables-based) hydrogen. Green hydrogen produced through renewable-powered electrolysis is projected to grow rapidly in the coming years.



Among other findings:



Important synergies exist between hydrogen and renewable energy. Hydrogen can boost renewable electricity market growth and broaden the reach of renewable solutions.

• Electrolysers can add demand-side flexibility. In advanced European energy markets electrolysers are growing from megawatt to gigawatt scale.
• Blue hydrogen is not inherently carbon free. This type of production requires carbon-dioxide (CO2) monitoring verification and certification.
• Synergies may exist between green and blue hydrogen deployment given the chance for economies of scale in hydrogen use or logistics.
• A hydrogen-based energy transition will not happen overnight. Hydrogen use is likely to catch on for specific target applications. The need for new supply infrastructure could limit hydrogen use to countries adopting this strategy.
• Dedicated hydrogen pipelines have existed for decades and could be refurbished along with existing gas pipelines. The implications of replacing gas abruptly or changing mixtures gradually should be further explored.

Trade of energy-intensive commodities produced with hydrogen including “e-fuels” could spur faster uptake or renewables and bring wider economic benefits.

This report shows that low-carbon hydrogen supply at scale is economically and environmentally feasible and will have significant societal benefits if the right localised approach and best-practices for production are used. The report also demonstrates that there is not one single hydrogen production pathway to achieve low lifecycle greenhouse gas (GHG) emissions but rather the need for a fact-based approach that leverages regional resources and includes a combination of different production pathways. This will achieve both emission and cost reductions ultimately helping to decarbonize the energy system and limit global warming.

In 2020 more than 15 countries launched major hydrogen plans and policies and industry players announced new projects of more than 35GW until 2030. As this hydrogen momentum accelerates it is increasingly clear that decision makers must put the focus on decarbonization to ensure hydrogen can fulfil its potential as a key solution in the global clean energy transition making a significant contribution to net zero emissions. To support this effort the two-part Hydrogen Council report provides new data based on an assessment of the GHG emissions generated through different hydrogen supply pathways and the lifecycle GHG emissions for different hydrogen applications (see report part 1 – A Life-cycle Assessment). In addition the report explores 3 hypothetical hydrogen supply scenarios to measure the feasibility and impact of deploying renewable and low-carbon hydrogen at scale (report part 2 – Potential Supply Scenarios).

The report outlines that there are many ways of producing hydrogen and although GHG emissions vary widely very high CO2 savings can be achieved across a broad range of different hydrogen production pathways and end-uses. For example while “green” hydrogen produced through water electrolysis with renewable power achieves the lowest emissions “blue” hydrogen produced from natural gas with high CO2 capture rate and storage can also achieve low emissions if best technologies are used and best practices are followed. Across eight illustrative pathways explored in the report analysis shows that if hydrogen is used significant GHG emission reductions can be made: as much as 60-90% or more compared to conventional fossil alternatives. The study also looked into the gross water demand of hydrogen supply pathways. Water electrolysis has a very low specific water demand of 9 kg per kg of hydrogen compared to cooling of thermal power plants (hundreds of kg/kg) or biomass cultivation (hundreds to thousands of kg/kg).

Furthermore low-carbon hydrogen supply at scale is fully achievable. Having investigated two hypothetical boundary scenarios (a “green-only” and a “blue-only” scenario) to assess the feasibility and impact of decarbonized hydrogen supply the report found that both scenarios are feasible: they are not limited by the world’s renewables potential or carbon sequestration (CCS) capacities and they do not exceed the speed at which industry can scale. In the Hydrogen Council’s “Scaling up” study a demand of 21800 TWh hydrogen has been identified for the year 2050. To achieve this a compound annual growth rate of 30-35% would be needed for electrolysers and CCS. This deployment rate is in line with the growth of the offshore wind and solar PV industry over the last decade.

Hydrogen Council data released in January 2020 showed that a wide range of hydrogen applications can become competitive by 2030 driven also by falling costs of renewable and low-carbon hydrogen[1]. The new study indicates that a combination of “green” and “blue” production pathways would lead to hydrogen cost reductions relative to either boundary scenario. By making use of the near-term cost advantage of “blue” while also scaling up “green” hydrogen as the most cost-efficient option in many regions in the medium and long-term the combined approach lowers average hydrogen costs between now and 2050 relative to either boundary scenario.

Part 1 – A Life-cycle Assessment

• The life-cycle assessment (LCA) analysis in this study addresses every aspect of the supply chain from primary energy extraction to end use. Eight primary-energy-to-hydrogen value chains have been selected for illustrative purposes.
• Across the hydrogen pathways and applications depicted very high to high GHG emission reduction can be demonstrated using green (solar wind) and blue hydrogen.
• In the LCA study renewables + electrolysis shows strongest GHG reduction of the different hydrogen supply pathways assessed in this study with a best-case blue hydrogen pathway also coming into the same order of magnitude.

Part 2 – Potential Supply Scenarios

• Currently the vast majority of hydrogen is produced by fossil pathways. To achieve a ten-fold build-out of hydrogen supply by 2050 as envisaged by the Hydrogen Council in its ‘Scaling Up’ report (2017) the existing use of hydrogen – and all its many potential new roles – need to be met by decarbonized sources.
• Three hypothetical supply scenarios with decarbonized hydrogen sources are considered in the study: 1) a “green-only” renewables-based world; 2) a “blue-only” world relying on carbon sequestration; and 3) a combined scenario that uses a region-specific combination of green and blue hydrogen based on the expected regional cost development of each source.
• The study finds that a decarbonized hydrogen supply is possible regardless of the production pathway: while both the green and blue boundary scenario would be highly ambitious regarding the required speed of scale-up they do not exceed the world’s resources on either renewable energy or carbon sequestration capabilities.
• A combination of production pathways would result in the least-cost global supply over the entire period of scale-up. It does so by making best use of the near-term cost advantage of “blue” in some regions while simultaneously achieving a scale-up in electrolysis.
• In reality the decarbonized supply scenario will combine a range of different renewable and low-carbon hydrogen production pathways that are optimally suited to local conditions political and societal preferences and regulations as well as industrial and cost developments for different technologies.

You can download the full reports from the Hydrogen Council website

Hydrogen Council Report- Decarbonization Pathways Part 1: Life Cycle Assessment here

Hydrogen Council Report-Decarbonization Pathways Part 2: Supply Scenarios here

An executive summary of the whole project can be found here

Car park fires are known to be dangerous due to the risk of fast fire spread from one car to another. In general no fatalities are recorded in such fires but they may have a great cost in relation to damaged cars and structural repair. A very recent example is the Liverpool multi-storey car park fire from December 31 2017. It destroyed 1400 cars and parts of the building structure collapsed. This questions the validity of current design praxis of car parks. Literature studies assumes a 12 minutes period for the fire spread from one gasoline fuelled car to another. Statistical research and test from the European commission of steel structures states that in an open car park at most 3-4 vehicles are expected to be on fire at the same time.<br/>A number of investigations have been made concerning vehicles performance in car park fires but only a few are concerned with hydrogen-fuelled vehicles (HFV). It is therefore important to investigate how these new vehicles may contribute to potential fire spread scenario. The aim of the paper is to report the outcome of car park fire spread simulations involving common fuelled and hydrogen fuelled cars. The case study is based on a typical car park found in Denmark. The simulation applied numerical models implemented in the Fire Dynamic Simulator (FDS). In particular the focus of the study is on the influence of the parking distance to fire spread to adjacent vehicles in case a TPRD is activated during a car fire. The results help understanding whether different design rules should be envisaged for such structures or how a sufficient safety level can be obtained by ensuring specific parking condition for the hydrogen-fuelled cars.

Thermal power plants face substantial challenges to remain competitive in energy systems with high shares of variable renewables especially inflexible integrated gasification combined cycles (IGCC). This study addresses this challenge through the integration of Gas Switching Combustion (GSC) and Membrane Assisted Water Gas Shift (MAWGS) reactors in an IGCC plant for flexible electricity and/or H₂ production with inherent CO₂ capture. When electricity prices are high H₂ from the MAWGS reactor is used for added firing after the GSC reactors to reach the high turbine inlet temperature of the H-class gas turbine. In periods of low electricity prices the turbine operates at 10% of its rated power to satisfy the internal electricity demand while a large portion of the syngas heating value is extracted as H₂ in the MAWGS reactor and sold to the market. This product flexibility allows the inflexible process units such as gasification gas treating air separation unit and CO2 compression transport and storage to operate continuously while the plant supplies variable power output. Two configurations of the GSC-MAWGS plant are presented. The base configuration achieves 47.2% electric efficiency and 56.6% equivalent hydrogen production efficiency with 94.8–95.6% CO₂ capture. An advanced scheme using the GSC reduction gases for coal-water slurry preheating and pre-gasification reached an electric efficiency of 50.3% hydrogen efficiency of 62.4% and CO₂ capture ratio of 98.1–99.5%. The efficiency is 8.4%-points higher than the pre-combustion CO₂ capture benchmark and only 1.9%-points below the unabated IGCC benchmark.

The large-scale storage of hydrogen plays a fundamental role in a potential future hydrogen economy. Although the storage of gaseous hydrogen in salt caverns already is used on a full industrial scale the approach is not applicable in all regions due to varying geological conditions. Therefore other storage methods are necessary. In this article options for the large-scale storage of hydrogen are reviewed and compared based on fundamental thermodynamic and engineering aspects. The application of certain storage technologies such as liquid hydrogen methanol ammonia and dibenzyltoluene is found to be advantageous in terms of storage density cost of storage and safety. The variable costs for these high-density storage technologies are largely associated with a high electricity demand for the storage process or with a high heat demand for the hydrogen release process. If hydrogen is produced via electrolysis and stored during times of low electricity prices in an industrial setting these variable costs may be tolerable.

Our gas network is one of the best developed in the world providing safe secure affordable energy to homes and businesses across the UK.<br/><br/>To meet the biggest energy challenge of our generation – making deep cuts to carbon emissions by 2050 – it needs to embrace new technology which builds on these strengths and delivers the integrated flexible network of the future. This briefing sets out how it is already doing that. Take a look at our Gas Futures Messages booklet attached.

As hydrogen-air mixtures are flammable in a wide range of concentrations and the minimum ignition energy is low compared to hydrocarbon fuels the safe handling of hydrogen is of utmost importance. Additional hazards may arise with the accidental spill of liquid hydrogen. Such a release of LH2 leads to a formation of a cryogenic pool a dynamic vaporization process and consequently a dispersion of gaseous hydrogen into the environment. Several LH2 release experiments as well as modelling approaches address this phenomenology. In contrast to existing approaches a new CFD model capable of simulating liquid and gaseous distribution was developed at Forschungszentrum Jülich. It is validated against existing experiments and yields no substantial lacks in the physical model and reveals a qualitatively consistent prediction. Nevertheless the deviation between experiment and simulation raises questions on the completeness of the database in particular with regard to the boundary conditions and available measurements.