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Hydrogen vs. Battery in the Long-term Operation. A Comparative Between Energy Management Strategies for Hybrid Renewable Microgrids
Apr 2020
Publication
The growth of the world’s energy demand over recent decades in relation to energy intensity and demography is clear. At the same time the use of renewable energy sources is pursued to address decarbonization targets but the stochasticity of renewable energy systems produces an increasing need for management systems to supply such energy volume while guaranteeing at the same time the security and reliability of the microgrids. Locally distributed energy storage systems (ESS) may provide the capacity to temporarily decouple production and demand. In this sense the most implemented ESS in local energy districts are small–medium-scale electrochemical batteries. However hydrogen systems are viable for storing larger energy quantities thanks to its intrinsic high mass-energy density. To match generation demand and storage energy management systems (EMSs) become crucial. This paper compares two strategies for an energy management system based on hydrogen-priority vs. battery-priority for the operation of a hybrid renewable microgrid. The overall performance of the two mentioned strategies is compared in the long-term operation via a set of evaluation parameters defined by the unmet load storage efficiency operating hours and cumulative energy. The results show that the hydrogen-priority strategy allows the microgrid to be led towards island operation because it saves a higher amount of energy while the battery-priority strategy reduces the energy efficiency in the storage round trip. The main contribution of this work lies in the demonstration that conventional EMS for microgrids’ operation based on battery-priority strategy should turn into hydrogen-priority to keep the reliability and independence of the microgrid in the long-term operation.
Economic Value of Flexible Hydrogen-based Polygeneration Energy Systems
Jan 2016
Publication
Polygeneration energy systems (PES) have the potential to provide a flexible high-efficiency and low-emissions alternative for power generation and chemical synthesis from fossil fuels. This study aims to assess the economic value of fossil-fuel PES which rely on hydrogen as an intermediate product. Our analysis focuses on a representative PES configuration that uses coal as the primary energy input and produces electricity and fertilizer as end-products. We derive a series of propositions that assess the cost competitiveness of the modeled PES under both static and flexible operation modes. The result is a set of metrics that quantify the levelized cost of hydrogen the unit profit-margin of PES and the real option values of ‘diversification’ and ‘flexibility’ embedded in PES. These metrics are subsequently applied to assess the economics of Hydrogen Energy California (HECA) a PES currently under development in California. Under our technical and economic assumptions HECA’s levelized cost of hydrogen is estimated at 1.373 $/kgh. The profitability of HECA as a static PES increases in the share of hydrogen converted to fertilizer rather than electricity. However when configured as a flexible PES HECA almost breaks even on a pre-tax basis. Diversification and flexibility are valuable for HECA when polygeneration is compared to static monogeneration of electricity but these two real options have no value when comparing polygeneration to static monogeneration of fertilizers.
Two-Dimensional Photocatalysts for Energy and Environmental Applications
Jun 2022
Publication
The depletion of fossil fuels and onset of global warming dictate the achievement of efficient technologies for clean and renewable energy sources. The conversion of solar energy into chemical energy plays a vital role both in energy production and environmental protection. A photocatalytic approach for H2 production and CO2 reduction has been identified as a promising alternative for clean energy production and CO2 conversion. In this process the most critical parameter that controls efficiency is the development of a photocatalyst. Two-dimensional nanomaterials have gained considerable attention due to the unique properties that arise from their morphology. In this paper examples on the development of different 2D structures as photocatalysts in H2 production and CO2 reduction are discussed and a perspective on the challenges and required improvements is given.
Everything About Hydrogen Podcast: Toyota's global hydrogen ambitions
Feb 2020
Publication
On this weeks episode the team are talking all things hydrogen with Craig Scott the Group Manager for Toyota North America a global automotive giant and a recognised pioneer in the field of fuel cell mobility. On the show we get into the story of Toyota’s roll out of fuel cell mobility solutions in North America the challenges and opportunities that fuel cell vehicles can offer in the hydrogen market and the challenges around infrastructure. Importantly we also dive into the scaling up work that Toyota is undertaking and some of its plans for next steps on the mission to become the world’s leader in fuel cell mobility solutions. All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
Everything About Hydrogen Podcast: Taking the Lead in the Hydrogen Economy
Sep 2021
Publication
On the season premier episode the EAH hosts are joined by the Governor of New Mexico Michelle Lujan Grisham. The State of New Mexico has the opportunity to lead the United States into the hydrogen era and the Governor and her team are poised to take the opportunity to make New Mexico the strategic center of the US hydrogen economy. The Governor is joined by New Mexico Environment Department Secretary James Kenney on the show to announce the forthcoming New Mexico Hydrogen Hub Act which her administration expects to drive investment in the state job growth in the energy sector and catapult New Mexico to top of the list of states driving the hydrogen revolution.
The podcast can be found on their website.
The podcast can be found on their website.
Comparing e-Fuels and Electrification for Decarbonization of Heavy-Duty Transports
Oct 2022
Publication
The freight sector is expected to keep or even increase its fundamental role for the major modern economies and therefore actions to limit the growing pressure on the environment are urgent. The use of electricity is a major option for the decarbonization of transports; in the heavy-duty segment it can be implemented in different ways: besides full electric-battery powertrains electricity can be used to supply catenary roads or can be chemically stored in liquid or gaseous fuels (e-fuels). While the current EU legislation adopts a tailpipe Tank-To-Wheels approach which results in zero emissions for all direct uses of electricity a Well-To-Wheels (WTW) method would allow accounting for the potential benefits of using sustainable fuels such as e-fuels. In this article we have performed a WTW-based comparison and modelling of the options for using electricity to supply heavy-duty vehicles: e-fuels eLNG eDiesel and liquid Hydrogen. Results showed that the direct use of electricity can provide high Greenhouse Gas (GHG) savings and also in the case of the e-fuels when low-carbonintensity electricity is used for their production. While most studies exclusively focus on absolute GHG savings potential considerations of the need for new infrastructures and the technological maturity of some options are fundamental to compare the different technologies. In this paper an assessment of such technological and non-technological barriers has been conducted in order to compare alternative pathways for the heavy-duty sector. Among the available options the flexibility of using drop-in energy-dense liquid fuels represents a clear and substantial immediate advantage for decarbonization. Additionally the novel approach adopted in this paper allows us to quantify the potential benefits of using e-fuels as chemical storage able to accumulate electricity from the production peaks of variable renewable energies which would otherwise be wasted due to grid limitations.
A Review of Renewable Hydrogen Generation and Proton Exchange Membrane Fuel Cell Technology for Sustainable Energy Development
Mar 2023
Publication
Beyond its typical usage as an economical fuel for creating ammonia methanol and petroleum refineries hydrogen has become a modern form of energy. Energy-scarce advanced countries like Japan and Korea are concerned about energy privacy and environmental responsibility. Many wealthy countries have been fervently building hydrogen networks and renewable energy sources to fulfil their main goals or the growing requirement for energy. In this study we concentrate on proton-exchange membrane fuel cells (PEMFCs) generally viewed as financially viable for vehicle industries especially for automobiles demanding less hydrogen infrastructure facilities like fleets of cabs buses and logistical automobiles. This overview includes all of the significant PEMFC components focusing on the reaction gas diffusion and polymer. Without question the equipment necessary for a consistent supply of ultra-pure hydrogen is essential for the effectiveness of PEMFC in extensive requests.
Behavior of Barrier Wall under Hydrogen Storage Tank Explosion with Simulation and TNT Equivalent Weight Method
Mar 2023
Publication
Hydrogen gas storage place has been increasing daily because of its consumption. Hydrogen gas is a dream fuel of the future with many social economic and environmental benefits to its credit. However many hydrogen storage tanks exploded accidentally and significantly lost the economy infrastructure and living beings. In this study a protection wall under a worst-case scenario explosion of a hydrogen gas tank was analyzed with commercial software LS-DYNA. TNT equivalent method was used to calculate the weight of TNT for Hydrogen. Reinforced concrete and composite protection wall under TNT explosion was analyzed with a different distance of TNT. The initial dimension of the reinforced concrete protection wall was taken from the Korea gas safety code book (KGS FP217) and studied the various condition. H-beam was used to make the composite protection wall. Arbitrary-Lagrangian-Eulerian (ALE) simulation from LS-DYNA and ConWep pressure had a good agreement. Used of the composite structure had a minimum displacement than a normal reinforced concrete protection wall. During the worst-case scenario explosion of a hydrogen gas 300 kg storage tank the minimum distance between the hydrogen gas tank storage and protection wall should be 3.6 m.
Spherically Expanding Flame Simulations in Cantera Using a Lagrangian Formulation
Sep 2021
Publication
A Lagrangian-based one-dimensional approach has been developed using Cantera to study the dynamics of spherically expanding flames. The detailed reaction model USC-Mech II has been employed to examine flame propagating in hydrogen-air mixtures. In the first part our approach has been validated against laminar flame speed and Markstein number data from the literature. It was shown that the laminar flame speed was predicted within 5% on average but that discrepancies were observed for the Markstein number especially for rich mixtures. In the second part a detailed analysis of the thermo-chemical dynamics along the path of Lagrangian particles propagating in stretched flames was performed. For mixtures with negative Markstein lengths it was found that at high stretch rates the mixture entering the reaction-dominated period is less lean with respect to the initial mixture than at low stretch rate. This induces a faster rate of chemical heat release and of active radical production which results in a higher flame propagation speed. Opposite effects were observed for mixtures with positive Markstein lengths for which slower flame propagation was observed at high stretch rates compared to low stretch rates."
Simulation and Study of PEMFC System Directly Fueled by Ammonia Decomposition Gas
Mar 2022
Publication
Ammonia can be stored as a liquid under relatively easy conditions (Ambient temperature by applying 10 bar or Ambient pressure with the temperature of 239 K). At the same time liquid ammonia has a high hydrogen storage density and is therefore a particularly promising carrier for hydrogen storage. At the same time the current large-scale industrial synthesis of ammonia has long been mature and in the future it will be possible to achieve a zero-emission ammonia regeneration cycle system by replacing existing energy sources with renewable ones. Ammonia does not contain carbon and its use in fuel cells can avoid NOx production during energy release. high temperature solid oxide fuel cells can be directly fueled by ammonia and obtain good output characteristics but the challenges inherent in high temperature solid oxide fuel cells greatly limit the implementation of this option. Whereas PEMFC has gained initial commercial use however for PEMFC ammonia is a toxic gas so the general practice is to convert ammonia to pure hydrogen. Ammonia to hydrogen requires decomposition under high temperature and purification which increases the complexity of the fuel system. In contrast PEMFC that can use ammonia decomposition gas directly can simplify the fuel system and this option has already obtained preliminary experimental validation studies. The energy efficiency of the system obtained from the preliminary validation experiments is only 34–36% which is much lower than expected. Therefore this paper establishes a simulation model of PEMFC directly using ammonia decomposition gas as fuel to study the maximum efficiency of the system and the effect of the change of system parameters on the efficiency and the results show that the system efficiency can reach up to 45% under the condition of considering certain heat loss. Increasing the ammonia decomposition reaction temperature decreases the system efficiency but the effect is small and the system efficiency can reach 44% even at a temperature of 850°C. The results of the study can provide a reference for a more scientific and quantitative assessment of the potential value of direct ammonia decomposition gas-fueled PEMFC.
The Role of Clean Hydrogen Value Chain in a Successful Energy Transition of Japan
Aug 2022
Publication
The clean hydrogen in the prioritized value chain platform could provide energy incentives and reduce environmental impacts. In the current study strengths weaknesses opportunities and threats (SWOT) analysis has been successfully applied to the clean hydrogen value chain in different sectors to determine Japan’s clean hydrogen value chain’s strengths weaknesses opportunities and threats as a case study. Japan was chosen as a case study since we believe that it is the only pioneer country in that chain with a national strategy investments and current projects which make it unique in this way. The analyses include evaluations of clean energy development power supply chains regional energy planning and renewable energy development including the internal and external elements that may influence the growth of the hydrogen economy in Japan. The ability of Japan to produce and use large quantities of clean hydrogen at a price that is competitive with fossil fuels is critical to the country’s future success. The implementation of an efficient carbon tax and carbon pricing is also necessary for cost parity. There will be an increasing demand for global policy coordination and inter-industry cooperation. The results obtained from this research will be a suitable model for other countries to be aware of the strengths weaknesses opportunities and threats in this field in order to make proper decisions according to their infrastructures potentials economies and socio-political states in that field.
H-Mat Hydrogen Compatibility of NBR Elastomers
Sep 2021
Publication
The H2@Scale program of the U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office (HFTO) is supporting work on the hydrogen compatibility of polymers to improve the durability and reliability of materials for hydrogen infrastructure. The hydrogen compatibility program (H-Mat) seeks “to address the challenges of hydrogen degradation by elucidating the mechanisms of hydrogen-materials interactions with the goal of providing science-based strategies to design materials (micro)structures and morphology with improved resistance to hydrogen degradation.” Previous work on ethylene propylene diene indicated hydrogen interaction with plasticizer increased its migration to the surface and coalescing within the elastomer compound. New research on nitrile butadiene (NBR) has found hydrogen and pressure interactions with a series model rubber-material compounds to behave similarly in some compounds and improved in other compounds that is demonstrated through volume change and compression-set differences in the materials. Further studies were conducted using a helium-ion microscope (HeIM) which revealed significant morphological changes in the plasticizer-incorporating compounds after static exposure and pressure cycling as evidenced by time-of-flight secondary ion mass spectrometry. Additional studies using x-ray chromatography revealed that more micro-voids/-cracks developed after gas decompression in unfilled materials than in filled materials; transmission electron microscopy (TEM) probed at the nano-meter level showing change in filler distribution and morphology around Zinc-based particles.
Machine Learning Approach for Prediction of Hydrogen Environment Embrittlement in Austenitic Steels
Jun 2022
Publication
This study introduces a machine learning approach to predict the effect of alloying elements and test conditions on the hydrogen environment embrittlement (HEE) index of austenitic steels for the first time. The correlation between input features and the HEE index was analyzed with Pearson's correlation coefficient (PCC) and Maximum Information Coefficient (MIC) algorithms. The correlation analysis results identified Ni and Mo as dominant features influencing the HEE index of austenitic steels. Based on the analysis results the performance of the four representative machine learning models as a function of the number of top-ranked features was evaluated: random forest (RF) linear regression (LR) Bayesian ridge (BR) and support vector machine (SVM). Regardless of the type and the number of top-ranking features the RF model had the highest accuracy among various models. The machine learning-based approach is expected to be useful in designing new steels having mechanical properties required for hydrogen applications.
Assessment of Paper Industry Decarbonization Potential via Hydrogen in a Multi-energy System Scenario: A Case Study
Jul 2023
Publication
Green hydrogen is currently regarded as a key catalyst for the decarbonization of energy-intensive industries. In this context the pulp and paper industry stands out as one of the most demanding given the simultaneous need for large amounts of heat and electricity usually satisfied via cogeneration systems. Given the urgent need for cost-effective solutions in response to the climate crisis it is crucial to analyze the feasibility of retrofitting existing power plants to operate carbon-neutral. The aim of this work is to provide a techno-economic analysis for the conversion of a conventional cogeneration system to run on locally produced hydrogen. Building on the energy consumption of the paper mill the operation of a hydrogen-fuelled gas turbine is modelled in detail. Based on these results a multi-energy system model for the production of green fuel is presented considering production via solar-powered PEM electrolyzers storage in tanks and final use in the gas turbine. An optimal configuration for the system is defined leading to the definition of a solution that ensures a cost of 6.41 /kg for the production of green hydrogen. Finally a sensitivity analysis highlights the close dependence of the economic profitability of the Power-to-X system on the natural gas price. The results indicate that although positive performance is achieved the cost of investment remains still prohibitive for systems of this size and the high initial capital expenditure needs to be supported by incentive policies that facilitate the adoption of hydrogen in industrial applications making it competitive in the short term.
Hydrogenerally - Episode 8: Hydrogen for Combustion
Jan 2023
Publication
In this episode Steffan Eldred Hydrogen Knowledge Transfer Manager and Debra Jones Chemistry Knowledge Transfer Manager from Innovate UK KTN talk about hydrogen combustion with special guest Duncan Engeham European Research and Development Director at Cummins Inc.
The podcast can be found on their website.
The podcast can be found on their website.
Everything About Hydrogen Podcast: Reaching for the Stars
Mar 2023
Publication
Today Everything About Hydrogen had a chance to speak with Paul Barrett the CEO of Hysata and dig into what makes this electrolysis company different.
The podcast can be found on their website.
The podcast can be found on their website.
Hydrogen-Powered Aviation—Design of a Hybrid-Electric Regional Aircraft for Entry into Service in 2040
Mar 2023
Publication
Over the past few years the rapid growth of air traffic and the associated increase in emissions have created a need for sustainable aviation. Motivated by these challenges this paper explores how a 50-passenger regional aircraft can be hybridized to fly with the lowest possible emissions in 2040. In particular the use of liquid hydrogen in this aircraft is an innovative power source that promises to reduce CO2 and NOx emissions to zero. Combined with a fuel-cell system the energy obtained from the liquid hydrogen can be used efficiently. To realize a feasible concept in the near future considering the aspects of performance and security the system must be hybridized. In terms of maximized aircraft sustainability this paper analyses the flight phases and ground phases resulting in an aircraft design with a significant reduction in operating costs. Promising technologies such as a wingtip propeller and electric green taxiing are discussed in this paper and their potential impacts on the future of aviation are highlighted. In essence the hybridization of regional aircraft is promising and feasible by 2040; however more research is needed in the areas of fuel-cell technology thermal management and hydrogen production and storage.
Hydrogen Fuel Cell Power System—Development Perspectives for Hybrid Topologies
Mar 2023
Publication
In recent years the problem of environmental pollution especially the emission of greenhouse gases has attracted people’s attention to energy infrastructure. At present the fuel consumed by transportation mainly comes from fossil energy and the strong traffic demand has a great impact on the environment and climate. Fuel cell electric vehicles (FCEVs) use hydrogen energy as a clean alternative to fossil fuels taking into account the dual needs of transportation and environmental protection. However due to the low power density and high manufacturing cost of hydrogen fuel cells their combination with other power supplies is necessary to form a hybrid power system that maximizes the utilization of hydrogen energy and prolongs the service life of hydrogen fuel cells. Therefore the hybrid power system control mode has become a key technology and a current research hotspot. This paper first briefly introduces hydrogen fuel cells then summarizes the existing hybrid power circuit topology categorizes the existing technical solutions and finally looks forward to the future for different scenarios of hydrogen fuel cell hybrid power systems. This paper provides reference and guidance for the future development of renewable hydrogen energy and hydrogen fuel cell hybrid electric vehicles.
Concepts for Hydrogen Internal Combustion Engines and Their Implications on the Exhaust Gas Aftertreatment System
Dec 2021
Publication
Hydrogen as carbon-free fuel is a very promising candidate for climate-neutral internal combustion engine operation. In comparison to other renewable fuels hydrogen does obviously not produce CO2 emissions. In this work two concepts of hydrogen internal combustion engines (H2 -ICEs) are investigated experimentally. One approach is the modification of a state-of-the-art gasoline passenger car engine using hydrogen direct injection. It targets gasoline-like specific power output by mixture enrichment down to stoichiometric operation. Another approach is to use a heavy-duty diesel engine equipped with spark ignition and hydrogen port fuel injection. Here a diesel-like indicated efficiency is targeted through constant lean-burn operation. The measurement results show that both approaches are applicable. For the gasoline engine-based concept stoichio-metric operation requires a three-way catalyst or a three-way NOX storage catalyst as the primary exhaust gas aftertreatment system. For the diesel engine-based concept state-of-the-art selective catalytic reduction (SCR) catalysts can be used to reduce the NOx emissions provided the engine calibration ensures sufficient exhaust gas temperature levels. In conclusion while H2 -ICEs present new challenges for the development of the exhaust gas aftertreatment systems they are capable to realize zero-impact tailpipe emission operation.
Utilization of Food Waste for Hydrogen-based Power Generation: Evidence from Four Cities in Ghana
Mar 2023
Publication
Hydrogen gas will be an essential energy carrier for global energy systems in the future. However non-renewable sources account for 96% of the production. Food wastes have high hydrogen generation potential which can positively influence global production and reduce greenhouse gas (GHG) emissions. The study evaluates the potential of food waste hydrogen-based power generation through biogas steam reforming and its environmental and economic impact in major Ghanaian cities. The results highlight that the annual hydrogen generation in Kumasi had the highest share of 40.73 kt followed by Accra with 31.62 kt while the least potential was in Tamale (3.41 kt). About 2073.38 kt was generated in all the major cities. Hydrogen output is predicted to increase from 54.61 kt in 2007 to 119.80 kt by 2030. Kumasi produced 977.54 kt of hydrogen throughout the 24-year period followed by Accra with 759.76 kt Secondi-Takoradi with 255.23 kt and Tamale with 81.85 kt. According to the current study Kumasi had the largest percentage contribution of hydrogen (47.15%) followed by Accra (36.60%) Secondi-Takoradi (12.31%) and Tamale (3.95%). The annual power generation potential in Kumasi and Accra was 73.24 GWh and 56.85 GWh. Kumasi and Accra could offset 8.19% and 6.36% of Ghana's electricity consumption. The total electricity potential of 3728.35 GWh could displace 17.37% of Ghana's power consumption. This electricity generated had a fossil diesel displacement capacity of 1125.90 ML and could reduce GHG emissions by 3060.20 kt CO2 eq. Based on the findings the total GHG savings could offset 8.13% of Ghana's carbon emissions. The cost of power generation from hydrogen is $ 0.074/kWh with an annual positive net present value of $ 658.80 million and a benefit-to-cost ratio of 3.43. The study lays the foundation and opens policy windows for sustainable hydrogen power generation in Ghana and other African countries.
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