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The Race Between Hydrogen and Heat Pumps for Space and Water Heating: A Model-based Scenario Analysis
Nov 2023
Publication
This paper analyses different levels and means of the electrification of space and hot water heating using an explorative modelling approach. The analysis provides guidance to the ongoing discussion on favourable pathways for heating buildings and the role of secondary energy carriers such as hydrogen or synthetic fuels. In total 12 different scenarios were modelled with decarbonisation pathways until 2050 which cover all 27 member states of the European Union. Two highly detailed optimisation models were combined to cover the building stock and the upstream energy supply sector. The analysis shows that decarbonisation pathways for space and water heating based on large shares of heat pumps have at least 11% lower system costs in 2050 than pathways with large shares of hydrogen or synthetic fuels. This translates into system cost savings of around €70 bn. Heat pumps are cost-efficient in decentralised systems and in centralised district heating systems. Hence heat pumps should be the favoured option to achieve a cost-optimal solution for heating buildings. Accordingly the paper makes a novel and significant contribution to understanding suitable and cost-efficient decarbonisation pathways for space and hot water heating via electrification. The results of the paper can provide robust guidance for policymakers.
Design of an Electric Vehicle Charging System Consisting of PV and Fuel Cell for Historical and Tourist Regions
Jun 2024
Publication
One of the most important problems in the widespread use of electric vehicles is the lack of charging infrastructure. Especially in tourist areas where historical buildings are located the installation of a power grid for the installation of electric vehicle charging stations or generating electrical energy by installing renewable energy production systems such as large-sized PV (photovoltaic) and wind turbines poses a problem because it causes the deterioration of the historical texture. Considering the need for renewable energy sources in the transportation sector our aim in this study is to model an electric vehicle charging station using PVPS (photovoltaic power system) and FC (fuel cell) power systems by using irradiation and temperature data from historical regions. This designed charging station model performs electric vehicle charging meeting the energy demand of a house and hydrogen production by feeding the electrolyzer with the surplus energy from producing electrical energy with the PVPS during the daytime. At night when there is no solar radiation electric vehicle charging and residential energy demand are met with an FC power system. One of the most important advantages of this system is the use of hydrogen storage instead of a battery system for energy storage and the conversion of hydrogen into electrical energy with an FC. Unlike other studies in our study fossil energy sources such as diesel generators are not included for the stable operation of the system. The system in this study may need hydrogen refueling in unfavorable climatic conditions and the energy storage capacity is limited by the hydrogen fuel tank capacity.
Optimal Expansion of a Multi-domain Virtual Power Plant for Green Hydrogen Production to Decarbonise Seaborne Passenger Transportation
Nov 2023
Publication
Many industrialised nations recently concentrated their focus on hydrogen as a viable option for the decarbonisation of fossil-intensive sectors including maritime transportation. A sustainable alternative to the conventional production of hydrogen based on fossil hydrocarbons is water electrolysis powered by renewable energy sources. This paper presents a detailed techno-economic optimisation model for sizing an electrolyser and a hydrogen storage embedded in a multi-domain virtual power plant to produce green hydrogen for seaborne passenger transportation. We base our numerical analysis on three years of historical data from a renewable-dominated 60/10 kV substation on the Danish island of Bornholm and on data for ferries to the mainland of Sweden. Our analysis shows that an electrolyser system serves as a valuable flexibility asset on the electrical demand side while supporting the thermal management of the district heating system and contributing to meeting the ferries hydrogen demand. With a sized electrolyser of 9.63 MW and a hydrogen storage of 1.45 t the hydrogen assets are able to take up a large share of the local excess electricity generation. The waste heat of the electrolyser delivers a significant share of 21.4% of the annual district heating demand. Moreover the substation can supply 26% of the hydrogen demand of the ferries from local resources. We further examine the sensitivity of the asset sizing towards investment costs electrolyser efficiency and hydrogen market prices.
Energy Efficiency Analysis of a Fuel Cell Bus Model Using Real Scenarios Generated by Data Collection
Feb 2024
Publication
Modernizing public transportation is crucial given the ongoing call for sustainable mobility. Growing concerns about climate change and the increasingly stringent emissions standards have compelled public transport operators to embrace alternative propulsion vehicles on a broader scale. For the past years the Battery Electric Buses (BEBs) have been the vehicle of choice for public transportation. However an emerging contender in this sector is the Fuel Cell Electric Bus (FCEB). This paper aims to evaluate the way one such vehicle would perform in terms of energy efficiency while being exploited in an urban scenario generated from collected data.
The Heat Transfer Potential of Compressor Vanes on a Hydrogen Fueled Turbofan Engine
Sep 2023
Publication
Hydrogen is a promising fuel for future aviation due to its CO2-free combustion. In addition its excellent cooling properties as it is heated from cryogenic conditions to the appropriate combustion temperatures provides a multitude of opportunities. This paper investigates the heat transfer potential of stator surfaces in a modern high-speed low-pressure compressor by incorporating cooling channels within the stator vane surfaces where hydrogen is allowed to flow and cool the engine core air. Computational Fluid Dynamics simulations were carried out to assess the aerothermal performance of this cooled compressor and were compared to heat transfer correlations. A core air temperature drop of 9.5 K was observed for this cooling channel design while being relatively insensitive to the thermal conductivity of the vane and cooling channel wall thickness. The thermal resistance was dominated by the air-side convective heat transfer and more surface area on the air-side would therefore be required in order to increase overall heat flow. While good agreement with established heat transfer correlations was found for both turbulent and transitional flow the correlation for the transitional case yielded decent accuracy only as long as the flow remains attached and while transition was dominated by the bypass mode. A system level analysis indicated a limited but favorable impact at engine performance level amounting to a specific fuel consumption improvement of up to 0.8% in cruise and an estimated reduction of 3.6% in cruise NOx. The results clearly show that although it is possible to achieve high heat transfer rate per unit area in compressor vanes the impact on cycle performance is constrained by the limited available wetted area in the low-pressure compressor.
Case Study: Quantitative Risk Assessment of Hydrogen Blended Natural Gas for an Existing Distribution Network and End-use Equipment in Fort Saskatchewan, Alberta
Sep 2023
Publication
In a first-of-its-kind project for Alberta ATCO Gas and Pipelines Ltd. (ATCO) began delivering a 5% blend of hydrogen (H2) in natural gas into a subsection of the existing Fort Saskatchewan natural gas distribution system (approximately 2100 customers). The project was commissioned in October 2022 with the intention of increasing the blend to 20% H₂ in 2023. As part of project due diligence ATCO in partnership with DNV undertook Quantitative Risk Assessments (QRAs) to understand any risks associated with the introduction of blended gas into its existing distribution system and to its customers. This paper describes key findings from the QRAs through the comparison of risks associated with H2 blended natural gas at concentrations of 5% and 20% H₂ and the current natural gas configuration. The impact of operating pressure and hydrogen blend composition formed a sensitivity study completed as part of this work. To provide context and to help interpret the results an individual risk (IR) level of 1 × 10-6 per year was utilised as a reference threshold for the limit of the ‘broadly acceptable’ risk level and juxtaposed against comparable risk scenarios. Although adding hydrogen increases the IR of ignited releases from mains services meters regulators and end user appliances the ignited release IR was always well below the broadly acceptable reference criterion for all operating pressures and blend cases considered as part of the project. The IR associated with carbon monoxide poisoning dominates the overall IR and the results demonstrate that the reduction in carbon monoxide poisoning associated with the introduction of H₂ blended natural gas negates any incremental risk associated with ignited releases due to H₂ blended gas. The paper also explains how the results of the QRA were incorporated into Engineering Assessments as per the requirements of CSA Z662:19 [1] to justify the conversion of existing natural gas infrastructure to H₂ blended gas infrastructure.
Internal Combustion Engines and Carbon-Neutral Fuels: A Perspective on Emission Neutrality in the European Union
Mar 2024
Publication
Nowadays there is an intense debate in the European Union (EU) regarding the limits to achieve the European Green Deal to make Europe the first climate-neutral continent in the world. In this context there are also different opinions about the role that thermal engines should play. Furhermore there is no clear proposal regarding the possibilities of the use of green hydrogen in the transport decarbonization process even though it should be a key element. Thus there are still no precise guidelines regarding the role of green hydrogen with it being exclusively used as a raw material to produce E-fuels. This review aims to evaluate the possibilities of applying the different alternative technologies available to successfully complete the process already underway to achieve Climate Neutrality by about 2050 depending on the maturity of the technologies currently available and those anticipated to be available in the coming decades.
A Comprehensive Review on Condition Monitoring and Fault Diagnosis in Fuel Cell Systems: Challenges and Issues
Jan 2024
Publication
The complexity of Fuel Cell (FC) systems demands a profound and sustained understanding of the various phenomena occurring inside of it. Thus far FCs especially Proton Exchange Membrane Fuel Cells (PEMFCs) have been recognized as being among the most promising technologies for reducing Green House Gas (GHG) emissions because they can convert the chemical energy bonded to hydrogen and oxygen into electricity and heat. However their efficiency remains limited. To enhance their efficiency two distinct factors are suggested. First the quality of materials plays a significant role in the development of more robust and efficient FCs. Second the ability to identify mitigate and reduce the occurrence of faults through the use of robust control algorithms is crucial. Therefore more focused on the second point this paper compiles distinguishes and analyzes several publications from the past 25 years related to faults and their diagnostic techniques in FCs. Furthermore the paper presents various schemes outlining different symptoms their causes and corresponding fault algorithms.
Mitigating Risks in Hydrogen-powered Transportation: A Comprehensive Risk Assessment for Hydrogen Refuelling Stations, Vehicles, and Garages
Oct 2024
Publication
Hydrogen is increasingly seen as a viable alternative to fossil fuels in transportation crucial to achieving net-zero energy goals. However the rapid expansion of hydrogen-powered transportation is outpacing safety standards posing significant risks due to limited operational experience involvement of new actors and lack of targeted guidelines. This study addresses the urgent need for a tailored comprehensive risk assessment framework. Using Structured What-If (SWIFT) and bowtie barrier analysis the research evaluates a hypothetical pilot project focusing on hydrogen refuelling stations vehicles and garages. The study identifies critical hazards and assesses the adequacy of current risk mitigation measures. Key findings reveal gaps in safety practices leading to 41 actionable steps and 5 key activities to help new actors manage hydrogen risks effectively. By introducing novel safety guidelines this research contributes to the development of safe hydrogen use and advances the understanding of hydrogen risks ensuring its sustainable integration into transportation systems.
Current and Future Role of Natural Gas Supply Chains in the Transition to a Low-Carbon Hydrogen Economy: A Comprehensive Review on Integrated Natural Gas Supply Chain Optimisation Models
Nov 2023
Publication
Natural gas is the most growing fossil fuel due to its environmental advantages. For the economical transportation of natural gas to distant markets physical (i.e. liquefaction and compression) or chemical (i.e. direct and indirect) monetisation options must be considered to reduce volume and meet the demand of different markets. Planning natural gas supply chains is a complex problem in today’s turbulent markets especially considering the uncertainties associated with final market demand and competition with emerging renewable and hydrogen energies. This review study evaluates the latest research on mathematical programming (i.e. MILP and MINLP) as a decisionmaking tool for designing and planning natural gas supply chains under different planning horizons. The first part of this study assesses the status of existing natural gas infrastructures by addressing readily available natural monetisation options quantitative tools for selecting monetisation options and single-state and multistate natural gas supply chain optimisation models. The second part investigates hydrogen as a potential energy carrier for integration with natural gas supply chains carbon capture utilisation and storage technologies. This integration is foreseen to decarbonise systems diversify the product portfolio and fill the gap between current supply chains and the future market need of cleaner energy commodities. Since natural gas markets are turbulent and hydrogen energy has the potential to replace fossil fuels in the future addressing stochastic conditions and demand uncertainty is vital to hedge against risks through designing a responsive supply chain in the project’s early design stages. Hence hydrogen supply chain optimisation studies and the latest works on hydrogen–natural gas supply chain optimisation were reviewed under deterministic and stochastic conditions. Only quantitative mathematical models for supply chain optimisation including linear and nonlinear programming models were considered in this study to evaluate the effectiveness of each proposed approach.
Advancing Renewable Energy: Strategic Modeling and Optimization of Flywheel and Hydrogen-based Energy System
Sep 2024
Publication
This study introduces a hybrid energy storage system that combines advanced flywheel technology with hydrogen fuel cells and electrolyzers to address the variability inherent in renewable energy sources like solar and wind. Flywheels provide quick energy dispatch to meet peak demand while hydrogen fuel cells offer sustained power over extended periods. The research explores the strategic integration of these technologies within a hybrid photovoltaic (PV)-flywheel‑hydrogen framework aiming to stabilize the power supply. To evaluate the impact of flywheel integration on system sizing and load fluctuations simulations were conducted both before and after the flywheel integration. The inclusion of the flywheel resulted in a more balanced energy production and consumption profile across different seasons notably reducing the required fuel cell capacity from 100 kW to 30 kW. Additionally the integration significantly enhanced system stability enabling the fuel cell and electrolyzer to operate at consistent power during load fluctuations. The system achieved efficiencies of 71.42 % for the PEM electrolyzer and 62.14 % for the PEM fuel cell. However the introduction of the flywheel requires a higher capacity of PV modules and a larger electrolyzer. The overall flywheel's efficiency was impacted by parasitic energy losses resulting in an overall efficiency of 46.41 %. The minimum efficiency observed across various scenarios of the model studied was 3.14 % highlighting the importance of considering these losses in the overall system design. Despite these challenges the hybrid model demonstrated a substantial improvement in the reliability and stability of renewable energy systems effectively bridging short-term and long-term energy storage solutions.
The Influence of the Changes in Natural Gas Supplies to Poland on the Amount of Hydrogen Produced in the SMR Reactor
Mar 2024
Publication
Thanks to investments in diversifying the supply of natural gas Poland did not encounter any gas supply issues in 2022 when gas imports from Russia were ceased due to the Russian Federation’s armed intervention in Ukraine. Over the past few years the supply of gas from routes other than the eastern route has substantially grown particularly the supplies of liquefied natural gas (LNG) via the LNG terminal in Swinouj´scie. The growing proportion of LNG in Poland’s gas supply ´ leads to a rise in ethane levels in natural gas as verified by the review of data taken at a specific location within the gas system over the years 2015 2020 and 2022. Using measurements of natural gas composition the effectiveness of the steam hydrocarbon reforming process was simulated in the Gibbs reactor via Aspen HYSYS. The simulations confirmed that as the concentration of ethane in the natural gas increased the amount of hydrogen produced and the heat required for reactions in the reformer also increased. This article aims to analyze the influence of the changes in natural gas quality in the Polish transmission network caused by changes in supply structures on the mass and heat balance of the theoretical steam reforming reactor. Nowadays the chemical composition of natural gas may be significantly different from that assumed years ago at the plant’s design stage. The consequence of such a situation may be difficulties in operating especially when controlling the quantity of incoming natural gas to the reactor based on volumetric flow without considering changes in chemical composition.
A SWOT Analysis of the Green Hydrogen Market
Jun 2024
Publication
Since the Industrial Revolution humanity has heavily depended on fossil fuels. Recognizing the negative environmental impacts of the unmoderated consumption of fossil fuels including global warming and consequent climate change new plans and initiatives have been established to implement renewable and sustainable energy sources worldwide. This has led to a rapid increase in the installed solar and wind energy capacity. However considering the fluctuating nature of these renewable energy sources green hydrogen has been proposed as a suitable energy carrier to improve the efficiency of energy production and storage. Thus green hydrogen produced by water electrolysis using renewable electricity is a promising solution for the future energy market. Moreover it has the potential to be used for the decarbonization of the heavy industry and transportation sectors. Research and development (R&D) on green hydrogen has grown considerably over the past few decades aiming to maximize production and expand its market share. The present work uses a SWOT (strengths weaknesses opportunities and threats) analysis to evaluate the current status of the green hydrogen market. The external and internal factors that affect its market position are assessed. The results show that green hydrogen is on the right track to becoming a competitive alternative to fossil fuels soon. Supported by environmental benefits government incentives and carbon taxes roadmaps to position green hydrogen on the energy map have been outlined. Nevertheless increased investments are required for further R&D as costs must be reduced and policies enforced. These measures will gradually decrease global dependency on fossil fuels and ensure that roadmaps are followed through.
Research & Innovation for Climate Neutrality 2050: Challenges, Opportunities & the Path Forward
Jan 2024
Publication
Transforming Europe into a climate neutral economy and society by 2050 requires extraordinary efforts and the mobilisation of all sectors and economic actors coupled with all the creative and brain power one can imagine. Each sector has to fundamentally rethink the way it operates to ensure it can be transformed towards this new net-zero paradigm without jeopardising other environmental and societal objectives both within the EU and globally. Given the scale of the transformation ahead our ability to meet climate neutrality targets directly depends on our ability to innovate. In this context Research & Innovation programmes have a key role to play and it is crucial to ensure they are fit for purpose and well equipped to support the next wave of breakthrough innovations that will be required to achieve climate neutrality in the EU and globally by 2050. The objective of this study is to contribute to these strategic planning discussions by not only identifying high-risk and high-impact climate mitigation solutions but most importantly look beyond individual solutions and consider how systemic interactions of climate change mitigation approaches can be integrated in the development of R&I agendas.
Coupling Green Hydrogen Production to Community Benefits: A Pathway to Social Acceptance?
Feb 2024
Publication
Hydrogen energy technologies are forecasted to play a critical supporting role in global decarbonisation efforts as reflected by the growth of national hydrogen energy strategies in recent years. Notably the UK government published its Hydrogen Strategy in August 2021 to support decarbonisation targets and energy security ambitions. While establishing techno-economic feasibility for hydrogen energy systems is a prerequisite of the prospective transition social acceptability is also needed to support visions for the ‘hydrogen economy’. However to date societal factors are yet to be embedded into policy prescriptions. Securing social acceptance is especially critical in the context of ‘hydrogen homes’ which entails replacing natural gas boilers and hobs with low-carbon hydrogen appliances. Reflecting the nascency of hydrogen heating and cooking technologies the dynamics of social acceptance are yet to be explored in a comprehensive way. Similarly public perceptions of the hydrogen economy and emerging national strategies remain poorly understood. Given the paucity of conceptual and empirical insights this study develops an integrated acceptance framework and tests its predictive power using partial least squares structural equation modelling. Results highlight the importance of risk perceptions trust dynamics and emotions in shaping consumer perceptions. Foremost prospects for deploying hydrogen homes at scale may rest with coupling renewable-based hydrogen production to local environmental and socio-economic benefits. Policy prescriptions should embed societal factors into the technological pursuit of large-scale sustainable energy solutions to support socially acceptable transition pathways.
Path Analysis of Using Hydrogen Energy to Reduce Greenhouse Gas Emissions in Global Aviation
Jul 2024
Publication
The rapid growth of global aviation emissions has significantly impacted the environment leading to an urgent need to use carbon reduction methods. This paper analyzes global aviation’s carbon dioxide (CO2) N2O and CH4 emission changes under different hydrogen energy application paths. The global warming potential over a 100-year period (GWP100) method is used to convert the emissions of N2O and CH4 into CO2-equivalent. Here we report the results: if the global aviation industry begins using hydrogen turbine engines by 2040 it could reduce cumulative CO2-equivalent emissions by 2.217E+10 tons by 2080 which is 2.12% higher than starting hydrogen fuel cell engines in 2045. However adopting hydrogen fuel cell engines 10 years earlier shows greater reduction capabilities than hydrogen turbine engines achieving an accumulated reduction of 3.006E+10 tons of CO2-equivalent emissions. Therefore the timing of adoption notably affects hydrogen fuel cell engines more than hydrogen turbine engines. Delaying adoption makes hydrogen fuel cell engines’ performance lag hydrogen turbine engines.
Numerical Analysis of the Hydrogen-air Mixture Formation Process in a Direct-injection Engine for Off-road Applications
Jun 2024
Publication
Among the different hydrogen premixed combustion concepts direct injection (DI) is one of the most promising for internal combustion engine (ICE) applications. However to fully exploit the benefits of this solution the optimization of the mixture preparation process is a crucial factor. In the present work a study of the hydrogenair mixture formation process in a DI H2-ICE for off-road applications was performed through 3D-CFD simulations. First a sensitivity analysis on the injection timing was carried out to select the optimal injection operating window capable of maximizing mixture homogeneity without a significant volumetric efficiency reduction. Then different spray injector guiding caps were tested to assess their effect on in-cylinder dynamics and mixture characteristics consequently. Finally the impact of swirl intensity on hydrogen distribution has been assessed. The optimization of the combustion chamber geometry has allowed the achievement of significant improvements in terms of mixture homogeneity.
Nuclear Enabled Hydrogen CO-generation: Safety and Regulatory Insight
Sep 2023
Publication
National Nuclear Laboratory (NNL) is aiming to demonstrate through a research and development programme that nuclear enabled hydrogen can be used to support future clean energy systems. Demonstrating the safe operation of hydrogen facilities co-generating with a nuclear reactor will be key to enabling the deployment and success of nuclear enabled hydrogen technologies in the future. During the deployment continuity of supply will be paramount and possibly requires inter-seasonal storage. Co-generation is a means of using a source of energy in this case a nuclear reactor to efficiently produce power and thermal energy. Since a great deal of the heat energy is lost to the environment in a power plant making use of wasted energy for other useful output like the production of hydrogen and direct heating would be advantageous to plant economics and energy system flexibility. The civil nuclear industry is regulated around the world. This approach ensures that all the activities related to the production of power from nuclear and the hazards associated with ionising radiation are controlled in a manner which protects workers members of the public property and the environment. Nuclear safety assessments follow a rigorous process and are required as part of the Nuclear Site Licence. A fundamental requirement which is cited in the UK legislation is that the risks associated with all activities at the licensed site be reduced to As Low As Reasonably Practicable (ALARP). The principle places a requirement on duty holders to implement measures to reduce risk where doing so is considered reasonable and proportionate. The inclusion of risks for hazardous materials associated with the hydrogen production facilities need to be considered and this requires harmonisation of two different safety and regulatory governance regimes which have not previously interacted in this way. The safety demonstration for nuclear facilities is provided through the Safety Case.
Safe Pipelines for Hydrogen Transport
Jun 2024
Publication
The hydrogen compatibility of two X65 pipeline steels for transport of hydrogen gas is investigated through microstructural characterization hydrogen permeation measurements and fracture mechanical testing. The investigated materials are a quenched and tempered pipeline steel with a fine-grained homogeneously distributed ferrite-bainite microstructure and hot rolled pipeline steel with a ferrite-pearlite banded microstructure. All tests are performed both under electrochemical and gaseous hydrogen charging conditions. A correlation between electrochemical hydrogen charging and gaseous charging is determined. The results point to inherent differences in the interaction between hydrogen and the two material microstructures. Further research is needed to unveil the influence of material microstructure on hydrogen embrittlement.
An Overview of Application-orientated Multifunctional Large-scale Stationary Battery and Hydrogen Hybrid Energy Storage System
Dec 2023
Publication
The imperative to address traditional energy crises and environmental concerns has accelerated the need for energy structure transformation. However the variable nature of renewable energy poses challenges in meeting complex practical energy requirements. To address this issue the construction of a multifunctional large-scale stationary energy storage system is considered an effective solution. This paper critically examines the battery and hydrogen hybrid energy storage systems. Both technologies face limitations hindering them from fully meeting future energy storage needs such as large storage capacity in limited space frequent storage with rapid response and continuous storage without loss. Batteries with their rapid response (90%) excel in frequent short-duration energy storage. However limitations such as a selfdischarge rate (>1%) and capacity loss (~20%) restrict their use for long-duration energy storage. Hydrogen as a potential energy carrier is suitable for large-scale long-duration energy storage due to its high energy density steady state and low loss. Nevertheless it is less efficient for frequent energy storage due to its low storage efficiency (~50%). Ongoing research suggests that a battery and hydrogen hybrid energy storage system could combine the strengths of both technologies to meet the growing demand for large-scale long-duration energy storage. To assess their applied potentials this paper provides a detailed analysis of the research status of both energy storage technologies using proposed key performance indices. Additionally application-oriented future directions and challenges of the battery and hydrogen hybrid energy storage system are outlined from multiple perspectives offering guidance for the development of advanced energy storage systems.
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