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Powering Europe with North Sea Offshore Wind: The Impact of Hydrogen Investments on Grid Infrastructure and Power Prices
Oct 2022
Publication
Hydrogen will be a central cross-sectoral energy carrier in the decarbonization of the European energy system. This paper investigates how a large-scale deployment of green hydrogen production affects the investments in transmission and generation towards 2060 analyzes the North Sea area with the main offshore wind projects and assesses the development of an offshore energy hub. Results indicate that the hydrogen deployment has a tremendous impact on the grid development in Europe and in the North Sea. Findings indicate that total power generation capacity increases around 50%. The offshore energy hub acts mainly as a power transmission asset leads to a reduction in total generation capacity and is central to unlock the offshore wind potential in the North Sea. The effect of hydrogen deployment on power prices is multifaceted. In regions where power prices have typically been lower than elsewhere in Europe it is observed that hydrogen increases the power price considerably. However as hydrogen flexibility relieves stress in high-demand periods for the grid power prices decrease in average for some countries. This suggests that while the deployment of green hydrogen will lead to a significant increase in power demand power prices will not necessarily experience a large increase.
A Review of Hydrogen/rock/brine Interaction: Implications for Hydrogen Geo-storage
Dec 2022
Publication
Hydrogen (H2) is currently considered a clean fuel to decrease anthropogenic greenhouse gas emissions and will play a vital role in climate change mitigation. Nevertheless one of the primary challenges of achieving a complete H2 economy is the large-scale storage of H2 which is unsafe on the surface because H2 is highly compressible volatile and flammable. Hydrogen storage in geological formations could be a potential solution to this problem because of the abundance of such formations and their high storage capacities. Wettability plays a critical role in the displacement of formation water and determines the containment safety storage capacity and amount of trapped H2 (or recovery factor). However no comprehensive review article has been published explaining H2 wettability in geological conditions. Therefore this review focuses on the influence of various parameters such as salinity temperature pressure surface roughness and formation type on wettability and consequently H2 storage. Significant gaps exist in the literature on understanding the effect of organic material on H2 storage capacity. Thus this review summarizes recent advances in rock/H2/brine systems containing organic material in various geological reservoirs. The paper also presents influential parameters affecting H2 storage capacity and containment safety including liquid–gas interfacial tension rock–fluid interfacial tension and adsorption. The paper aims to provide the scientific community with an expert opinion to understand the challenges of H2 storage and identify storage solutions. In addition the essential differences between underground H2 storage (UHS) natural gas storage and carbon dioxide geological storage are discussed and the direction of future research is presented. Therefore this review promotes thorough knowledge of UHS provides guidance on operating large-scale UHS projects encourages climate engineers to focus more on UHS research and provides an overview of advanced technology. This review also inspires researchers in the field of climate change to give more credit to UHS studies.
Spatially-resolved Analysis of the Challenges and Opportunities of Power-to-Gas (PtG) in Baden-Württemberg until 2040
Mar 2017
Publication
The increasing penetration of renewable energies will make new storage technologies indispensable in the future. Power-to-Gas (PtG) is one long-term storage technology that exploits the existing gas infrastructure. However this technology faces technical economic environmental challenges and questions. This contribution presents the final results of a large research project which attempted to address and provide answers to some of these questions for Baden-Württemberg (south west Germany). Three energy scenarios out to 2040 were defined one oriented towards the Integrated Energy and Climate Protection Concept of the Federal State Government and two alternatives. Timely-resolved load profiles for gas and electricity for 2015 2020 2030 and 2040 have been generated at the level of individual municipalities. The profiles include residential and industrial electrical load gas required for heating (conventional and current-controlled CHP) as well as gas and electricity demand for mobility. The installation of rooftop PV-plants and wind power plants is projected based on bottom up cost-potential analyses which account for some social acceptance barriers. Residential load profiles are derived for each municipality. In times with negative residual load the PtG technology could be used to convert electricity into hydrogen or methane. The detailed analysis of four structurally-different model regions delivered quite different results. While in large cities no negative residual load is likely due to the continuously high demand and strong networks rural areas with high potentials for renewables could encounter several thousand hours of negative residual load. A cost-effective operation of PtG would only be possible under favorable conditions including high full load hours a strong reduction in costs and a technical improvement of efficiency. Whilst these conditions are not expected to appear in the short to mid-term but may occur in the long term in energy systems with very high shares of renewable energy sources
Stoichiometric Equilibrium Model based Assessment of Hydrogen Generation through Biomass Gasification
Sep 2016
Publication
Hydrogen produced from renewable energy sources is clean and sustainable. Biomass gasification has a significant role in the context of hydrogen generation from biomass. Assessment of the performance of biomass gasification process regarding the product gas yield and composition can be performed using mathematical models. Among the different mathematical models thermodynamic equilibrium models are simple and useful tools for the first estimate and preliminary comparison and assessment of gasification process. A stoichiometric thermodynamic equilibrium model is developed here and its performance is validated for steam gasification and air-steam gasification. The model is then used to assess the feasibility of different biomass feedstock for gasification based on hydrogen yield and lower heating value.
Alternative and Innovative Solid Oxide Electrolysis Cell Materials: A Short Review
Jun 2021
Publication
Solid oxide electrolysis cell is the leading technology for production of green hydrogen by high temperature electrolysis. However optimization of existing reference materials constituting the cell and development of innovative materials remain critical for solid oxide electrolysis cell. In particular they are key to reach performance and durability targets compatible with a commercialization for the three main markets identified as follows: large-scale H2 production Power-to-X and Power-to-Power. This short review summarizes the latest progress in research and development of alternative and innovative materials for solid oxide electrolysis cells with a main focus on cathode-supported cell materials. A brief description of the layers constituting the solid oxide electrolysis cell is provided with the associated current state-of-the-art materials. A further emphasis on the most promising alternative and innovative materials for each layer follows based on the major aspects from an industrial perspective to reach a competitive hydrogen production cost for the main targeted markets: performance durability scaling up/manufacturing ability and operational flexibility.
Hybrid PEM Fuel Cell Power Plants Fuelled by Hydrogen for Improving Sustainability in Shipping: State of the Art and Review on Active Projects
Feb 2023
Publication
The interest in hybrid polymer electrolyte membrane fuel cells (PEMFC) fuelled by hydrogen in shipping has seen an unprecedented growth in the last years as it could allow zero-emission navigation. However technical safety and regulatory barriers in PEMFC ship design and operation are hampering the use of such systems on a large scale. While several studies analyse these aspects a comprehensive and up-to-date overview on hydrogen PEMFCs for shipping is missing. Starting from the survey of past/ongoing projects on FCs in shipping this paper presents an extensive review on maritime hydrogen PEMFCs outlining the state of the art and future trends for hydrogen storage and bunkering powertrain and regulations. In addition to the need for a clear regulatory framework future studies should investigate the development of an efficient fuel supply chain and bunkering facilities ashore. As for the onboard power system health-conscious energy management low-temperature heat recovery and advancements in fuel processing have emerged as hot research topics.
Economic Feasibility of Green Hydrogen in Providing Flexibility to Medium-voltage Distribution Grids in the Presence of Local-heat Systems
Nov 2022
Publication
The recent strong increase in the penetration of renewable energy sources (RESs) in medium-voltage distribution grids (MVDNs) has raised the need for congestion management in such grids as they were not designed for this new condition. This paper examines to what extent producing green hydrogen through electrolyzers can profitably contribute to congestion alleviation in MVDNs in the presence of high amounts of RES as well as flexible consumers of electricity and a local heat system. To address this issue an incentive-based method for improving flexibility in MVDNs is used which is based on a single-leader–multiple-followers game formulated by bi-level mathematical programming. At the upper level the distribution system operator who is the leader of this game determines dynamic prices as incentives at each node based on the levels of generation and load. Next at the lower level providers of flexibility including producers using electrolyzers price-responsive power consumers heat consumers as well as heat producers respond to these incentives by reshaping their output and consumption patterns. The model is applied to a region in the North of The Netherlands. The obtained results demonstrate that converting power to hydrogen can be an economically efficient way to reduce congestion in MVDNs when there is a high amount of RES. However the economic value of electrolyzers as providers of flexibility to MVDNs decreases when more other options for flexibility provision exist.
Solid Air Hydrogen Liquefaction, the Missing Link of the Hydrogen Economy
Mar 2023
Publication
The most challenging aspect of developing a green hydrogen economy is long-distance oceanic transportation. Hydrogen liquefaction is a transportation alternative. However the cost and energy consumption for liquefaction is currently prohibitively high creating a major barrier to hydrogen supply chains. This paper proposes using solid nitrogen or oxygen as a medium for recycling cold energy across the hydrogen liquefaction supply chain. When a liquid hydrogen (LH2) carrier reaches its destination the regasification process of the hydrogen produces solid nitrogen or oxygen. The solid nitrogen or oxygen is then transported in the LH2 carrier back to the hydrogen liquefaction facility and used to reduce the energy consumption cooling gaseous hydrogen. As a result the energy required to liquefy hydrogen can be reduced by 25.4% using N2 and 27.3% using O2. Solid air hydrogen liquefaction (SAHL) can be the missing link for implementing a global hydrogen economy.
Assessment of Hydrogen Delivery Options: Feasibility of Transport of Green Hydrogen within Europe
Oct 2022
Publication
The RePowerEU plan [1] and the European Hydrogen Strategy [2] recognise the important role that the transport of hydrogen will play in enabling the penetration of renewable hydrogen in Europe. To implement the European Hydrogen Strategy it is important to understand whether the transport of hydrogen is cost effective or whether hydrogen should be produced where it is used. If transporting hydrogen makes sense a second open question is how long the transport route should be for the cost of the hydrogen to still be competitive with locally produced hydrogen. JRC has performed a comprehensive study regarding the transport of hydrogen. To investigate which renewable hydrogen delivery pathways are favourable in terms of energy demand and costs JRC has developed a database and an analytical tool to assess each step of the pathways and used it to assess two case studies. The study reveals that there is no single optimal hydrogen delivery solution across every transport scenario. The most cost effective way to deliver renewable hydrogen depends on distance amount final use and whether there is infrastructure already available. For distances compatible with the European territory compressed and liquefied hydrogen solutions and especially compressed hydrogen pipelines offer lower costs than chemical carriers do. The repurposing of existing natural gas pipelines for hydrogen use is expected to significantly lower the delivery cost making the pipeline option even more competitive in the future. By contrast chemical carriers become more competitive the longer the delivery distance (due to their lower transport costs) and open up import options from suppliers located for example in Chile or Australia.
Review of the Effects of Fossil Fuels and the Need for a Hydrogen Fuel Cell Policy in Malaysia
Feb 2023
Publication
The world has relied on fossil fuel energy for a long time producing many adverse effects. Long-term fossil fuel dependency has increased carbon emissions and accelerated climate change. In addition fossil fuels are also depleting and will soon be very costly. Moreover the expensive national electricity grid has yet to reach rural areas and will be cut off in inundation areas. As such alternative and carbon-free hydrogen fuel cell energy is highly recommended as it solves these problems. The reviews find that (i) compared to renewable energy such as solar biomass and hydropower a fuel cell does not require expensive transmission through an energy grid and is carbon-free and hence it is a faster agent to decelerate climate change; (ii) fuel cell technologies have reached an optimum level due to the high-efficiency production of energy and they are environmentally friendly; (iii) the absence of a policy on hydrogen fuel cells will hinder investment from private companies as they are not adequately regulated. It is thus recommended that countries embarking on hydrogen fuel cell development have a specific policy in place to allow the government to fund and regulate hydrogen fuel cells in the energy generation mix. This is essential as it provides the basis for alternative energy governance development and management of a country.
The Effects of Fuel Type and Cathode Off-gas Recirculation on Combined Heat and Power Generation of Marine SOFC Systems
Dec 2022
Publication
An increasing demand in the marine industry to reduce emissions led to investigations into more efficient power conversion using fuels with sustainable production pathways. Solid Oxide Fuel Cells (SOFCs) are under consideration for long-range shipping because of its high efficiency low pollutant emissions and fuel flexibility. SOFC systems also have great potential to cater for the heat demand in ships but the heat integration is not often considered when assessing its feasibility. This study evaluates the electrical and heat efficiency of a 100 kW SOFC system for marine applications fuelled with methane methanol diesel ammonia or hydrogen. In addition cathode off-gas recirculation (COGR) is investigated to tackle low oxygen utilisation and thus improve heat regeneration. The software Cycle Tempo is used to simulate the power plant which uses a 1D model for the SOFCs. At nominal conditions the highest net electrical efficiency (LHV) was found for methane (58.1%) followed by diesel (57.6%) and ammonia (55.1%). The highest heat efficiency was found for ammonia (27.4%) followed by hydrogen (25.6%). COGR resulted in similar electrical efficiencies but increased the heat efficiency by 11.9% to 105.0% for the different fuels. The model was verified with a sensitivity analysis and validated by comparison with similar studies. It is concluded that COGR is a promising method to increase the heat efficiency of marine SOFC systems.
Study on the Effect of Second Injection Timing on the Engine Performances of a Gasoline/Hydrogen SI Engine with Split Hydrogen Direct Injecting
Oct 2020
Publication
Split hydrogen direct injection (SHDI) has been proved capable of better efficiency and fewer emissions. Therefore to investigate SHDI deeply a numerical study on the effect of second injection timing was presented at a gasoline/hydrogen spark ignition (SI) engine with SHDI. With an excess air ratio of 1.5 five different second injection timings achieved five kinds of hydrogen mixture distribution (HMD) which was the main factor affecting the engine performances. With SHDI since the HMD is manageable the engine can achieve better efficiency and fewer emissions. When the second injection timing was 105◦ crank angle (CA) before top dead center (BTDC) the Pmax was the highest and the position of the Pmax was the earliest. Compared with the single hydrogen direct injection (HDI) the NOX CO and HC emissions with SHDI were reduced by 20% 40% and 72% respectively.
Environmental Assessment of Hydrogen Utilization in Various Applications and Alternative Renewable Sources for Hydrogen Production: A Review
May 2023
Publication
Rapid industrialization is consuming too much energy and non-renewable energy resources are currently supplying the world’s majority of energy requirements. As a result the global energy mix is being pushed towards renewable and sustainable energy sources by the world’s future energy plan and climate change. Thus hydrogen has been suggested as a potential energy source for sustainable development. Currently the production of hydrogen from fossil fuels is dominant in the world and its utilization is increasing daily. As discussed in the paper a large amount of hydrogen is used in rocket engines oil refining ammonia production and many other processes. This paper also analyzes the environmental impacts of hydrogen utilization in various applications such as iron and steel production rocket engines ammonia production and hydrogenation. It is predicted that all of our fossil fuels will run out soon if we continue to consume them at our current pace of consumption. Hydrogen is only ecologically friendly when it is produced from renewable energy. Therefore a transition towards hydrogen production from renewable energy resources such as solar geothermal and wind is necessary. However many things need to be achieved before we can transition from a fossil-fuel-driven economy to one based on renewable energy
Potential Global Warming Impact of 1 kW Polymer Electrolyte Membrane Fuel Cell System for Residential Buildings on Operation Phase
Mar 2023
Publication
This study established global warming potential(GWP) emission factors through a life cycle assessment on the operation phases of two different 1 kW polymer electrolyte membrane fuel cell (PEMFC) systems for residential buildings (NG-PEMFC fed with hydrogen from natural gas reforming; WE-PEMFC fed with hydrogen from photovoltaics-powered water electrolyzer). Their effectiveness was also compared with conventional power grid systems in Korea specifically in the area of greenhouse gas emissions. The operation phases of the NG-PEMFC and the WE-PEMFC were divided into burner reformer and stack and into water electrolysis and stack respectively. The functional unit of each fuel cell system was defined as 1 kWh of electricity production. In the case of NG-PEMFC the GWP was 3.72E-01 kg-CO2eq/kWh the embodied carbon emissions due to using city gas during the life cycle process was about 20.87 % the carbon emission ratio according to the reformer's combustion burner was 6.07 % and the direct carbon emission ratio of the air emissions from the reformer was 73.06 % indicating that the carbon emission from the reformer contributed over 80 % of the total GWP. As for the WE-PEMFC the GWP was 1.76E-01 kg-CO2eq/kWh and the embodied carbon emissions from photovoltaic power generation during the life cycle process contributed over 99 % of the total GWP.
Potential Role of Renewable Gas in the Transition of Electricity and District Heating Systems
Dec 2019
Publication
With the constant increase in variable renewable energy production in electricity and district heating systems integration with the gas system is a way to provide flexibility to the overall energy system. In the sustainable transition towards a zero-emission energy system traditional natural gas can be substituted by renewable gasses derived from anaerobic digestion or thermal gasification and hydrogen. In this paper we present a methodology for modelling renewable gas options and limits on biomass resources across sectors in the energy optimisation model Balmorel. Different scenarios for socio-economic pathways to emission neutral electricity and district heating systems in Denmark Sweden Norway and Germany show that a renewable based energy system benefits from a certain percentage of gas as a supplement to other flexibility options like interconnectors. Especially upgraded biogas from anaerobic digestion serves as a substitute for natural gas in all scenarios. Allocating only 10% of available biomass to the electricity and district heating sector leads to full exploitation of the scarce biomass resource by boosting biogas and syngas with hydrogen. The need for renewable gasses is highest in Germany and least in Norway where hydro-power provides flexibility in terms of storable and dispatchable electricity production. The scenarios show that a required ‘‘late sprint" from fossils to achieve a zero-emission energy system in 2050 causes (1) significant higher accumulated emissions and (2) a system which strongly relies on fuels also in an emission free system instead of stronger integration of the electricity and district heating systems through electrification as well as stronger integration of the power systems across countries through interconnectors.
Moving Toward the Low-carbon Hydrogen Economy: Experiences and Key Learnings from National Case Studies
Sep 2022
Publication
The urgency to achieve net-zero carbon dioxide (CO2) emissions by 2050 as first presented by the IPCC special report on 1.5°C Global Warming has spurred renewed interest in hydrogen to complement electrification for widespread decarbonization of the economy. We present reflections on estimates of future hydrogen demand optimization of infrastructure for hydrogen production transport and storage development of viable business cases and environmental impact evaluations using life cycle assessments. We highlight challenges and opportunities that are common across studies of the business cases for hydrogen in Germany the UK the Netherlands Switzerland and Norway. The use of hydrogen in the industrial sector is an important driver and could incentivise large-scale hydrogen value chains. In the long-term hydrogen becomes important also for the transport sector. Hydrogen production from natural gas with capture and permanent storage of the produced CO2 (CCS) enables large-scale hydrogen production in the intermediate future and is complementary to hydrogen from renewable power. Furthermore timely establishment of hydrogen and CO2 infrastructures serves as an anchor to support the deployment of carbon dioxide removal technologies such as direct air carbon capture and storage (DACCS) and biohydrogen production with CCS. Significant public support is needed to ensure coordinated planning governance and the establishment of supportive regulatory frameworks which foster the growth of hydrogen markets.
Pressure Management in Smart Gas Networks for Increasing Hydrogen Blending
Jan 2022
Publication
The injection of hydrogen into existing gas grids is acknowledged as a promising option for decarbonizing gas systems and enhancing the integration among energy sectors. Nevertheless it affects the hydraulics and the quality management of networks. When the network is fed by multiple infeed sites and hydrogen is fed from a single injection point non-homogeneous hydrogen distribution throughout the grid happens to lead to a reduction of the possible amount of hydrogen to be safely injected within the grid. To mitigate these impacts novel operational schemes should therefore be implemented. In the present work the modulation of the outlet pressures of gas infeed sites is proposed as an effective strategy to accommodate larger hydrogen volumes into gas grids extending the area of the network reached by hydrogen while keeping compliance with quality and hydraulic restrictions. A distribution network operated at two cascading pressure tiers interfaced by pressure regulators constitutes the case study which is simulated by a fluid-dynamic and multi-component model for gas networks. Results suggest that higher shares of hydrogen and other green gases can be introduced into existing distribution systems by implementing novel asset management schemes with negligible impact on grid operations.
Just Energy Transition: Learning from the Past for a More Just and Sustainable Hydrogen Transition in West Africa
Dec 2022
Publication
The rising demand for energy and the aim of moving away from fossil fuels and to low-carbon power have led many countries to move to alternative sources including solar energy wind geothermal energy biomass and hydrogen. Hydrogen is often considered a “missing link” in guaranteeing the energy transition providing storage and covering the volatility and intermittency of renewable energy generation. However due to potential injustice with regard to the distribution of risks benefits and costs (i.e. in regard to competing for land use) the large-scale deployment of hydrogen is a contested policy issue. This paper draws from a historical analysis of past energy projects to contribute to a more informed policy-making process toward a more just transition to the hydrogen economy. We perform a systematic literature review to identify relevant conflict factors that can influence the outcome of hydrogen energy transition projects in selected Economic Community of West African States countries namely Nigeria and Mali. To better address potential challenges policymakers must not only facilitate technology development access and market structures for hydrogen energy policies but also focus on energy access to affected communities. Further research should monitor hydrogen implementation with a special focus on societal impacts in producing countries.
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.
Analysis of CO2 Emissions Reduction on the Future Hydrogen Supply Chain Network for Dubai Buses
Apr 2023
Publication
There is an impetus to decarbonize transportation sector and mitigate climate change. This study examines the effect of adopting hydrogen (H2) as a fuel for Dubai Buses at different penetration scales on carbon dioxide (CO2) emissions reduction. A H2 supply-chain system dynamics model is developed to conduct life cycle cost and environmental analysis and evaluate the efficacy of different carbon prices and subsidies. Gray green and mixed H2 production scenarios were considered. The results show that gray hydrogen reduces 7.1 million tons of CO2 which is half of green hydrogen buses. Replacing diesel fleet at end of lifetime with mixed hydrogen bus fleet was the optimal approach to promote green hydrogen at pump reaching $4/kg in a decade. This gradual transition reduces 62% of the well-to-wheel CO2 emissions of the new bus fleet and creates mass for economies of scale as carbon prices and subsidies cannot promote green hydrogen alone.
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