Germany
Assessment of a Coupled Electricity and Hydrogen Sector in the Texas Energy System in 2050
Oct 2024
Publication
Due to its ability to reduce emissions in the hard-to-abate sectors hydrogen is expected to play a significant role in future energy systems. This study modifies a sector-coupled dynamic modeling framework for electricity and hydrogen by including policy constraints carbon prices and possible hydrogen pathways and applies it to Texas in 2050. The impact of financial policies including the US clean hydrogen production tax credit on required infrastructure and costs are explored. Due to low natural gas prices financial levers are necessary to promote low-carbon hydrogen production as the optimized solution. The Levelized Costs of Hydrogen are found to be $1.50/kg in the base case (primarily via steam methane reformation production) and lie between $2.10 - 3.10/kg when production is via renewable electrolysis. The supporting infrastructure required to supply those volumes of renewable hydrogen is immense. The hydrogen tax credit was found to be enough to drive production via electrolysis.
Green Hydrogen Cooperation between Egypt and Europe: The Perspective of Locals in Suez and Port Said
Jun 2024
Publication
Hydrogen produced by renewable energy sources (green hydrogen) is at the centrepiece of European decarbonization strategies necessitating large imports from third countries. Egypt potentially stands out as major production hub. While technical and economic viability are broadly discussed in literature analyses of local acceptance are absent. This study closes this gap by surveying 505 locals in the Suez Canal Economic Zone (Port Said and Suez) regarding their attitudes towards renewable energy development and green hydrogen production. We find overall support for both national deployment and export to Europe. Respondents see a key benefit in rising income thereby strongly underlying the economic argument. Improved trade relationships or improved political relationships are seen as potential benefits of export but as less relevant for engaging in cooperation putting a spotlight on local benefits. Our study suggests that the local population is more positive than negative towards the development and scaling up of green hydrogen projects in Egypt.
Mapping Local Green Hydrogen Cost-potentials by a Multidisciplinary Approach
Sep 2024
Publication
S. Ishmam,
Heidi Heinrichs,
C. Winkler,
B. Bayat,
Amin Lahnaoui,
Solomon Nwabueze Agbo,
E.U. Pena Sanchez,
David Franzmann,
N. Oijeabou,
C. Koerner,
Y. Michael,
B. Oloruntoba,
C. Montzka,
H. Vereecken,
H. Hendricks Franssen,
J. Brendtf,
S. Brauner,
W. Kuckshinrichs,
S. Venghaus,
Daouda Kone,
Bruno Korgo,
Kehinde Olufunso Ogunjobi,
V. Chiteculo,
Jane Olwoch,
Z. Getenga,
Jochen Linßen and
Detlef Stolten
For fast-tracking climate change response green hydrogen is key for achieving greenhouse gas neutral energy systems. Especially Sub-Saharan Africa can benefit from it enabling an increased access to clean energy through utilizing its beneficial conditions for renewable energies. However developing green hydrogen strategies for Sub-Saharan Africa requires highly detailed and consistent information ranging from technical environmental economic and social dimensions which is currently lacking in literature. Therefore this paper provides a comprehensive novel approach embedding the required range of disciplines to analyze green hydrogen costpotentials in Sub-Saharan Africa. This approach stretches from a dedicated land eligibility based on local preferences a location specific renewable energy simulation locally derived sustainable groundwater limitations under climate change an optimization of local hydrogen energy systems and a socio-economic indicator-based impact analysis. The capability of the approach is shown for case study regions in Sub-Saharan Africa highlighting the need for a unified interdisciplinary 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.
A Review of Life Cycle Assessment (LCA) Studies for Hydrogen Production Technologies through Water Electrolysis: Recent Advances
Aug 2024
Publication
Climate change is a major concern for the sustainable development of global energy systems. Hydrogen produced through water electrolysis offers a crucial solution by storing and generating renewable energy with minimal environmental impact thereby reducing carbon emissions in the energy sector. Our research evaluates current hydrogen production technologies such as alkaline water electrolysis (AWE) proton exchange membrane water electrolysis (PEMWE) solid oxide electrolysis (SOEC) and anion exchange membrane water electrolysis (AEMWE). We systematically review life cycle assessments (LCA) for these technologies analyzing their environmental impacts and recent technological advancements. This study fills essential gaps by providing detailed LCAs for emerging technologies and evaluating their scalability and environmental footprints. Our analysis outlines the strengths and weaknesses of each technology guiding future research and assisting stakeholders in making informed decisions about integrating hydrogen production into the global energy mix. Our approach highlights operational efficiencies and potential sustainability enhancements by employing comparative analyses and reviewing advancements in membrane technology and electrocatalysts. A significant finding is that PEMWE when integrated with renewable energy sources offers rapid response capabilities that are vital for adaptive energy systems and reducing carbon footprints.
Life Cycle Costing Approaches of Fuel Cell and Hydrogen Systems: A Literature Review
Apr 2023
Publication
Hydrogen is a versatile energy carrier which can be produced from variety of feedstocks stored and transported in various forms for multi-functional end-uses in transportation energy and manufacturing sectors. Several regional national and supra-national climate policy frameworks emphasize the need value and importance of Fuel cell and Hydrogen (FCH) technologies for deep and sector-wide decarbonization. Despite these multi-faceted advantages familiar and proven FCH technologies such as alkaline electrolysis and proton-exchange membrane fuel cell (PEMFC) often face economic technical and societal barriers to mass-market adoption. There is no single unified standardized and globally harmonized normative definition of costs. Nevertheless the discussion and debates surrounding plausible candidates and/or constituents integral for assessing the economics and value proposition of status-quo as well as developmental FCH technologies are steadily increasing—Life Cycle Costing (LCC) being one of them if not the most important outcome of such exercises.<br/>To that end this review article seeks to improve our collective understanding of LCC of FCH technologies by scrutinizing close to a few hundred publications drawn from representative databases—SCOPUS and Web of Science encompassing several tens of technologies for production and select transportation storage and end-user utilization cases. This comprehensive review forms part of and serves as the basis for the Clean Hydrogen Partnership funded SH2E project whose ultimate goal is the methodical development a formal set of principles and guardrails for evaluating the economic environmental and social impacts of FCH technologies. Additionally the SH2E projects will also facilitate the proper comparison of different FCH technologies whilst reconciling range of technologies methodologies modelling assumptions and parameterization found in existing literature.
Assessment of the Green Hydrogen Value Chain in Cases of the Local Industry in Chile Applying an Optimization Model
May 2024
Publication
This study assessed the feasibility of integrating a green hydrogen value chain into the local industry examining two case studies by comparing four scenarios. The optimization focused on generating electricity from stationary renewable sources such as solar or through Power Purchase Agreements to produce sufficient hydrogen in electrolyzers. Current demand profiles renewable participation targets electricity supply sources levelized costs of energy and hydrogen and technology options were considered. The most cost-effective scenario showed a levelized cost of energy of 0.032 and 0.05 US$/kWh and a hydrogen cost below 1.0 US$/kgH2 for cases 1 and 2 respectively. A sensitivity analysis highlighted the critical influence of fuel cell technology on cost modification underscoring the importance of focusing cost reduction strategies on these technologies to enhance the economic viability of the green hydrogen value chain. Specifically a high sensitivity towards reducing the levelized costs of energy and hydrogen in the port sector with adjustments in fuel cell technology costs was identified indicating the need for specific policies and supports to facilitate their adoption.
Advancing Life Cycle Assessment of Sustainable Green Hydrogen Production Using Domain-Specific Fine-Tuning by Large Language Models Augmentation
Nov 2024
Publication
Assessing the sustainable development of green hydrogen and assessing its potential environmental impacts using the Life Cycle Assessment is crucial. Challenges in LCA like missing environmental data are often addressed using machine learning such as artificial neural networks. However to find an ML solution researchers need to read extensive literature or consult experts. This research demonstrates how customised LLMs trained with domain-specific papers can help researchers overcome these challenges. By starting small by consolidating papers focused on the LCA of proton exchange membrane water electrolysis which produces green hydrogen and ML applications in LCA. These papers are uploaded to OpenAI to create the LlamaIndex enabling future queries. Using the LangChain framework researchers query the customised model (GPT-3.5-turbo) receiving tailored responses. The results demonstrate that customised LLMs can assist researchers in providing suitable ML solutions to address data inaccuracies and gaps. The ability to quickly query an LLM and receive an integrated response across relevant sources presents an improvement over manually retrieving and reading individual papers. This shows that leveraging fine-tuned LLMs can empower researchers to conduct LCAs more efficiently and effectively.
Electrification or Hydrogen? The Challenge of Decarbonizing Industrial (High-Temperature) Process Heat
Oct 2024
Publication
The decarbonization of industrial process heat is one of the bigger challenges of the global energy transition. Process heating accounts for about 20% of final energy demand in Germany and the situation is similar in other industrialized nations around the globe. Process heating is indispensable in the manufacturing processes of products and materials encountered every day ranging from food beverages paper and textiles to metals ceramics glass and cement. At the same time process heating is also responsible for significant greenhouse gas emissions as it is heavily dependent on fossil fuels such as natural gas and coal. Thus process heating needs to be decarbonized. This review article explores the challenges of decarbonizing industrial process heat and then discusses two of the most promising options the use of electric heating technologies and the substitution of fossil fuels with low-carbon hydrogen in more detail. Both energy carriers have their specific benefits and drawbacks that have to be considered in the context of industrial decarbonization but also in terms of necessary energy infrastructures. The focus is on high-temperature process heat (>400 ◦C) in energy-intensive basic materials industries with examples from the metal and glass industries. Given the heterogeneity of industrial process heating both electricity and hydrogen will likely be the most prominent energy carriers for decarbonized high-temperature process heat each with their respective advantages and disadvantages.
Cost-optimal Design and Operation of Hydrogen Refueling Stations with Mechanical and Electrochemical Hydrogen Compressors
Sep 2024
Publication
Hydrogen refueling stations (HRS) can cause a significant fraction of the hydrogen refueling cost. The main cost contributor is the currently used mechanical compressor. Electrochemical hydrogen compression (EHC) has recently been proposed as an alternative. However its optimal integration in an HRS has yet to be investigated. In this study we compare the performance of a gaseous HRS equipped with different compressors. First we develop dynamic models of three process configurations which differ in the compressor technology: mechanical vs. electrochemical vs. combined. Then the design and operation of the compressors are optimized by solving multi-stage dynamic optimization problems. The optimization results show that the three configurations lead to comparable hydrogen dispensing costs because the electrochemical configuration exhibits lower capital cost but higher energy demand and thus operating cost than the mechanical configuration. The combined configuration is a trade-off with intermediate capital and operating cost.
Perspective on the Development and Integration of Hydrogen Sensors for Fuel Cell Control
Oct 2024
Publication
The measurement of hydrogen concentration in fuel cell systems is an important prerequisite for the development of a control strategy to enhance system performance reduce purge losses and minimize fuel cell aging effects. In this perspective paper the working principles of hydrogen sensors are analyzed and their requirements for hydrogen control in fuel cell systems are critically discussed. The wide measurement range absence of oxygen high humidity and limited space turn out to be most limiting. A perspective on the development of hydrogen sensors based on palladium as a gas-sensitive metal and based on the organic magnetic field effect in organic lightemitting devices is presented. The design of a test chamber where the sensor response can easily be analyzed under fuel cell-like conditions is proposed. This allows the generation of practical knowledge for further sensor development. The presented sensors could be integrated into the end plate to measure the hydrogen concentration at the anode in- and outlet. Further miniaturization is necessary to integrate them into the flow field of the fuel cell to avoid fuel starvation in each single cell. Compressed sensing methods are used for more efficient data analysis. By using a dynamical sensor model control algorithms are applied with high frequency to control the hydrogen concentration the purge process and the recirculation pump.
Closed Loop Model Predictive Control of a Hybrid Battery-Hydrogen Energy Storage System using Mixed-Integer Linear Programming
Mar 2024
Publication
The derivation of an efficient operational strategy for storing intermittent renewable energies using a hybrid battery-hydrogen energy storage system is a difficult task. One approach for deriving an efficient operational strategy is using mathematical optimization in the context of model predictive control. However mathematical optimization derives an operational strategy based on a non-exact mathematical system representation for a specified prediction horizon to optimize a specified target. Thus the resulting operational strategies can vary depending on the optimization settings. This work focuses on evaluating potential improvements in the operational strategy for a hybrid batteryhydrogen energy storage system using mathematical optimization. To investigate the operation a simulation model of a hybrid energy storage system and a tailor-made mixed integer linear programming optimization model of this specific system are utilized in the context of a model predictive control framework. The resulting operational strategies for different settings of the model predictive control framework are compared to a rule-based controller to show the potential benefits of model predictive control compared to a conventional approach. Furthermore an in-depth analysis of different factors that impact the effectiveness of the model predictive controller is done. Therefore a sensitivity analysis of the effect of different electricity demands and resource sizes on the performance relative to a rule-based controller is conducted. The model predictive controller reduced the energy consumption by at least 3.9 % and up to 17.9% compared to a rule-based controller. Finally Pareto fronts for multi-objective optimizations with different prediction and control horizons are derived and compared to the results of a rule-based controller. A cost reduction of up to 47 % is achieved by a model predictive controller with a prediction horizon of 7 days and perfect foresight. Keywords: Model Predictive Control Optimization Mixed Integer Linear Programming Hybrid Battery-Hydrogen Energy Storage System
Green Hydrogen Transitions Deepen Socioecological Risks and Extractivist Patterns: Evidence from 28 Perspective Exporting Countries in the Global South
Sep 2024
Publication
The global green hydrogen rush is prone to repeat extractivist patterns at the expense of economies ecologies and communities in the production zones in the Global South. With a socio-ecological risk analysis grounded in energy water and environmental justice scholarship we systematically assess the risks of the ‘green’ hydrogen transition and related injustices arising in 28 countries in the Global South with regard to energy water land and global justice dimensions. Our findings show that risks materialize through the exclusion of affected communities and civil society the enclosure of land and resources for extractivist purposes and through the externalization of socio-ecological costs and conflicts. We further demonstrate that socio-ecological risks are enhanced through country-specific conditions such as water scarcity historical continuities such as post-colonial land tenure systems as well as repercussions of a persistently uneven global politico-economic order. Contributing to debates on power inequality and justice in the global green hydrogen transition we argue that addressing hydrogen risks requires a framework of environmental justice and a transformative perspective that encompasses structural shifts in the global economy including degrowth and a decentering of industrial hegemonies in the Global North.
Safety of Hydrogen Storage Technologies
Oct 2024
Publication
While hydrogen is regularly discussed as a possible option for storing regenerative energies its low minimum ignition energy and broad range of explosive concentrations pose safety challenges regarding hydrogen storage and there are also challenges related to hydrogen production and transport and at the point of use. A risk assessment of the whole hydrogen energy system is necessary to develop hydrogen utilization further. Here we concentrate on the most important hydrogen storage technologies especially high-pressure storage liquid hydrogen in cryogenic tanks methanol storage and salt cavern storage. This review aims to study the most recent research results related to these storage techniques by describing typical sensors and explosion protection measures thus allowing for a risk assessment of hydrogen storage through these technologies.
19 Import Options for Green Hydrogen and Derivatives - An Overview of Efficiencies and Technology Readiness Levels
Oct 2024
Publication
The import of hydrogen and derivatives forms part of many national strategies and is fundamental to achieving climate protection targets. This paper provides an overview and technical comparison of import pathways for hydrogen and derivatives in terms of efficiency technological maturity and development and construction times with a focus on the period up to 2030. The import of hydrogen via pipeline has the highest system efficiency at 57–67 % and the highest technological maturity with a technology readiness level (TRL) of 8–9. The import of ammonia and methanol via ship and of SNG via pipeline shows efficiencies in the range of 39–64 % and a technological maturity of TRL 7 to 9 when using point sources. Liquid hydrogen LOHC and Fischer-Tropsch products have the lowest efficiency and TRL in comparison. The use of direct air capture (DAC) reduces efficiency and TRL considerably. Reconversion of the derivatives to hydrogen is also associated with high losses and is not achievable for all technologies on an industrial scale up to 2030. In the short to medium term import routes for derivatives that can utilise existing infrastructures and mature technologies are the most promising for imports. In the long term the most promising option is hydrogen via pipelines.
Hydrogen Sampling Systems Adapted to Heavy-duty Refuelling Stations' Current and Future Specifications - A Review
Sep 2024
Publication
To meet the new regulation for the deployment of alternative fuels infrastructure which sets targets for electric recharging and hydrogen refuelling infrastructure by 2025 or 2030 a large infrastructure comprising trucksuitable hydrogen refuelling stations will soon be required. However further standardisation is required to support the uptake of hydrogen for heavy-duty transport for Europe’s green energy future. Hydrogen-powered vehicles require pure hydrogen as some contaminants can reduce the performance of the fuel cell even at very low levels. Even if previous projects have paved the way for the development of the European quality infrastructure for hydrogen conformity assessment sampling systems and methods have yet to be developed for heavy-duty hydrogen refuelling stations (HD-HRS). This study reviews different aspects of the sampling of hydrogen at heavy-duty hydrogen refuelling stations for purity assessment with a focus on the current and future specifications and operations at HD-HRS. This study describes the state-of-the art of sampling systems currently under development for use at HD-HRS and highlights a number of aspects which must be taken into consideration to ensure safe and accurate sampling: risk assessment for the whole sampling exercise selection of cylinders methods to prepare cylinders before the sampling filling pressure and venting of the sampling systems.
Hydrogen Production from Wastewater: A Comprehensive Review of Conventional and Solar Powered Technologies
Mar 2024
Publication
The need to reduce the carbon footprint of conventional energy sources has made green hydrogen a promising solution for the energy transition. The most environmentally friendly way to produce hydrogen is through water-based production using renewable energy. However the availability of fresh water is limited so switching to wastewater instead of fresh water is the key solution to this problem. In response to this issue the present review reports the main findings of the research studies dealing with the feasibility of hydrogen production from wastewater using various technologies including biological electrochemical and advanced oxidation routes. These methods have been studied in a large number of experiments with the aim of investigating and improving the potential of each method. On the other hand the maturity of solar energy technologies has led researchers to focus on the possibility of harnessing this source and combining it with wastewater treatment techniques for the production of green hydrogen. Therefore the present review pays special attention to solar driven hydrogen production from wastewater by highlighting the potential of several technologies for simultaneous water treatment and green hydrogen production from wastewater. Recent results limitations challenges possible improvements and techno-economic assessments reported by several authors as well as future directions of research and industrial implementation in this field are reported.
Generalized Thermodynamic Modelling of Hydrogen Storage Tankes for Truck Application
Mar 2024
Publication
Hydrogen-driven heavy-duty trucks are a promising technology for reducing CO2 emissions in the transportation sector. Thus storing hydrogen efficiently onboard is vital. The three available or currently developed physical hydrogen storage technologies (compressed gaseous subcooled liquid and cryo-compressed hydrogen) are promising solutions. For a profound thermodynamic comparison of these storage systems a universally applicable model is required. Thus this article introduces a generalized thermodynamic model and conducts thermodynamic comparisons in terms of typical drive cycle scenarios. Therefore a model introduced by Hamacher et al. [1] for cryo-compressed hydrogen tanks is generalized by means of an explicit model formulation using the property ��2� from REFPROP [2] which is understood as a generic specific isochoric two-phase heat capacity. Due to an implemented decision logic minor changes to the equation system are automatically made whenever the operation mode or phase of the tank changes. The resulting model can simulate all three storage tank systems in all operating scenarios and conditions in the single- and two-phase region. Additionally the explicit model formulation provides deeper insights into the thermodynamic processes in the tank. The model is applied to the three physical hydrogen storage technologies to compare drive cycles heat requirement dormancy behavior and optimal usable density. The highest driving ranges were achieved with cryo-compressed hydrogen however it also comes with higher heating requirements compared to subcooled liquid hydrogen.
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