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Item type:Publication, Access status: with files , Optimization-based integration of a metal hydride storage in a residential energy system – A techno-economic analysisThe increased use of electrified heating systems in residential buildings places additional demands on the power grid, alongside the growing load from, e.g., photovoltaic power. One solution to relieve the strain on the power grid could be to increase the energy autarky of residential buildings by increasing the consumption of self-generated electricity. Higher self-consumption requires an energy storage system that is capable of storing large amounts of electricity (seasonally). Metal hydride storage systems could be a technically feasible solution. Excess heat from the metal hydride storage tank could contribute to the heating system and further reduce electricity consumption. This study aims to investigate the extent to which a metal hydride storage system can be used in a single-family house to relieve stress on the power grid significantly. To investigate this novel approach, a design and operation optimization is performed to determine the most cost-effective system configuration at maximum autarky level. Compared to a reference case with no seasonal energy storage, the autarky level could be increased by integrating a metal hydride storage system by 27%-points to 79% resulting in a feed-in reduction of 35% into the superior power grid. In addition, grid electricity consumption can be reduced by up to 45%. However, such a system results in a 4.3-fold increase in total annual costs. Even with positive developments in the future (technological and economic), this factor can only be reduced to 2.5. Independent of the clear cost increase under current cost relations, the integration of metal hydride storage systems into a future home energy system is a technically viable option.Publicationtype: Journal Article16 24 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Comparison of the design and operation of various fossil-free ferry topologies with a conventional diesel-powered propulsion system – An optimization-based techno-economic-environmental analysisTo meet global greenhouse gas (GHG) reduction goals, the shipping sector must also be defossilized. Hydrogen-powered systems could be particularly advantageous for short- and medium-range routes, such as ferries for river or strait crossings. For such applications, metal hydrides offer a promising way to store the hydrogen needed to power the respective ship's propulsion system. In such metal hydrides, hydrogen can be stored safely and without any storage losses under ambient conditions (pressure/temperature). To evaluate the suitability of these metal hydride storage systems as part of a hydrogen-powered propulsion system on ships, the design and operation of ships with metal hydride storage systems must be examined in direct comparison with battery-driven and diesel-powered systems. Therefore, the overarching goal of this paper is based on an optimization-based approach to investigate how a metal hydride system can be operated and designed in a technically and economically viable manner. Furthermore, the environmental performance resulting from such a system is analyzed. The findings show that fuel costs (hydrogen system: 92%, battery system: 85% of total costs) significantly affect the economic viability. Compared to a battery-powered system and a diesel-driven system, the hydrogen-powered system requires the least amount of space. It remains a viable option even with less favorable discharge rates (ranging from 0.03 to 1.0 kW/kWh) of the metal hydride storage system. Thus, if the hydrogen fuel costs decline in the future, such a hydrogen-powered propulsion system for ships could be an alternative to pure battery-based systems. Additionally, the hydrogen-powered system can significantly reduce greenhouse gas emissions compared to a diesel-powered system as long as “green” hydrogen is used.Publicationtype: Journal Article9 13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Preheating options for novel design concepts for metal hydride storage tanks – Numerical modeling, simulation and evaluation(2025-06); ; ; ; Publicationtype: Conference Poster52 16 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Zusammenfassung und AusblickIm Jahr 2024 konnte insgesamt eine Zunahme derNutzung des erneuerbaren Energieangebots innerhalb des Energiesystems in Deutschland festgestellt werden. Jedoch zeigen sich nach wie vor deutliche Unterschiede zwischen den Bereichen Strom, Wärme und Mobilität sowohl in Bezug auf die absolute Nutzung als auch hinsichtlich der aktuellen Entwicklungen.Publicationtype: Book Part20 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , RahmenbedingungenZiel der folgenden Ausführungen ist eine Darstellung der natürlichen und Menschgemachten Rahmenbedingungen, die eine Nutzung des erneuerbaren Energieangebots in Deutschland (mit-)bestimmen. Dazu wird zunächst das natürliche regenerative Energieangebot – und hier im Wesentlichen die solare Einstrahlung, die durchschnittlichen Windgeschwindigkeiten und die entsprechenden Niederschläge – adressiert. Zusätzlich wird auf die mittleren Temperaturen eingegangen, die insbesondere die Nachfrage nach Raumwärme und ggf. -kälte determinieren.Publicationtype: Book Part21 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Wärmebereitstellung aus erneuerbaren Energien(Springer, 2025-04-26); ; ; ; Im folgenden Kapitel wird ein Überblick über die wichtigsten Optionen zur Bereitstellung von Wärme aus erneuerbaren Energien gegeben. Die dominierende Technologie ist dabei die Biomassenutzung – und hier insbesondere die Nutzung von biogenen Festbrennstoffen. In den vergangenen Jahren stieg zudem der Anteil der Umweltwärmenutzung (d. h. Wärmepumpenapplikation) deutlich an – und das mit einem anhaltendem Trend.Publicationtype: Book Part18 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Erneuerbare Energien in Deutschland 2024(Springer, 2025-04-25); ; ; ; Die Herausgeber bieten eine Zusammenstellung der Nutzung des erneuerbaren Energieangebots in Deutschland im Jahr 2024. Zuerst ist die energiewirtschaftliche Gesamtsituation dargestellt und anschließend der aktuelle Stand der Nutzung der regenerativen Energien in Deutschland, einschließlich der wichtigsten Entwicklungen. Sowohl die Optionen zur primären Strom- und Wärmebereitstellung - einschließlich der Möglichkeiten einer KWK – als auch die Varianten einer Bereitstellung alternativer / erneuerbarer Kraftstoffe für den Verkehrssektor sind diskutiert. Darüber hinaus sind die Perspektiven marktbestimmender Technologien innerhalb der Sektoren Strom, Wärme und Mobilität analysiert. Das Buch bietet außerdem kurze Einblicke in das existierende und das potenziell zukünftige legale Regelwerk, die Integration der erneuerbaren Energien in unser Wirtschaftssystem sowie die sie determinierenden ökonomischen Rahmenbedingungen.Publicationtype: Book43 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Novel concepts for metal hydride storage tanks – numerical modeling, simulation and evaluation(Elsevier, 2025-01-31); ; ; ; The efficient, space-saving and safe storage of hydrogen is a major challenge that needs to be overcome for enabling renewable energy systems. Metal hydrides are a possible solution. But the key challenge is the identification and development of the most promising metal hydride material as well as the ideal tank design for an efficient hydrogen absorption / desorption in terms of energy demand / storage losses and loading / unloading time. Against this background this paper aims to identify suitable combinations of medium and low-temperature metal hydride materials in combination with three different tank design concepts. The goal is to determine which material fits best for each combination and could thus be a suitable solution for a future implementation in stationary and mobile applications of metal hydride storage tanks. To achieve this goal a finite element method (FEM) modeling and simulation of materials and construction designs in COMSOL Multiphysics is realized. The results are analyzed in terms of hydrogen absorption rate, temperature profile over time, and the necessary energy demand for the overall storage process. The results show that for the low-temperature metal hydride investigated here, the tank design is of subordinate importance, allowing for more application-specific design. For medium-temperature metal hydrides, the investigated construction concepts show heterogeneous results. For fast hydrogen absorption and minimal external heating time, the suggested rectangular tank design might be a promising option, requiring only 28% / 29% of the heating energy of the cylindrical concepts. If the goal is to achieve the most complete hydrogen absorption, the base design concept investigated here, consisting of a cylindrical tank with metal hydride material rolled up in a spiral, is the most favorable solution; achieving a hydrogen loading of about 3.6 wt–% for the medium-temperature metal hydride. The low-temperature metal hydride achieves a total hydrogen absorption of around 1.4 wt-% in the optimum concept. For concepts with higher operating temperatures, preheating the storage tank before feeding in the hydrogen could improve the absorption process (only examined here).Publicationtype: Journal Article41 42 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Power and biogas to methanol – a techno-economic analysis of carbon-maximized green methanol production via two reforming approachesThe limited potential of sustainably available biomass requires efficient conversion to defossilize future demands of carbon-based chemicals and energy carriers. Therefore, integrating electricity-derived hydrogen into biomass-based production concepts appears promising, maximizing carbon utilization while minimizing biomass requirement. However, specific process concepts and analyses are still lacking to quantify the potential technical and economic benefits of such hybrid production processes. Thus, this research paper investigates this novel approach for decentralized methanol production from biogas within a techno-economic analysis, considering two production configurations. One configuration (BiRef) utilizes electrically heated bi-reforming for syngas generation, while the other configuration (TriRef) uses autothermal tri-reforming. Based on stationary process simulations, in-depth knowledge about process behavior is gained, efficiencies and costs are determined, and influencing factors are assessed. Within the reference case, the BiRef configuration achieves a carbon efficiency of 93 %, while the TriRef configuration reaches 97 % due to its enhanced methane conversion. Energy efficiency is 5 %pt. higher within the BiRef configuration (74 %), primarily due to the lower hydrogen demand. Carbon and energy efficiency are crucially affected by reforming temperature and inert gas fraction in the syngas. The economic analysis shows methanol production costs of ca. 1,300 €2022/t for both configurations. Variations in economic parameters emphasize advantages for the TriRef configuration when low hydrogen costs (<6 €2022/kg) are achievable. The comparison with purely biogas-based methanol production shows that hydrogen addition increases production capacity by up to 67 %. Cost advantages result against purely electricity-based production, while cost parity is achieved with purely biogas-based production. This paper demonstrates the potential of hybrid methanol production for efficient biogas utilization and highlights decisive parameters influencing technical and economic efficiency.Publicationtype: Journal ArticleScopus© Citations 2 70 95 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Life cycle assessment of construction and driving operation of a hydrogen-powered truck built from a used diesel truckOne option to reduce greenhouse gas (GHG) emissions from heavy-duty vehicles is switching to hydrogen as a fuel, which is converted in drive trains powered by fuel cells. In addition to the production of new hydrogen trucks, it is also possible to convert used diesel-powered trucks to hydrogen-powered vehicles. This paper aims to evaluate the environmental impact of a heavy-duty truck converted from diesel propulsion to a hydrogen fuel cell drive regarding life-cycle GHG emissions and mineral resource scarcity (MRS). This life cycle assessment focuses on the construction and end-of-life phases of the vehicle (first part) and on the entire life cycle, including the use phase (second part). The largest share of GHG emissions for the hydrogen-powered truck (first part) originates from the tank system and the chassis, specifically due to the materials reinforced plastics, steel, and aluminum. The fuel cell system is responsible for half of the MRS, mainly due to the used platinum, which, as well as steel, accounts for about one-third of the MRS. The hydrogen supply path is the most crucial factor determining the overall GHG emissions (second part). To reduce GHG emissions compared to a conventional diesel-driven truck, the share of renewable energy within the power mix has to be at least 61 %. The MRS increases with an increasing share of renewable energy within the power mix. To reduce GHG emission of a converted hydrogen-powered truck, the use of reinforced plastics and platinum should be minimized, thus contributing to more efficient use of mineral resources.Publicationtype: Journal Article65 176