@article{BauerSterner, author = {Bauer, Franz and Sterner, Michael}, title = {Impacts of lifestyle changes on energy demand and greenhouse gas emissions in Germany}, series = {Renewable and Sustainable Energy Reviews}, volume = {207}, journal = {Renewable and Sustainable Energy Reviews}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1364-0321}, doi = {10.1016/j.rser.2024.114944}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-77682}, pages = {17}, abstract = {Most energy scenario studies typically focus on technological options and fuel substitution for decarbonising future energy systems. Lifestyle changes are rarely considered, although they can significantly reduce energy demand and climate change mitigation efforts. By using an energy system model, this study shows that it is possible to reduce final energy demand in Germany by 61 \% in 2050 relative to 2019 levels, resulting in an annual per capita energy demand of 44 GJ for a representative country of the Global North. This goal can be achieved through a combination of technological measures and lifestyle changes without sacrificing a decent standard of living. Societal chances can eliminate reliance on not-yet-established negative emission technologies, reduce energy dependency, and reduce the need for energy-intensive hydrogen and e-fuels. Downsizing the energy system provides an opportunity for strengthening climate change mitigation, decrease material demand and reduce land use.}, language = {en} } @article{MuehlbauerKeinerGerhardsetal., author = {M{\"u}hlbauer, Andreas and Keiner, Dominik and Gerhards, Christoph and Caldera, Upeksha and Sterner, Michael and Breyer, Christian}, title = {Assessment of technologies and economics for carbon dioxide removal from a portfolio perspective}, series = {International Journal of Greenhouse Gas Control}, volume = {141}, journal = {International Journal of Greenhouse Gas Control}, publisher = {Elsevier}, doi = {10.1016/j.ijggc.2024.104297}, pages = {25}, abstract = {Carbon dioxide removal (CDR) is essential to achieve ambitious climate goals limiting global warming to less than 1.5◦C, and likely for achieving the 1.5◦C target. This study addresses the need for diverse CDR portfolios and introduces the LUT-CDR tool, which assesses CDR technology portfolios aligned with hypothetical societal preferences. Six scenarios are described, considering global deployment limitations, techno-economic factors, area requirements, technology readiness, and storage security for various CDR options. The results suggest the feasibility of large-scale CDR, potentially removing 500-1750 GtCO2 by 2100 to meet the set climate targets. For a 1.0◦C climate goal, CDR portfolios necessitate 12.0-37.5\% more primary energy compared to a scenario without CDR. Remarkably, funding a 1.0◦C target requires only 0.42-0.65\% of the projected global gross domestic product. Bioenergy carbon capture and sequestration and rainfall-based afforestation play limited roles, while secure sequestration of captured CO2 via direct air capture, electricity-based carbon sequestration, and desalination-based afforestation emerge as more promising options. The study offers crucial techno-economic parameters for implementing CDR options in future energy-industry-CDR system analyses and demonstrates the tool's flexibility through alternative assumptions. It also discusses limitations, sensitivities, potential tradeoffs, and outlines options for future research in the area of large-scale CDR.}, language = {en} } @article{KeinerWalterBogdanovetal., author = {Keiner, Dominik and Walter, Lukas and Bogdanov, Dmitrii and Peters, Ian Marius and Breyer, Christian}, title = {Assessing the impact of bifacial solar photovoltaics on future power systems based on capacity-density-optimised power plant yield modelling}, series = {Solar Energy}, volume = {295}, journal = {Solar Energy}, publisher = {Elsevier}, doi = {10.1016/j.solener.2025.113543}, pages = {35}, abstract = {Bifacial solar photovoltaic (PV) technology is currently taking over the solar PV module market, exceeding a 90\% share in 2025. This important technology must be included in energy system modelling. This study provides a method for calculating the yield of monofacial and bifacial power plants in fixed-tilted, single-axis tracking, and east-west facing vertical setup. A novel method is introduced to maximise the capacity density of solar PV power plants without the need for detailed land cost for the most efficient use of the occupied area. The results indicate a 15-20\% yield gain from single-axis tracking compared to fixed-tilted power plants, and a limited bifacial gain of up to 10\% for most areas of the world. Higher bifacial gains are sporadically possible in specific conditions. Fixed-tilted systems show higher bifacial gains. Optimising tilt angles and row pitch would allow for 147 MW/ km2 capacity density today, though on average 70-110 MW/km2 can be achieved for 20.2\% module efficiency. The impact on the power system, studied in a free cost optimisation scenario and forcing vertical bifacial PV scenario, implying agrivoltaics, is not significant with a +/- 10\% change in total solar PV capacity, change in installed wind power of on average-10\%, increase of installed battery capacity of on average 5\%, and an on average changed levelised cost of electricity of-2\% globally. Bifacial solar PV technology has been found to be beneficial but no game changer for future power systems; system improvements are widely possible underlining the important role of this technology.}, language = {en} } @article{DoepfertCandasKrausetal., author = {Doepfert, Markus and Candas, Soner and Kraus, Hermann and Tzscheutschler, Peter and Hamacher, Thomas}, title = {Assessing the techno-economic benefits of LEMs for different grid topologies and prosumer shares}, series = {iScience}, volume = {28}, journal = {iScience}, number = {6}, publisher = {Elsevier - Cell Press}, doi = {10.1016/j.isci.2025.112493}, abstract = {The shift toward decentralized and renewable energy sources has introduced significant challenges to traditional power systems, necessitating innovative market designs. Local energy markets present a viable solution for integrating distributed energy resources such as photovoltaic systems, electric vehicles, and heat pumps. This study investigates the techno-economic implications of local energy markets compared to conventional market designs, focusing on their impact on average energy prices and operational peak power. Through comprehensive simulations across various grid topologies with varying penetration levels of the distributed energy resources, totaling 400 simulation setups, we demonstrate that local energy markets can enhance economic efficiency and grid stability with 99\% of the scenarios boasting lower average energy prices and 80\% lower operational peak power levels. The findings suggest that local energy markets can play a role in the future energy system, provided that additional infrastructure, management costs, and bureaucratic complexity are kept to a minimum.}, language = {en} } @article{DahmenBogenbergerWeikl, author = {Dahmen, Victoria and Bogenberger, Klaus and Weikl, Simone}, title = {Modellierung des Verkehrsmittelwahlverhaltens mittels erkl{\"a}rbarem Maschinellem Lernen}, series = {Straßenverkehrstechnik}, volume = {69}, journal = {Straßenverkehrstechnik}, number = {2}, publisher = {Kirschbaum}, issn = {0039-2219}, doi = {10.53184/SVT2-2025-3}, pages = {96 -- 102}, abstract = {Die Modellierung der Verkehrsmittelwahl ist f{\"u}r die Vorhersage und das Verst{\"a}ndnis des Mobilit{\"a}tsverhaltens unerl{\"a}sslich. Hierbei wurden in den letzten Jahren mit maschinellem Lernen vielversprechende Ergebnisse erzielt, insbesondere f{\"u}r XGBoost- und Random-Forest-Modelle. Aufgrund der zunehmenden Verwendung von Tracking-basierten Smartphone-Apps zur Aufzeichnung des Mobilit{\"a}tsverhaltens, wenden wir diese Modelle auf einen solchen Datensatz an. Zudem analysieren wir eingehend deren Interpretierbarkeit. Wir kommen zu dem Schluss, dass das XGBoost-Modell am leistungsst{\"a}rksten und dennoch erkl{\"a}rbar ist. Die von solchen Modellen gewonnenen Erkenntnisse k{\"o}nnen beispielsweise genutzt werden, um die Verkehrsmittelwahl f{\"u}r beliebige Quelle-Ziel-Paare vorherzusagen.}, language = {de} } @inproceedings{ReichelGerstnerSchilleretal., author = {Reichel, Tobias and Gerstner, Mathias and Schiller, Leo and Attenberger, Andreas and Hackenberg, Rudolf and Dološ, Klara}, title = {A forensic analysis of GNSS spoofing attacks on autonomous vehicles}, series = {Cloud Computing 2025 : The Sixteenth International Conference on Cloud Computing, GRIDs, and Virtualization, 06.-10. April 2025, Valencia}, booktitle = {Cloud Computing 2025 : The Sixteenth International Conference on Cloud Computing, GRIDs, and Virtualization, 06.-10. April 2025, Valencia}, organization = {IARIA}, isbn = {978-1-68558-258-6}, issn = {2308-4294}, pages = {32 -- 39}, abstract = {Global Navigation Satellite Systems (GNSSs) are essential for modern technology, enabling precise geographic positioning in aviation, maritime shipping, and automotive systems. In the future, their role will be even more critical for autonomous vehicles, which rely on accurate localization for navigation and decision-making. However, the increasing connectivity of autonomous vehicles exposes them to cyber threats, including GNSS spoofing attacks, which manipulate location data to mislead onboard systems. As reliance on GNSS grows, so does the risk posed by spoofing attacks, making it a critical security concern. This paper describes GNSS spoofing attacks on autonomous vehicles, focusing on their detection both during and after an attack. Furthermore, we analyze data storage strategies to facilitate effective forensic analysis. We highlight the importance of position, signal, and camera data, which should be preserved to ensure a comprehensive forensic investigation. Finally, we suggest a simulation setup that enables studying which data could be used for a forensic investigation. Additionally, we examine established data frameworks and decide whether they are suitable for detecting GNSS spoofing attacks.}, language = {en} } @techreport{BergmeierBockFischeretal., author = {Bergmeier, Sonja and Bock, Maximilian and Fischer, Lukas and Flassig, Nathanael and Hidv{\´e}gi, Barnab{\´a}s and B{\"a}cher, Tim and Hierl, Jonas and Kaltenbach, Dominik and Lackermeier, Florian and Laubmann, Julia and Liebl, Jonas and Pirthauer, Tobias and Reif, Robin and Roider, Stefan}, title = {FMS-Berichte Wintersemester 2024/25}, series = {FMS-Berichte Wintersemester 2024/25}, volume = {2024}, journal = {FMS-Berichte Wintersemester 2024/25}, number = {9}, editor = {Fuhrmann, Thomas and Hipp, Susanne and Niemetz, Michael and Sterz, Oliver}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg / Fakult{\"a}t Elektro- und Informationstechnik}, doi = {10.35096/othr/pub-8312}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-83121}, pages = {76}, abstract = {Dieser Bericht entstand urspr{\"u}nglich auf Initiative der Studierenden des damals neuen Masterstudiengangs „Elektro- und Informationstechnik (MEI)" an der OTH Regensburg, die an der Pflichtlehrveranstaltung „Forschungsmethoden und Seminar (FMS)" im Wintersemester 2020/21 teilnahmen. Diese Lehrveranstaltung hat das Ziel, systematisch an das wissenschaftliche Arbeiten, speziell die Wissenschaftskommunikation, heranzuf{\"u}hren. Daher ist im Laufe der Veranstaltung geeignete Literatur zu einem individuellen Thema zu recherchieren, sind Ver{\"o}ffentlichungen auf ihre Relevanz hin zu beurteilen und letztendlich gilt es eine eigene Ausarbeitung basierend auf der Literaturrecherche zu erstellen und diese in einem Vortrag zu pr{\"a}sentieren. Parallel dazu wird im Theorieteil die entsprechende Hinf{\"u}hrung zu den verschiedenen Elementen der Wissenschaftskommunikation vermittelt: • Bedeutung der Wissenschaftskommunikation f{\"u}r die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualit{\"a}t aufgefundener Fachliteratur, Auswahl geeigneter Materialien f{\"u}r die eigene Arbeit • Aufbereitung und Darstellung der recherchierten technischer Inhalte in Form einer seitenanzahlbegrenzten wissenschaftlichen Ausarbeitung • Einhalten formaler Randbedingungen bzgl. Strukturierung, einschl. Bildnachweise und Zitationsstile • Peer-review-Prozess bei wertsch{\"a}tzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschul{\"o}ffentlicher Pr{\"a}sentation der Ergebnisse • F{\"u}hren m{\"u}ndlicher wissenschaftlicher Diskurse Die pr{\"a}sentierten Themen beruhen nicht auf eigener Forschungst{\"a}tigkeit, sondern sind als einf{\"u}hrende Reviewartikel zum jeweiligen vorgegebenen technischen oder gesellschaftspolitischen Forschungsthema zu verstehen.}, subject = {Elektrotechnik}, language = {mul} } @unpublished{MeisingerHofrichterBaueretal., author = {Meisinger, Alexander and Hofrichter, Andreas and Bauer, Franz and Sterner, Michael}, title = {Unlocking Potential Energy Partnerships in Europe: a Case Study on the Way to a Franco-German Energy Transition}, publisher = {SSRN}, doi = {10.2139/ssrn.5251699}, pages = {23}, abstract = {Global warming is already causing global destabilization. Geopolitical challenges fuel this instability and highlight the need for trusted energy partnerships to ensure energy security. To limit global warming and increase energy security, it is essential to take joint action on an international and global scale. The European Green Deal contributes to this. However, specific national actions are still needed. This research presents a way forward for a Franco-German energy transition and unlocks the potential of energy partnerships within Europe, using a cost-based, sector-coupled optimization model. Both countries are coupled via an isolated country optimization approach. Thus, the focus is on the development of each national energy system. The results highlight the increase of energy security in line with the European Green Deal. The main pillars of the energy transition are solar energy (32- 33\%), wind energy (25-38\%) and biogenic energy sources (13-27\%). Nuclear power is being phased out in Germany and France. The results show that a Franco-German energy partnership has great potential. Overall, France can cost-effectively cover 25\% of Germany's hydrogen import needs (122 TWh) in 2050. At the same time, France can also benefit from the energy partnership in terms of economic growth and joint action to mitigate climate crisis.}, language = {en} } @techreport{VolkenhoffGerstenbergerBreitbarthetal., author = {Volkenhoff, Tobias and Gerstenberger, Marcus and Breitbarth, Lutz and Carstensen, Christian and D{\"o}lger, Reiner and Feldges, Michael and Hegewald, Jessica and Mutzbauer, Johannes and Rose, Martin and Schopf, Hans J{\"u}rgen and Schroth, Max and Schwietering, Christoph and Seidel, Christian and Sievers, Ariane and Spangler, Matthias and Trupat, Stefan and {\"U}st{\"u}n, Ellen}, title = {H NBA - Hinweise zum Einsatz von Netzbeeinflussungsanlagen}, number = {310/1}, edition = {Ausgabe 2025}, publisher = {FGSV}, address = {K{\"o}ln}, isbn = {978-3-86646-434-8}, pages = {94}, language = {de} } @article{SchummBrownAbdelKhaleketal., author = {Schumm, Leon and Brown, Tom and Abdel-Khalek, Hazem and Ueckerdt, Falko and Sterner, Michael and Fioriti, David and Parzen, Max}, title = {The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition}, series = {Nature Communications}, volume = {16}, journal = {Nature Communications}, publisher = {Nature}, address = {London}, doi = {10.1038/s41467-025-62873-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-84857}, pages = {13}, abstract = {As global demand for green hydrogen rises, potential hydrogen exporters move into the spotlight. While exports can bring countries revenue, large-scale on-grid hydrogen electrolysis for export can profoundly impact domestic energy prices and energy-related emissions. Our investigation explores the interplay of hydrogen exports, domestic energy transition and temporal hydrogen regulation, employing a sector-coupled energy model in Morocco. We find substantial co-benefits of domestic carbon dioxide mitigation and hydrogen exports, whereby exports can reduce market-based costs for domestic electricity consumers while mitigation reduces costs for hydrogen exporters. However, increasing hydrogen exports in a fossil-dominated system can substantially raise market-based costs for domestic electricity consumers, but surprisingly, temporal matching of hydrogen production can lower these costs by up to 31\% with minimal impact on exporters. Here, we show that this policy instrument can steer the welfare (re-)distribution between hydrogen exporting firms, hydrogen importers, and domestic electricity consumers and hereby increases acceptance among actors.}, language = {en} } @techreport{BhardwajHauerMueckeetal., type = {Working Paper}, author = {Bhardwaj, Prakhar and Hauer, Franziska and M{\"u}cke, Vanessa and Dotter, Caroline and Haug, Sonja and Weikl, Simone and Weber, Karsten}, title = {Recording and understanding multi- and intermodal mobility - a review}, address = {Regensburg}, doi = {10.35096/othr/pub-8742}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-87427}, pages = {25}, abstract = {The transition to sustainable mobility requires detailed knowledge of actual mobility behavior. Recording mobility behavior through conventional, aggregated, or retrospective survey methods (e.g., counting stations, travel diaries) may yield incomplete insights. In addition, these methods are often expensive, prone to error, or not scalable. The aim of this literature review is to provide a systematic overview of the current state of the literature on recording and analysis of individual mobility data and, based on this, to identify possible research gaps and potential. The exploratory literature review includes social science surveys on multi- and intermodal mobility behavior, as well as an overview of possible ways to analyze travel data. The focus of the latter is on identifying relevant data sources and methodological approaches for segmentation, identification of transport mode, and trip purpose determination. Results from recent studies show that sensor-based data collection alone is not sufficient to fully and accurately map mobility behavior. One possible solution is a "best-of-both-worlds" approach that combines passive, automatic mobility data collection via smartphone sensors with targeted user corrections and additions ("human-in-the-loop") within an app. The literature review shows that this approach yields the best data quality. Combining mobility surveys with passive collection of mobility data provides a comprehensive, accurate, and complete overview of mobility behavior.}, language = {en} } @misc{BirettSchummHofrichteretal., author = {Birett, Falk and Schumm, Leon and Hofrichter, Andreas and Heusgen, Valentin and Rahim, Stefan}, title = {Wasserstoffatlas Deutschland (Hydrogen Map) [Data set]}, doi = {10.5281/zenodo.13960465}, abstract = {Input files required for Hydrogen Map workflow in the project "Wasserstoffatlas Deutschland", funded by the BMBF.}, language = {en} } @inproceedings{HinterreiterBruecklRauch, author = {Hinterreiter, Marion and Br{\"u}ckl, Oliver and Rauch, Johannes}, title = {Methodology for long-term reactive power forecasts of medium-voltage grids}, series = {NEIS 2025 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 15 - 16, 2025}, booktitle = {NEIS 2025 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 15 - 16, 2025}, editor = {Schulz, Detlef}, publisher = {VDE Verlag}, isbn = {978-3-8007-6633-8}, pages = {218 -- 223}, abstract = {Understanding and assessing the long-term behavior of reactive power is crucial for power system planning and invest-ment decisions. This is particularly growing relevant for the lower voltage-grid levels, which are gaining importance due to significant changes in grid behavior, operational strategies, energy generation and consumption patterns. Currently, standardized methodologies for forecasting reactive power in medium-voltage grids are lacking, creating a gap in research and practical applications. To optimize grid investments and expansions, informed decisions based on reliable research and accurate forecasts are essential. This paper presents a methodology for long-term reactive power forecasting in me-dium-voltage grids, introducing a new approach to account for low- and medium-voltage grid interactions while address-ing common challenges like limited available grid data and scenario framework definition. The aim of the forecast is the future reactive power behaviour of a medium-voltage-grid at the high-voltage side of the high-voltage to medium-voltage transformer. The medium-voltage-level is modelled using a grid model approach, while low-voltage grids are being mod-elled using generic distribution grids. A 209-bus medium-voltage-grid model is used as an application example and to provide two exemplary use cases for a reactive power forecast for 2045.}, language = {en} } @inproceedings{StadlerKrausBrueckl, author = {Stadler, Andreas and Kraus, Hermann and Br{\"u}ckl, Oliver}, title = {Proposing an Optimization Model for a techno-economic Evaluation of Energy Storage Systems}, series = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, booktitle = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, editor = {Technische Universit{\"a}t M{\"u}nchen,}, publisher = {VDE}, isbn = {978-3-8007-6656-7}, pages = {97 -- 102}, abstract = {During the global energy crisis in 2022, electricity prices increased drastically. This lead, together with an overall higher price volatility to possibly higher electrical energy storage system (ESS) profitability. To test if the investment in an ESS can now be more profitable, an approach for a techno-economic evaluation of ESS is presented in this paper, using an optimization algorithm to determine the optimal way of covering a load flow profile with electricity trading products on the electricity market with and without the use of an energy storage system. The cost differences between using or not using the storage system are assumed to be the profits of the ESS, which must exceed the (interest-bearing) investment costs over its lifetime. The correct way of operation of the optimization model is validated and several storage sizes and capacities as well as several years of the electricity market data was analyzed, once with a perfect forecast of all prices of the electricity trading products and once with a forecast based on the previous years purchasing strategy. The results show that, using the prognosis and a 2 \% p.a. interest rate, only the storage combinations for 2.5 MWh/ 2.5 MW and 1 MWh/ 1 MW show profitability in 2023, whereas 2017 and 2020 show no profitability.}, language = {en} } @inproceedings{HinterreiterBruecklRauch, author = {Hinterreiter, Marion and Br{\"u}ckl, Oliver and Rauch, Johannes}, title = {Challenges and Approaches for Long-Term Reactive Power Forecasting in Power Systems}, series = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, booktitle = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, editor = {Technische Universit{\"a}t M{\"u}nchen,}, publisher = {VDE Verlag}, isbn = {978-3-8007-6656-7}, pages = {109 -- 114}, abstract = {The transition from fossil fuels to renewable energy sources is driving profound changes across all voltage levels of the electrical grid, altering active power (P) as well as reactive power (Q) behavior. This transformation involves a shift from predominantly top-down, unidirectional electricity flows to bidirectional and increasingly complex flow patterns, fundamentally altering the operation and utilization of power systems. Many countries are already reporting notable changes in their transmission grid Q. This can lead to increased costs for grid expansion and compensation equipment, as well as grid losses. To minimize these losses and ensure grid stability and efficiency, understanding and forecasting Q long-term becomes essential. This paper addresses the challenges of long-term (1-20 years) Q forecasting in general by analyzing Q behavior in grids, the main influencing grid parameters, and reviewing existing forecasting approaches. It evaluates the applicability of these approaches and highlights current research gaps and trends. By focusing on this underexplored area, the paper aims to support the development of more advanced and reliable long-term Q forecasting techniques.}, language = {en} } @article{LambertKrausDoepfertetal., author = {Lambert, Jerry and Kraus, Hermann and Doepfert, Markus and He, Miaomiao and Gschossmann, David and Ceruti, Amedeo and Nemeth, Isabell and Br{\"u}ckl, Oliver and Hamacher, Thomas and Spliethoff, Hartmut}, title = {Assessing the techno-economic impact of district heating on electrical distribution grid reinforcements}, series = {Advances in Applied Energy}, volume = {20}, journal = {Advances in Applied Energy}, publisher = {Elsevier}, issn = {2666-7924}, doi = {10.1016/j.adapen.2025.100251}, pages = {21}, abstract = {Enhanced sector coupling across electricity, mobility, and heating sectors leads to higher efforts for distribution grid upgrades. Based on a case study, this paper evaluates the role of district heating networks in reducing electrical distribution grid reinforcements and compares their economic viability against a building-specific heat supply using heat pumps. A detailed energy system model is used to analyze two building energy renovation scenarios: a business-as-usual scenario with a 1 \% annual renovation rate and an ambitious scenario with a rate of 2 \%. Using a two-step optimization, the impact of different district heating network penetration levels on the distribution grid is evaluated, followed by an ex-post analysis to incorporate a simultaneity factor into district heating networks. Overall, district heating networks can reduce distribution grid reinforcements, but the associated savings alone do not justify their construction, particularly in the ambitious renovation scenario. In the business-as-usual scenario, a district heating network can reduce reinforcement costs by up to 71 \%. However, in the ambitious scenario, grid reinforcements are already reduced due to lower heat peak demand, and the maximal reinforcement cost savings only amount to 35 \%. Compared economically, district heating networks are cost-competitive with building-specific heating only in the business-as-usual scenario, up to a heat supply share of 70 \% and in the ambitious scenario, up to 40 \%. In both scenarios, a district heating network can be a robust solution to lower macroeconomic costs for a carbon-neutral heat supply.}, language = {en} } @misc{RillEiseltKelichhaus, author = {Rill, Georg and Eiselt, Uwe and Kelichhaus, Thomas}, title = {Vehicle dynamics with RecurDyn based on the TMeasy tire model}, series = {26th International Conference on Theoretical and Applied Mechanics (ICTAM), August 25-30, 2024, Daegu, Korea}, journal = {26th International Conference on Theoretical and Applied Mechanics (ICTAM), August 25-30, 2024, Daegu, Korea}, language = {en} } @article{TremmelNaglerKutteretal., author = {Tremmel, Florian and Nagler, Oliver and Kutter, Christoph and Holmer, Rainer}, title = {Double-Beam Cantilever Probe for Crack Probability Analysis of Multilayer Substrates During Wafer Probing}, series = {IEEE Sensors Journal}, volume = {24}, journal = {IEEE Sensors Journal}, number = {24}, publisher = {IEEE}, doi = {10.1109/JSEN.2024.3486355}, pages = {40295 -- 40304}, abstract = {During wafer testing, small probes are contacting pads on the wafer surface to check the chip functionality and identify faulty dies. To prevent damaging structures underneath, a mechanical load limit needs to be defined. This is done by intentionally overstressing the pads and searching for cracks that appear. A customized test bench with a patented sensor-indenter (SI) system is currently used to perform the contact cycles and identify crack formations in real time using the generated acoustic emissions (AEs). This method is faster and more accurate compared with previous optical detection methods. This article presents an improved version of the SI system usable in a wafer prober, featuring a double-beam cantilever beam with an exchangeable indenter tip. This leads to measurement conditions closer to productive wafer testing, enabling more accurate load limit definitions. The cantilever beam contains a strain gauge Wheatstone bridge for contact force measurement and a piezoelectric sensor element for AE signal detection. Amplifier circuits are designed for both sensors, and a data acquisition (DAQ) system is developed. A prototype of the sensor cantilever combination (SCC) is shown together with simulated and experimental results. The accuracy of the force sensor ( ±0.5 → ±1.3 mN) and the signal-to-noise ratios (SNRs) of the AE signals ( 29.1 → 21 dB) show only a small decrease compared with the previous SI system. A crack probability analysis of a test specimen confirms the usability of the SCC, as AE crack signals are detected at a similar mechanical load with both sensor setups.}, language = {en} } @article{SternerHofrichterMeisingeretal., author = {Sterner, Michael and Hofrichter, Andreas and Meisinger, Alexander and Bauer, Franz and Pinkwart, Karsten and Maletzko, Annabelle and Dittmar, Felix and Cremers, Carsten}, title = {19 Import options for green hydrogen and derivatives - An overview of efficiencies and technology readiness levels}, series = {International Journal of Hydrogen Energy}, volume = {90}, journal = {International Journal of Hydrogen Energy}, publisher = {Elsevier}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2024.10.045}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-77756}, pages = {1112 -- 1127}, abstract = {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.}, language = {en} } @article{SalamaKouDawoudetal., author = {Salama, Amgad and Kou, Jisheng and Dawoud, Belal and Simonson, Carey}, title = {A modeling approach for capillary-driven flow of a wetting fluid in a rectangular open microchannel of arbitrary axisymmetric width profile}, series = {International Journal of Thermal Sciences}, volume = {195}, journal = {International Journal of Thermal Sciences}, publisher = {Elsevier}, issn = {1290-0729}, doi = {10.1016/j.ijthermalsci.2023.108622}, pages = {17}, abstract = {Microchips are intensively used in almost all nowadays electronic devices. With the continuous advancement of our technologies, they get smaller in size than ever before. They generate high-intensity heat loads that need to be transported effectively such that they may function properly. Heat pipes have proven to be very effective in transporting relatively large heat loads from miniature components. They are of seamless structure that involves a working fluid capable of evaporation and condensation at the working temperature of the electronic chips. The working fluid is derived to move from the condenser to the evaporator via multiple microgrooves using capillary forces. It is important that the condensate reaches the evaporator at a proper rate such that no dry-out or flooding occur. In this work, we are particularly interested in the case of capillary-driven flows in rectangular microchannels. A generalized model is developed that works for axe-symmetric rectangular channels of arbitrary, moderately varying width profiles. It also accounts for any contrast of viscosity between the liquid and the vapor under isothermal conditions. The model shows to reduce to the special case of imbibition in straight and uniform microchannels, for which comparisons with experimental and modeling works show an excellent match. Cases representing linearly and quadratically varying converging/diverging width profiles have been explored. It is found that the viscosity ratio has a significant influence on the rate at which the meniscus advances. The model also negates the common practice found in the literature of using the formula developed for imbibition rates in capillary tubes for rectangular microchannels by replacing the diameter of the tube with the hydraulic diameter. It is also found that the channel profile has an influential effect on the imbibition rates. For tapered microchannels, the capillary force increases along the channel length while it decreases for diverging ones. It is interestingly demonstrated that, for quadratically tapered microchannel, the speed of the meniscus increases towards the end of the microchannel compared with linearly varying microchannels. On the other hand, for diverging microchannels, the speed of the meniscus decreases due to the increase in the cross-sectional area. Computational fluid dynamics (CFD) analysis has been conducted to provide a framework for confirmation and verification for which very good match has been established, which builds confidence in the modeling approach.}, language = {en} }