TY - INPR A1 - Schumm, Leon A1 - Abdel-Khalek, Hazem A1 - Brown, Tom A1 - Ueckerdt, Falko A1 - Sterner, Michael A1 - Fioriti, Davide A1 - Parzen, Max T1 - The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition N2 - As global demand for green hydrogen rises, potential hydrogen exporters move into the spotlight. However, the large-scale installation of on-grid hydrogen electrolysis for export can have profound impacts on 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-benets of domestic climate change mitigation and hydrogen exports, whereby exports can reduce domestic electricity prices while mitigation reduces hydrogen export prices. However, increasing hydrogen exports quickly in a system that is still dominated by fossil fuels can substantially raise domestic electricity prices, if green hydrogen production is not regulated. Surprisingly, temporal matching of hydrogen production lowers domestic electricity cost by up to 31% while the effect on exporters is minimal. 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. KW - Energy Transition KW - Hydrogen regulation KW - Hydrogen export KW - Climate-neutral KW - Domestic prices KW - Hydrogen prices KW - Power-to-X Y1 - 2024 U6 - https://doi.org/10.21203/rs.3.rs-4285425/v1 N1 - Der Aufsatz wurde peer-reviewed veröffentlicht und ist ebenfalls in diesem Repositorium verzeichnet unter: https://opus4.kobv.de/opus4-oth-regensburg/8485 PB - Research Square Platform LLC ER - TY - JOUR A1 - Schumm, Leon A1 - Brown, Tom A1 - Abdel-Khalek, Hazem A1 - Ueckerdt, Falko A1 - Sterner, Michael A1 - Fioriti, David A1 - Parzen, Max T1 - The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition JF - Nature Communications N2 - 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. KW - Energy Transition KW - Hydrogen regulation Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-84857 N1 - Die Preprint-Version ist ebenfalls in diesem Repositorium verzeichnet unter: https://opus4.kobv.de/opus4-oth-regensburg/7272 VL - 16 PB - Nature CY - London ER - TY - CHAP A1 - Schamel, Marco A1 - Achhammer, Anton A1 - Schumm, Leon A1 - Sterner, Michael T1 - Harvesting Sustainability: Cost-competitiveness of Green Fertilizer Value Chains in Western Africa T2 - Proceedings of the 2025 IEEE PES/IAS PowerAfrica Conference (PAC 2025): pioneering sustainable energy solutions for Africa's Future, 28.09-02.10 2025, Cairo, Egypt N2 - The use of nitrogen fertilizers in Sub-Saharan Africa is low compared to other regions of the world, leading to inadequate crop yields. Furthermore, conventional production from fossil fuel-based ammonia is highly emissions-intensive, making decarbonization urgent. Local production using green hydrogen, sourced solely from solar energy, water, and air, could address both agricultural and climate challenges. This study focuses on Ghana, where nitrogen inputs are among the lowest globally. Using an open-source framework, we evaluate high-resolution production costs for sustainable ammonia and examine two decarbonized pathways: aqueous ammonia and urea. It is found that cost estimates with current assumptions mostly exceed historical prices. However, given their resilience to global market disruptions and expected future cost decreases of the technologies used, these sustainable approaches represent a promising pathway for development in Sub-Saharan Africa. Y1 - 2025 SN - 979-8-3315-9850-1 U6 - https://doi.org/10.1109/PowerAfrica65840.2025.11289137 PB - IEEE ER - TY - JOUR A1 - Schumm, Leon A1 - Haas, Jannik A1 - Peer, Rebecca A1 - Sterner, Michael T1 - The role of hydrogen offtaker regulation in highly renewable electricity systems JF - Energy N2 - The growing demand for green hydrogen necessitates a rapid scale-up of production and exports to meet decarbonization targets globally. However, current ramp-up efforts remain insufficient, calling for policies that unlock the potential of hydrogen as a low-carbon energy carrier. A key lever is the offtaker regulation, which impacts the pace and sustainability of export projects. This study investigates minimum renewable share requirements for hydrogen exports in countries with high renewable electricity shares. Using New Zealand as a case study, we develop a fully sector-coupled capacity expansion and dispatch model, integrating hydrogen and electricity network planning based on PyPSA-Earth. The model optimizes New Zealand’s energy system under varying export scenarios, renewable electricity shares, and resulting system impacts. We find that domestic electricity demand and renewable expansion rates dominate long-term outcomes, while progressive regulation enables short-term hydrogen and Power-to-X exports. Relaxing the renewable threshold from 80% to 60% triples export volumes from 2.5 TWh to 8.2 TWh by 2030. We propose a two-stage requirement: an initially progressive threshold to attract investment with low consequential emissions, followed by stricter regulation to prevent high emissions, rising domestic electricity prices, and declining hydrogen competitiveness. This framework, demonstrated for New Zealand, can guide hydrogen-exporting countries worldwide. KW - Climate neutrality KW - e-fuels KW - Emission intensity KW - Energy systems modelling KW - Hydrogen exports KW - Hydrogen offtaker regulation KW - Power-to-X Y1 - 2026 U6 - https://doi.org/10.1016/j.energy.2025.139513 N1 - Corresponding author der OTH Regensburg: Leon Schumm VL - 342 PB - Elsevier ER - TY - GEN A1 - Rahim, Stefan A1 - Schumm, Leon T1 - Weather Data Cutouts for the Wasserstoffatlas (Hydrogen Map) [Data set] N2 - The cutouts are required to calculate the solar PV and wind onshore feed-in profiles of the Wasserstoffatlas. The provided cutouts are spatiotemporal subsets of the European weather data from the ECMWF ERA5 reanalysis dataset and the CMSAF SARAH-2 solar surface radiation dataset for the year 2013. They have been prepared by and are for use with the atlite tool (https://atlite.readthedocs.io/). ECMWF ERA5 Source: https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=overview Terms of Use: https://cds.climate.copernicus.eu/api/v2/terms/static/20180314_Copernicus_License_V1.1.pdf CMSAF SARAH-2 Pfeifroth, Uwe; Kothe, Steffen; Müller, Richard; Trentmann, Jörg; Hollmann, Rainer; Fuchs, Petra; Werscheck, Martin (2017): Surface Radiation Data Set - Heliosat (SARAH) - Edition 2, Satellite Application Facility on Climate Monitoring, DOI:10.5676/EUM_SAF_CM/SARAH/V002, https://doi.org/10.5676/EUM_SAF_CM/SARAH/V002 Terms of Use: https://www.eumetsat.int/cs/idcplg?IdcService=GET_FILE&dDocName=pdf_leg_data_policy&allowInterrupt=1&noSaveAs=1&RevisionSelectionMethod=LatestReleased Y1 - 2023 U6 - https://doi.org/10.5281/zenodo.8135586 ER - TY - GEN A1 - Birett, Falk A1 - Schumm, Leon A1 - Hofrichter, Andreas A1 - Heusgen, Valentin A1 - Rahim, Stefan T1 - Wasserstoffatlas Deutschland (Hydrogen Map) [Data set] N2 - Input files required for Hydrogen Map workflow in the project "Wasserstoffatlas Deutschland", funded by the BMBF. Y1 - 2025 U6 - https://doi.org/10.5281/zenodo.13960465 N1 - Further versions linked on Zenodo. ER - TY - CHAP A1 - Hinterreiter, Marion A1 - Brückl, Oliver A1 - Rauch, Johannes ED - Schulz, Detlef T1 - Methodology for long-term reactive power forecasts of medium-voltage grids T2 - NEIS 2025 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 15 – 16, 2025 N2 - 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. KW - reactive power KW - forecasting KW - long-term KW - medium-voltage level KW - grid level interaction Y1 - 2025 SN - 978-3-8007-6633-8 SP - 218 EP - 223 PB - VDE Verlag ER - TY - CHAP A1 - Stadler, Andreas A1 - Kraus, Hermann A1 - Brückl, Oliver ED - Technische Universität München, T1 - Proposing an Optimization Model for a techno-economic Evaluation of Energy Storage Systems T2 - PESS 2025 – IEEE Power and Energy Student Summit, October 08 – 10, 2025 in Munich, Germany N2 - 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. KW - energy storage systems KW - techno economic evaluation KW - electricity trading KW - optimization KW - ess profitability Y1 - 2025 SN - 978-3-8007-6656-7 SP - 97 EP - 102 PB - VDE ER - TY - CHAP A1 - Hinterreiter, Marion A1 - Brückl, Oliver A1 - Rauch, Johannes ED - Technische Universität München, T1 - Challenges and Approaches for Long-Term Reactive Power Forecasting in Power Systems T2 - PESS 2025 – IEEE Power and Energy Student Summit, October 08 – 10, 2025 in Munich, Germany N2 - 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. KW - reactive power KW - forecasting KW - long-term KW - network models Y1 - 2025 SN - 978-3-8007-6656-7 SP - 109 EP - 114 PB - VDE Verlag ER - TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver A1 - Engel, Bernd ED - Schulz, Detlef, T1 - Optimal Reactive Power Planning by covering deficient voltage demands with additional reactive power sources using a sensitivity approach T2 - NEIS 2023 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 4 – 5, 2023 N2 - The determination of the optimal location, types and size of additional required reactive power sources is a main interest of Reactive Power Planning (RPP) investigations and of this paper. The planning problem addresses the maintenance of voltage stability, which is an ancillary service in Germany, and can be formulated as a mixed-integer optimization prob-lem. The aim of this work is a techno-economically efficient coverage of the deficient steady state voltage deviation demands (VDD) by placing new reactive power sources with adequate size or extending the reactive power potential of existing sources. An optimization model is set up to solve the planning problem by using load flow voltage sensitivities, which quantify and evaluate the technical efficiency of new reactive power sources in relation to the present voltage deviation demands. Operating and investment costs are used as economic decision parameters. Within an application example, which is carried out with an exemplary transmission system, the solution of the planning problem is discussed. KW - reactive power planning KW - voltage control KW - optimal power flow KW - sensitivity analysis KW - system planning Y1 - 2023 UR - https://ieeexplore.ieee.org/document/10556672 SN - 978-3-8007-6134-0 SP - 223 EP - 230 PB - VDE Verlag CY - Berlin ER - TY - THES A1 - Thema, Martin Jiří T1 - Process optimization for microbial biosynthesis of methane in a trickle-bed reactor for Power-to-Gas applications: the ORBIT-process N2 - This thesis identifes Power-to-Gas in general and biological CO2-methanation in trickle-bed reactors in particular as promising energy storage and sector coupling technology ready for application but with further optimization potential. It reviews the global status and development of Power-to-Gas technology as to be of exponentially growing importance in energy systems changing towards renewable power supply and analyzes optimization and standardization potential for biological CO2-methanation in tricklebed reactors deriving an improved methanation process. Process development and experiments on hydrodynamical and biological improvement of such a setup were performed, leading to an optimized combination of a packing and microorganisms in pure culture embedded in the new ORBIT-process. First experimental results give evidence of successful application of different optimization approaches implemented in a technical center scale setup. N2 - Die vorliegende Arbeit analysiert Status und Entwicklung der Power-to-Gas-Technologien Wasserelektrolyse und CO2-Methanisierung hinsichtlich Kosten, technischer Parameter und energiepolitischer Stellung in den wichtigsten Einsatzländern. So konnte ein exponentieller Trend in zugebauter Anlagenleistung sowie deutliche Investitionskostendegressionen für alle untersuchten Technologien abgeleitet werden. Die Arbeit entwickelt Optimierungs- und Standardisierungsansätze für die biologische CO2-Methanisierung im Rieselbett-Reaktor, welche als eine der vielversprechenden Power-to-Gas-Anwendungen identifiziert wird. Mit Versuchen zur Verbesserung der hydrodynamischen Bedingungen im Reaktor sowie zu einer optimierten Verbindung aus Packungselementen und Mikroorganismen in Reinkultur wird daraus der neue ORBIT-Prozess abgeleitet. Erste Versuchsergebnisse aus einer realisierten Anlage im Technikumsmaßstab deuten hin auf die erfolgreiche Umsetzung der identifzierten Optimierungsansätze. T2 - Prozessoptimierung zur biologischen CO2-Methanisierung im Rieselbettreaktor f¨ur Power-to Gas-Anwendungen: der ORBIT-Prozess KW - CO2-methanation KW - ORBIT-process KW - Power-to-Gas KW - biological methanation KW - biomethanation KW - trickle-bed reactor Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?https://nbn-resolving.org/urn:nbn:de:bvb:29-opus4-150567 SN - 978-3-8440-7656-1 ER - TY - CHAP A1 - Sterner, Michael ED - Faulstich, Martin ED - Mocker, Mario T1 - WBGU Gutachten - zukunftsfähige Bioenergie und nachhaltige Landnutzung T2 - Biomasse & Abfall : Emissionen mindern und Rückstände nutzen (Verfahren & Werkstoffe für die Energietechnik ; 5) Y1 - 2009 SN - 9783981039146 SP - 23 EP - 28 PB - Dorner Printconcept CY - Sulzbach-Rosenberg ER - TY - INPR A1 - Achhammer, Anton A1 - Fioriti, Davide A1 - Patonia, Aliaksei A1 - Sterner, Michael T1 - The impact of hydrogen underground storage on fair partnerships: a GIS-based integration of salt caverns into PyPSA-Earth N2 - The increasing demand for hydrogen in Europe and the development of cross-border infrastructure, such as the SoutH2 Corridorconnecting Tunisia, Italy, Austria, and Germany, underscore the importance for hydrogen storage solutions to ensure supplysecurity and competitive pricing. Without storage, producers face increased market dependency, as electrolyzers require con-tinuous operation to remain economically viable. At the same time, storage offers opportunities to strengthen domestic valuechains by securing hydrogen supply for local industries. To assess the system-level impact of underground hydrogen storageand its implications for hydrogen partnerships, we integrate GIS-based salt cavern potentials into PyPSA-Earth and apply theframework to Tunisia. Salt caverns are currently largely considered the most economical option for large-scale hydrogen storage,offering operational flexibility. Underground storage is represented as an endogenously optimised, regionally constrained option,enabling a direct comparison between scenarios with and without geological storage under identical demand, technology, andpolicy assumptions.Our results show that underground hydrogen storage enables seasonal balancing at multi-terawatt-hour scale, reshaping hydro-gen system design. Storage availability substitutes most aboveground hydrogen tank capacity, improves electrolyser utilisation,and reduces levelised hydrogen production costs by approximately 0.10 € kg−1. Moreover, it decouples hydrogen production fromshort-term electricity variability and export demand, enhancing supply stability and export competitiveness.Beyond the Tunisian case, the findings underscore the strategic role of geological storage in international hydrogen trade. Byincreasing resilience and reducing cost volatility, underground hydrogen storage strengthens the position of exporting regionsand supports more balanced and sustainable hydrogen partnerships. KW - Energy Transition KW - Hydrogen export KW - hydrogen underground storage KW - Hydrogen prices KW - salt caverns KW - Power-to-X KW - PyPSA-Earth Y1 - 2026 U6 - https://doi.org/10.2139/ssrn.6307406 PB - SSRN ER -