Øystein Ulleberg

• Jamma, Mustapha; Bujlo, Piotr & Ulleberg, Øystein (2026). Optimal operation of maritime hybrid fuel cell/battery power systems via a real-time energy management approach – A tugboat case study. Energy Conversion and Management: X. 30. doi: 10.1016/j.ecmx.2026.101780. Full text in Research Archive
• Fordham, David; Llamas-Jansa, Isabel & Ulleberg, Øystein (2025). The cost of simplification: Comparing surrogate electrolyser models in a MILP framework. Energy Conversion and Management: X. 29. doi: 10.1016/j.ecmx.2025.101433. Full text in Research Archive Show summary

  In this work, we investigate how various surrogate models representing an electrolyser’s production curve influence mixed-integer linear programming (MILP) optimisation outcomes. We compare linear, piecewise-linear, and scalable piecewise-linear models, each fitted to a physical electrolyser model, and analyse their effects on hydrogen production overestimation and real revenue in a solar farm/electrolyser array case study. Additionally, we employ a MILP implementation of a rectified linear unit (ReLU) neural network as a surrogate model. The results indicate that using simple linear models can significantly overestimate hydrogen production due to their inability to capture the non-linearity of the component’s efficiency. This overestimation correlates with reduced real revenues. In contrast, the adoption of simple piecewise models can boost returns by up to 14% in this scenario. The findings indicate that simple enhancements to the detail of component models can substantially improve system-level performance and yield more reliable results, without greatly increasing computational demands. While electrolysers were used as a case study, this analysis can be extrapolated and applied to additional components for which surrogate models are required in order to be included in larger energy system models.

• Møller, Amalie Bisgaard; Holm, Thomas; Lie, Bernt; Ulleberg, Øystein; Llamas-Jansa, Isabel & Mirlekar, Gaurav (2025). Modeling the Dynamics of the Proton Exchange Membrane Water Electrolyzer Pressure. IFAC-PapersOnLine. ISSN 2405-8971. 59(29), p. 84–89. doi: 10.1016/j.ifacol.2025.12.186. Full text in Research Archive Show summary

  To simulate the startup, shutdown, standby, and variable operation of Proton Exchange Membrane Water Electrolyzer (PEMWE) systems, it is necessary to model the dynamics of the operating pressure on the hydrogen side (cathode). A simple mathematical model of the cathode pressure has been developed, parametrized, and validated against dynamic high pressure data from the operation of a small-scale PEMWE system laboratory at the Institute for Energy Technology (IFE). The developed model described the actual system dynamics at different current inputs and pressure setpoints. Various equations of state (EoS) for hydrogen gas were compared and the results suggested that hydrogen should be modeled as a real gas at high pressure. The methodology presented in this work is applicable to other PEMWE systems, and the procedure for model parametrization is described in detail.

• Jamma, Mustapha; Bujlo, Piotr & Ulleberg, Øystein (2025). Intelligent Energy Management System for Hybrid Fuel Cell/Battery Powered Ships. IEEE transactions on industry applications. ISSN 0093-9994. 61(6), p. 8283–8296. doi: 10.1109/TIA.2025.3571358. Full text in Research Archive
• Hancke, Ragnhild; Bujlo, Piotr; Holm, Thomas & Ulleberg, Øystein (2024). High-pressure PEM water electrolyser performance up to 180 bar differential pressure. Journal of Power Sources. ISSN 0378-7753. 601. doi: 10.1016/j.jpowsour.2024.234271. Full text in Research Archive
• Egeland-Eriksen, Torbjørn; Jensen, Jonas Flatgård; Ulleberg, Øystein & Sartori, Sabrina (2023). Simulating offshore hydrogen production via PEM electrolysis using real power production data from a 2.3 MW floating offshore wind turbine. International Journal of Hydrogen Energy. ISSN 0360-3199. 48(74), p. 28712–28732. doi: 10.1016/j.ijhydene.2023.03.471. Full text in Research Archive Show summary

  This work presents simulation results from a system where offshore wind power is used to produce hydrogen via electrolysis. Real-world data from a 2.3 MW floating offshore wind turbine and electricity price data from Nord Pool were used as input to a novel electrolyzer model. Data from five 31-day periods were combined with six system designs, and hydrogen production, system efficiency, and production cost were estimated. A comparison of the overall system performance shows that the hydrogen production and cost can vary by up to a factor of three between the cases. This illustrates the uncertainty related to the hydrogen production and profitability of these systems. The highest hydrogen production achieved in a 31-day period was 17 242 kg using a 1.852 MW electrolyzer (i.e., utilization factor of approximately 68%), the lowest hydrogen production cost was 4.53 $/kg H2, and the system efficiency was in the range 56.1–56.9% in all cases.

• Kesana, Netaji Ravikiran; Welahettige, Prasanna; Hansen, Per Morten; Ulleberg, Øystein & Vågsæther, Knut (2023). Modelling of fast fueling of pressurized hydrogen tanks for maritime applications. International Journal of Hydrogen Energy. ISSN 0360-3199. 48(79), p. 30804–30817. doi: 10.1016/j.ijhydene.2023.04.142. Full text in Research Archive Show summary

  This paper studies fast fueling of gaseous hydrogen into large hydrogen (H2) tanks suitable for maritime applications. Three modeling methods have been developed and evaluated: (1) Two-dimensional computational fluid dynamic (CFD) modeling, (2) One-dimensional wall discretized modeling, and (3) Zero-dimensional modeling. A detailed 2D CFD simulation of a small H2-tank was performed and validated with data from literature and then used to simulate a large H2-tank. Results from the 2D-model show non-uniform temperature distribution inside the large tank, but not in the small H2-tank. The 1D-model can predict the mean temperature in small H2-tanks, but not the inhomogeneous temperature field in large H2-tanks. The 0D-model is suitable as a screening tool to obtain rough estimates. Results from the modeling of the large H2-tank show that the heat transfer to the wall during fast filling is inhibited by heat conduction in the wall which leads to an unacceptably high mean hydrogen temperature.

• Fortin, Patrick; Gerhardt, Michael Robert; Ulleberg, Øystein; Zenith, Federico & Holm, Thomas (2022). Multi-Sine EIS for Early Detection of PEMFC Failure Modes. Frontiers in Energy Research. 10. doi: 10.3389/fenrg.2022.855985. Full text in Research Archive Show summary

  Electrochemical impedance spectroscopy (EIS) is a powerful technique that can be used to detect small changes in electrochemical systems and subsequently identify the source of the change. While promising, analysis is often non-intuitive and time-consuming, where collection times of a single EIS spectrum can reach several minutes. To circumvent the long collection times associated with traditional EIS measurements, a multi-sine EIS technique was proposed in which the simultaneous application of many frequencies can reduce the acquisition time to less than a minute. This shortened acquisition time opens the possibility to use multi-sine EIS as a real-time diagnostic tool for monitoring the state-of-health of commercial fuel cell systems. In this work, a single-cell proton exchange membrane fuel cell (PEMFC) was characterised using multi-sine EIS, by establishing steady-state impedance response under baseline conditions before systematically changing operating conditions and monitoring the dynamic changes of the impedance response. Our initial results demonstrate that full multi-sine EIS spectra, encompassing a frequency range from 50 kHz to 0.5 Hz, can be collected and analysed using simple equivalent circuit models in 50 s. It is shown that this timeframe is sufficiently short to capture the dynamic response of the fuel cell in response to changing operating conditions, thereby validating the use of multi-sine EIS as a diagnostic technique for in-situ monitoring and fault detection during fuel cell operation.

• Hancke, Ragnhild; Holm, Thomas & Ulleberg, Øystein (2022). The case for high-pressure PEM water electrolysis. Energy Conversion and Management. ISSN 0196-8904. 261. doi: 10.1016/j.enconman.2022.115642. Full text in Research Archive
• Balestra, Lorenzo; Yang, Ruochen; Schjølberg, Ingrid; Utne, Ingrid Bouwer & Ulleberg, Øystein (2021). Towards Safety Barrier Analysis of Hydrogen Powered Maritime Vessels. In ASME, Digital Collection (Eds.), ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering Volume 6: Ocean Engineering. The American Society of Mechanical Engineers (ASME). ISSN 9780791885161. doi: 10.1115/OMAE2021-60451. Full text in Research Archive Show summary

  This paper focuses on the use of safety barrier analysis, during the design phase of a vessel powered by cryogenic hydrogen, to identify possible weaknesses in the architecture. Barrier analysis can be used to evaluate a series of scenarios that have been identified in the industry as critical. The performance evaluation of such barriers in a specific scenario can lead to either the approval of the design, if a safety threshold is met, or the inclusion of additional barriers to mitigate risk even further. By conducting a structured analysis, it is possible to identify key barriers that need to be included in the system, intended both as physical barriers (sensors, cold box) and as administrative barriers (checklist, operator training). The method chosen for this study is the Barrier and Operational Risk Analysis (BORA) method. This method, developed for the analysis of hydrocarbon releases, is described in the paper and adapted for the analysis of cryogenic hydrogen releases. A case study is presented using the BORA method, developing the qualitative barrier analysis. The qualitative section of the method can be easily adapted to vessels of different class and size adopting the same storage solution. The barrier analysis provides a general framework to analyze the system and check that the safety requirements defined by the ship operator and maritime certification societies are met.

• Aarskog, Fredrik Gundersen; Danebergs, Janis; Strømgren, Trond & Ulleberg, Øystein (2020). Energy and cost analysis of a hydrogen driven high speed passenger ferry. International Shipbuilding Progress. ISSN 0020-868X. 67. doi: 10.3233/ISP-190273. Full text in Research Archive
• Ulleberg, Øystein & Hancke, Ragnhild (2019). Techno-economic calculations of small-scale hydrogen supply systems for zero emission transport in Norway. International Journal of Hydrogen Energy. ISSN 0360-3199. 45(2), p. 1201–1211. doi: 10.1016/j.ijhydene.2019.05.170. Full text in Research Archive
• Aarskog, Fredrik Gundersen; Hansen, Olav R.; Strømgren, Trond & Ulleberg, Øystein (2019). Concept risk assessment of a hydrogen driven high speed passenger ferry. International Journal of Hydrogen Energy. ISSN 0360-3199. p. 1–14. doi: 10.1016/j.ijhydene.2019.05.128. Full text in Research Archive

View all works in NVA

• Ulleberg, Øystein (2026). Hydrogen Refueling Systems for Trains – Holistic Modeling and Evaluation. Full text in Research Archive Show summary

  Abstract – Hydrogen refueling systems (HRS) are developed for different modes of transport, such as passenger cars, heavy-duty trucks, and trains. The design of HRS for trains is especially challenging because of the large amount of hydrogen that needs to be transferred. The main objective with this study was to analyze different HRS designs and operating conditions to determine the hydrogen filling time and final state of charge (SOC) in the hydrogen storage system onboard the train at the end of the refueling. A holistic “tank-to-tank” simulation model was developed and used to calculate the hydrogen filling time and final SOC for different refueling scenarios with constant mass flows or pressure ramp rates. Based on a set of system requirements derived in the Rail4EARTH project, a typical HRS hydrogen storage system and a hydrogen train storage system was selected as reference system for a modeling case study. Different HRS designs, operating conditions, and refueling scenarios were studied using as set of validated modeling tools. Sensitivity analyses on pre-cooling of medium and high hydrogen mass flow rates were performed. Investigations were also made on how pressure drops in the hydrogen piping from the HRS affect the final SOC in the train hydrogen storage. The results show that for the reference system it is possible to refuel about 180 kg of hydrogen in 30 minutes at medium high mass flow rates (100 g/s) and reasonable demands for hydrogen pre-cooling. The study also confirms that a high final SOC in the train hydrogen storage can only be achieved in a system design with a large high-pressure HRS storage.

• Holm, Thomas; Luna, Miguel Angel Leon; Bujlo, Piotr & Ulleberg, Øystein (2026). Analysis of the degradation as a function of program in polymer electrolyte membrane water electrolysis stack during an accelerated stress test. Full text in Research Archive Show summary

  Proton exchange membrane water electrolysers (PEMWE), known for high dynamic load range and fast response, are considered for integration with renewable energy sources. However, the fluctuating load introduces stress to the PEMWE systems and accelerate their degradation. Degradation rates under variable load have been estimated under different operational conditions to mimic renewable energy patterns, but most of these studies have been performed on single-cell devices or for specific conditions. Although such studies have improved our understanding of how variable current input affects the membrane and catalysts, single-cell systems do not capture effects present in multicell electrolysers. Parameters such as temperature management, current distribution, and water distribution can lead to deviations from single-cell trends, making single-cell-based degradation estimations potentially misleading. Understanding degradation patterns in medium to large-scale electrolysers during variable load and idle periods is therefore essential for predicting long-term performance and implementing mitigation strategies. In this study, we used a commercial 20-cell electrolyser stack from NEL US that represents state-of-the-art technology. The experiments were carried out at IFE’s custom-built 33 kW test station, consisting of four phases: (1) constant operation at 1 A cm-2, (2) constant operation at 2 A cm-2, (3) Variable operation between 5 and 100% load, and (4) startup/shutdown cycling. By means of polarization curve measurements throughout the experimental campaign we tracked the degradation of all the cells within the stack. From these measurements, degradation rates were estimated per cell and per phase, allowing us to construct the degradation profile of the stack. Non-linear fitting of the polarization curve was used to deconvolute the kinetic and ohmic contributions of the overpotential change. Our results show that the degradation rate follows the trend Phase 3 > Phase 2 > Phase 1 > Phase 4, with phase 3 (variable load) being the most detrimental, consistent with previous observations. Notably, a significant performance recovery was observed during Phase 4. The degradation rate was not uniform across the stack with higher degradation near the center of the stack. Polarization curve deconvolution indicated that Phases 2 and 3 induce an ohmic degradation, whereas phase one is more prone to kinetic degradation.

• Jamma, Mustapha & Ulleberg, Øystein (2026). Condition Monitoring & Controls of Fuel Cell Systems for Maritime Applications. Full text in Research Archive Show summary

  Large-scale deployment of proton exchange membrane fuel cell (PEMFC) and solid oxide fuel cell (SOFC) systems in low- and zero emission maritime applications will require improved durability, reliability, and fuel efficiency. Conventional fuel cell systems normally monitor stack voltages and the performance of key components in the balance of plant (BoP), but do not normally include very sophisticated control systems that actively try to avoid stack degradation. Inappropriate operation of fuel cells systems can lead to unnecessary high stack degradation and significant increases in hydrogen consumption. Hence, there is a need to develop more advanced fuel cell control systems based on more online monitoring and in-situ analysis of the electrochemical performance and lifetime of the fuel cell stacks. This work provides a critical literature review of condition monitoring, diagnostics, prognostics, and controls of PEMFC and SOFC systems, including an assessment of the state-of-the-art (SoA) for real-world transport applications. The review also look into different online condition monitoring methods that directly or indirectly (via black-box, grey-box, or white box models) can be used to assess the state-of-health (SoH) and remaining useful stack lifetime based on limited sensor data. Here particular attention is devoted to health-aware system control frameworks that extend beyond traditional solutions. The review explores how to incorporate learning-based models into new and more advanced fuel cell control systems and how stack degradation mechanisms and deficiencies in the BoP can explicitly be embedded into the main objective function. A set of recommendations on the design of next-generation condition monitoring and control systems will be provided, with focus on how computationally efficient and scalable control systems can increase the durability and reliability of fuel cell systems throughout their lifetime.

• Ulleberg, Øystein (2025). Modeling of Green Industrial Scale PEM Water Electrolysis Systems. Full text in Research Archive Show summary

  Brief presentation of the REHSYS project and some preliminary work done on modeling of dynamic operation of PEM water electrolysis systems.

• Hancke, Ragnhild & Ulleberg, Øystein (2025). IFE i vekst - Norsk Hydrogenforum. [Internet]. hydrogen.no. Full text in Research Archive Show summary

  IFE jobber langsiktig og smalt nok. Det har vist seg å være en suksessoppskrift.  – Vi har kontinuiteten, noe industrien ser verdien av, sier Ragnhild Hancke, avdelingsleder for Hydrogenteknologi ved IFE. 

• Ulleberg, Øystein & Hancke, Ragnhild (2025). Hurtigbåt på hydrogen kan være en god løsning for lange og tunge hurtigbåtsamband - Norsk Hydrogenforum. [Internet]. Norsk Hydrogenforum. Full text in Research Archive Show summary

  Institutt for energiteknikk (IFE) har lang og bred erfaring med forskning på hydrogendrevne hurtigbåter, som kan gi Norge to fordeler på én gang: utslippsfri transport og mulig eksportprodukt. NHF sendte beskjeden videre til stortingspolitikerne under høring om statsbudsjettet for 2026.

• Ulleberg, Øystein; Llamas-Jansa, Isabel & Møller, Amalie Bisgaard (2025). Modeling of Industrial Scale PEM Water Electrolysis Systems. doi: https:/ecs.confex.com/ecs/247/meetingapp.cgi/Paper/202692. Full text in Research Archive Show summary

  Background The first experimental activities at Institute for Energy Technology (IFE) on high-pressure (16 bar) proton exchange membrane (PEM water) electrolysis systems based on variable renewable power was performed in 2004-2008 [1]. In 2016 IFE started to develop a national research infrastructure for testing of small-scale (33 kW) pressurized (up to 200 bar) low temperature PEM water electrolyser stacks [2]. The performance of the high-pressure test rig and a prototype PEM water electrolyser stack operating at a differential pressure of 180 bar was demonstrated and documented in 2023 [3]. Modeling activities and different types of techno-economic analyses of high-pressure PEM water electrolysis have been performed in parallel to the experimental activities in several projects at IFE [4]. In 2023 there was established a new large national project in Norway on “Renewable Energy Hydrogen Systems based on PV, Wind, and Water Electrolysis” (REHSYS, 2023-2026), including a PhD at the University of Oslo (UiO) on advanced modeling and controls of industrial scale PEM water electrolyzer systems. Objectives The main objective with the REHSYS-project is to study and optimize the design and operation of industrial scale water electrolysis systems based on wind, photovoltaic (PV) solar, and PEM technology, with the aim to support technology developments required to reach the cost target of 1-2 USD per kg for renewable energy (RE) based hydrogen (H2). To achieve this the project seeks to maximize the efficiency, lifespan, and economy of RE/H2 systems by exploring system designs and operational schemes for specific locations having different weather conditions, scales, grid constraints, and prospective hydrogen off-takers. An overview of the research tasks in REHSYS is provided in the figure below; the PEM water electrolysis modeling activities are being carried out in work package 2 (WP2). Methodology To optimize the operation of RE-based PEM water electrolysis systems it is essential to develop control strategies that can mitigate the unfavorable effects of dynamic operation and safeguard the PEMWE stacks and systems. There have been performed several theoretical studies on energy management and optimization of water electrolyzer systems, but there is a lack of actual implementation and testing of model-based control strategies. Hence, there is clearly a need to better understand the technical constraints and requirements for more advanced instrumentation. The REHSYS-project will address this challenge by developing and implementing advanced system control strategies which includes PV and wind nowcasting to minimize parasitic losses, degradation, and costs. The hypothesis is that with access to precise RE-power nowcasts the system operator can make better and more qualified decisions, e.g., when to switch between hot and cold standby mode. Preliminary Results A summary of the recent PEM water electrolysis modeling efforts at IFE and some preliminary results from the modeling work in a MSc at UiO [5] and the newly started PhD of the REHSYS-project will be presented. The most recent modeling work at IFE has been performed using EES, an Engineering Equation Solver program, while the work at UiO has been performed in Matlab Simulink. The current plan in the REHSYS PhD is to develop open-source code in the Julia programming language. Preliminary results from the first modeling of a one-dimensional mechanistic PEM water electrolyser stack model and key component models for the electrolyzer balance of plants (BoP) sub-systems will be presented. References 1. Miland, H. and Ø. Ulleberg (2012) Testing of a small-scale stand-alone power system based on solar energy and hydrogen Solar Energy, 86(1): p. 666-680 2. Hancke, R., Ø. Ulleberg, R. Skattum, V. Torp, and J.E. Jensen (2019) High Differential Pressure PEMWE System Laboratory, in EFCF 2019 Low-Temperature Fuel Cells, Electrolysers & H2 Processing, Lucerne 3. Hancke, R., P. Buljo, T. Holm, and Ø. Ulleberg (2024) High-pressure PEM water electrolyser performance up to 180 bar differential pressure, Journal of Power Sources, Volume 601, 1 May, 234271, 4. Hancke, R., T. Holm, and Ø. UIleberg (2022) The case for high-pressure PEM water electrolysis, Energy Conversion and Management, 261 (2022) 115642 5. Møller, A. (2024) Modeling of the thermal and dynamic performance of a small-scale PEM water electrolyzer system, Master thesis, UiO

• Ulleberg, Øystein (2024). Forskere: Hydrogen og batterier avgjørende for nullutslipp i tungtransport. [Journal]. Teknisk Ukeblad. Full text in Research Archive
• Ulleberg, Øystein (2024). Hva kan case-studier lære oss om omstillingen til nullutslipp? Full text in Research Archive
• Fagerström, Jonathan; Myhre, Stine Fleischer; Vie, Preben Joakim Svela; Wind, Julia; Mæhlen, Jan Petter & Bryne, Bjørn [Show all 7 contributors for this article] (2024). Battery Lifetime Estimations for Freight Train on Partially Electrified Railway Route. Full text in Research Archive
• Ulleberg, Øystein & Jamma, Mustapha (2024). Design of an Advanced Energy Management Strategy for Hybrid Zero-Emission Ships​. Full text in Research Archive
• Ulleberg, Øystein & Jamma, Mustapha (2024). Design of an Advanced Energy Management Strategy for Hybrid Zero-Emission Ships. Full text in Research Archive
• Ulleberg, Øystein; Holm, Thomas; Bujlo, Piotr & Hancke, Ragnhild (2024). High-Pressure PEM Water Electrolysis: Design & Operation of a 180 bar System. Full text in Research Archive Show summary

  Proton exchange membrane water electrolysis (PEMWE) is a key technology for conversion of variable renewable energy to hydrogen. PEM water electrolyzers can cover a wide operating range and have a quick response to variable power (dynamic operation). They can also operate at high current densities and pressures. The possibility to operate at high pressures is important since this can reduce the energy demand and costs related to downstream mechanical hydrogen compression. A high-pressure experimental PEMWE laboratory system designed and built by Institute for Energy Technology has been commissioned and used for testing and characterization of a 180 bar differential pressure prototype stack (reference technology from Nel, USA). The electrolyser stack has been characterized with respect to electrochemical performance, net hydrogen production rate, and water crossover, while the overall PEMWE system has been tested with respect to its operability and performance of the thermal- and gas management systems. The results from the experimental test campaigns show that the stack voltage increase during pressurization from 5 to 30 bar is 30 % smaller than expected, but that further pressurization reduces the performance. Further analyses and theoretical studies confirm that high pressure PEMWE have a higher energy consumption than state-of-the-art electrolyser systems with mechanical compressors. However, detailed techno-economic analyses show there can be a business case for high-pressure PEMWE if the trade-off between stack efficiency and system efficiency is well-balanced. Results from the design and operation of the PEMWE System Laboratory at IFE and the 180 bar stack tests will be presented.

• Ulleberg, Øystein (2024). Hydrogen and Fuel Cells for Maritime Applications. Full text in Research Archive
• Ulleberg, Øystein (2024). Hydrogen and Ammonia for Maritime Applications. Full text in Research Archive
• Ulleberg, Øystein; Holm, Thomas; Khoza, Thulile Patricia & Hancke, Ragnhild (2024). Renewable Energy Hydrogen Systems based on PV, Wind and Water Electrolysis (REHSYS). Full text in Research Archive Show summary

  The main objective with the REHSYS-project is to study and optimize the design and operation of industrial scale water electrolysis systems based on wind, photovoltaic solar (PV), and proton exchange membrane (PEM) technology, with the aim to support technology developments required to reach the cost target of 1-2 USD per kg for renewable energy (RE) based hydrogen (H2). To achieve this the project seeks to maximize the efficiency, lifespan, and economy of RE/H2 systems by exploring system designs and operational schemes for specific locations having different weather conditions, scales, grid constraints, and prospective hydrogen off-takers. The research tasks in REHSYS are organized in the following three work packages: (1) Assessment of the variability in PV resources at different locations and development of novel nowcasting methodology, (2) Experimental testing and modelling of a PEM water electrolysis system operated with solar PV and/or wind power, and (3) Techno-economic optimization (sizing and control strategy) incorporating PV and wind nowcasting for specific use cases. Locations with existing RE and/or H2 infrastructure will be carefully selected together with the Industry Partners in the project to ensure access to data suitable for modelling and analysis. REHSYS is led by the Institute for Energy Technology (IFE) at Kjeller in Norway. IFE will contribute with research from three different departments (Solar, Hydrogen, and Energy Systems Analysis), while University of Oslo (UiO) will educate a PhD on PEM water electrolysis systems at the Department of Technology Systems (ITS) and the National Renewable Energy Laboratory (NREL) in the USA will serve as a key International Research Partner. The project is funded by the Research Council of Norway, with co-funding from four Industry Partners: Equinor, Statkraft, Hydro Havrand, and Nel.

• Ulleberg, Øystein (2024). Interdisciplinary R&D for the Green Energy Transition – Strategies and Experiences from Norway and Europe. Full text in Research Archive Show summary

  This inaugural seminar appears as part of the newly established EECMS Colloquium Series, which aims to create a platform for dialogue and exploration of potential collaborations in key areas, including Industry 5.0, Advanced Manufacturing, Quantum Computing, Quantum Communications, Next-Generation Telecommunications, energy transition, cybersecurity, AI/Machine Learning, and Data Science. The goal is to facilitate knowledge exchange, build partnerships with industries, promote collaborative research, and expand our knowledge horizon. This inaugural lecture explores the key aspects of the green energy transition, with a focus on the advancements in zero emission transport systems and renewable energy and hydrogen technologies. I will use my experiences from MoZEES (2017-2024) and HYDROGENi (2023-2030), two national Centres for Environment-friendly Energy Research (FMEs), to provide an overview of Norway's efforts in transitioning to a low-carbon future and to give some insights into the broader European context. The talk will be structured into three main sections: 1. Green Energy Transition in Norway and Europe: This section will offer a broad overview of the strategies, challenges, and opportunities in the green energy transition across Norway and Europe. It will highlight the key drivers of change and the collaborative efforts that are shaping the future of energy and transport systems 2. Zero Emission Transport Systems: Focusing on innovations in zero emission transport, this section will delve into the interdisciplinary research and development efforts that are driving advancements in road, rail, and maritime transport. The discussion will encompass a wide range of technologies (e.g., batteries and fuel cells) and approaches aimed at achieving sustainable mobility. 3. Renewable Energy Systems: This section will address the scientific and technical aspects of renewable energy systems, emphasizing the integration of various renewable energy sources and technologies (e.g., solar, wind, and water electrolysis). I will present examples of multi-disciplinary research, including modelling and analysis techniques that involve physics, electrical engineering, mathematics, and computing science. The presentation is designed to appeal to a diverse audience across different disciplines in science and engineering, including physics, electrical engineering, mathematics, and computing. It will offer a comprehensive view of the ongoing efforts and future prospects in the green energy transition, with a focus on fostering dialogue and collaboration among professionals from various fields.

• Bujlo, Piotr; Holm, Thomas; Hancke, Ragnhild & Ulleberg, Øystein (2023). Experimental Set Up for PEM Fuel Cell Testing and Monitoring. Full text in Research Archive
• Jamma, Mustapha; Bujlo, Piotr & Ulleberg, Øystein (2023). Control and Power Management of Battery-PEM Fuel Cell Hybrid Power System for Marine Propulsion Systems. Full text in Research Archive
• Holm, Thomas; Hancke, Ragnhild; Bujlo, Piotr & Ulleberg, Øystein (2023). High-Pressure PEM water electrolyser performance. Full text in Research Archive
• Ulleberg, Øystein & Jamma, Mustapha (2023). Modelling, Simulation, and Validation of a Fuel Cell/Battery-based Hybrid Power System in MATLAB/Simulink Environment. Full text in Research Archive
• Ulleberg, Øystein (2023). Renewable Energy / Water Electrolysis: Systems Lessons Learned and Way Forward. Full text in Research Archive
• Ulleberg, Øystein (2023). R&D on Battery and Hydrogen Technology for Zero Emission Transport Applications. Full text in Research Archive
• Ulleberg, Øystein (2023). Zero Emission Transport. Full text in Research Archive
• Ulleberg, Øystein (2023). MoZEES Maritime Case Study- Hydrogen-driven High Speed Passenger Ferries. Full text in Research Archive
• Jamma, Mustapha & Ulleberg, Øystein (2023). Control and Energy Management of Battery-PEM Fuel Cell Hybrid Power System for Domestic Ferry Applications. Full text in Research Archive
• Ulleberg, Øystein (2023). Nytt fra forskningsfronten. Full text in Research Archive
• Holm, Thomas; Hancke, Ragnhild; Bujlo, Piotr & Ulleberg, Øystein (2023). High-Pressure PEM water electrolyser performance. Full text in Research Archive
• Ulleberg, Øystein (2023). MoZEES presentation. Full text in Research Archive
• Bujlo, Piotr; Holm, Thomas; Hancke, Ragnhild & Ulleberg, Øystein (2023). Experimental Set Up for PEM Fuel Cell Testing and Monitoring. Full text in Research Archive
• Ulleberg, Øystein; Helgesen, Geir & Hansen, Per Morten (2023). Modeling of Hydrogen Refueling Systems for Maritime Applications. Full text in Research Archive
• Ulleberg, Øystein (2023). Omstilling av tungtransport på land - Er det mulig å nå utslippsmål med løsninger basert på batterier og hydrogen? Full text in Research Archive
• Jamma, Mustapha; Bujlo, Piotr & Ulleberg, Øystein (2023). Control and Power Management of Battery-PEM Fuel Cell Hybrid Power System for Marine Propulsion Systems. Full text in Research Archive
• Ulleberg, Øystein (2023). Hydrogen og brenselsceller for maritime anvendelse. Full text in Research Archive
• Ulleberg, Øystein; Holm, Thomas & Hancke, Ragnhild (2023). Experimental Set Up for PEM Fuel Cell Testing and Monitoring. Full text in Research Archive
• Hancke, Ragnhild; Bujlo, Piotr; Holm, Thomas & Ulleberg, Øystein (2022). High-Pressure PEMWE Stack and System Characterization. Full text in Research Archive
• Ulleberg, Øystein (2022). Modeling of hydrogen refueling – work in progress. Full text in Research Archive
• Bujlo, Piotr & Ulleberg, Øystein (2022). PEM Fuel Cell System Laboratory. Full text in Research Archive
• Ulleberg, Øystein (2022). IFE Hynor Hydrogen Technology Center. Full text in Research Archive
• Lunde-Hansen, Linda & Ulleberg, Øystein (2022). Safety in human operation during bunkering of liquid hydrogen- Preliminary findings of CRIOP scenario analysis. Full text in Research Archive
• Ulleberg, Øystein (2022). IFE Hynor - Hydrogen, sikkerhet og risiko. Full text in Research Archive Show summary

  https://esra.no/sikkerhetsutfordringer-med-fornybar-energi/

• Ulleberg, Øystein (2022). Teknologiutvikling i Norge - Blått og grønt hydrogen, ulike veier inn. Full text in Research Archive
• Hancke, Ragnhild; Bujlo, Piotr; Holm, Thomas & Ulleberg, Øystein (2022). Performance of high pressure PEM water electrolysis system. Full text in Research Archive
• Ulleberg, Øystein (2022). R&D on Battery and Hydrogen Technology for Maritime Applications. Full text in Research Archive
• Ulleberg, Øystein (2022). Introduksjon til hydrogen. Full text in Research Archive Show summary

  https://npf.no/konferansen/webinarhydrogen/

• Ulleberg, Øystein (2022). Hydrogen Technology for Zero Emission Transport Applications. Full text in Research Archive Show summary

  http://hfcnordic.dk/

• Ulleberg, Øystein (2022). Green Hydrogen Production via Water Electrolysis. Full text in Research Archive
• Ulleberg, Øystein (2022). Hydrogen for Zero Emission Transport - From R&D to Implementation. Full text in Research Archive
• Ulleberg, Øystein (2022). Zero Emission Solutions for Heavy Duty Transport Applications. Full text in Research Archive
• Hancke, Ragnhild; Bujlo, Piotr & Ulleberg, Øystein (2021). High-Pressure PEM Water Electrolysis Stack and System Characterization. Full text in Research Archive
• Ulleberg, Øystein (2021). Maritime Hydrogen Risk Management. Full text in Research Archive
• Ulleberg, Øystein (2021). Zero Emission Heavy Duty Transport – The Norwegian Approach. Full text in Research Archive
• Ulleberg, Øystein (2021). Modeling and simulation of hydrogen bunkering systems for maritime applications. Full text in Research Archive
• Ulleberg, Øystein (2021). Hydrogen og batterier–Sikkerhetsutfordringer ved anvendelse i nye energisystemer og oppskalering. Full text in Research Archive
• Hancke, Ragnhild; Bujlo, Piotr & Ulleberg, Øystein (2021). Design & Testing of a High-Pressure PEM Water Electrolyzer System Test Rig. Full text in Research Archive
• Ulleberg, Øystein (2021). EASAC Report - Key Findings & Results. Full text in Research Archive
• Ulleberg, Øystein (2021). Hydrogen Research & Development - Opportunities for Collaboration. Full text in Research Archive
• Ulleberg, Øystein (2021). MoZEES Hydrogen Roadmaps. Full text in Research Archive
• Ulleberg, Øystein (2021). Nullutslipp transport med batterier og hydrogen. Full text in Research Archive
• Aarskog, Fredrik Gundersen; Danebergs, Janis; Strømgren, Trond & Ulleberg, Øystein (2020). Energy and cost analysis of a hydrogen driven high speed passenger ferry. Full text in Research Archive
• Hansen, Olav R. & Ulleberg, Øystein (2020). Hydrogen Safety in the Maritime. Full text in Research Archive Show summary

  Joint Session with the IPHE Regulations, Codes, Standards & Safety Working Group on Maritime Considerations. Norwegian learning experiences: 1. Most important safety issues on hydrogen vessels 2. Risk and explosion study required to class a hydrogen vessel 3. Research priorities on compressed hydrogen tanks and liquid hydrogen 4. Recommendation with respect to rules

• Ulleberg, Øystein (2020). MoZEES Maritime Case Study and H2Maritime Project. Full text in Research Archive Show summary

  Presentation of MoZEES Maritime Case Study (Part 2): Method to estimate Hydrogen Demand and Total Cost of Ownership of Ferries and other Vessels Presentation of H2Martime Project: Hydrogen and Fuel Cell for Maritime Applications

• Ulleberg, Øystein (2020). Zero Emission Transport in Norway: New Markets and Applications. Full text in Research Archive Show summary

  Overview of transport markets in the EU and battery electric vehicle market in Norway. Issues related to sector coupling between energy and transport systems. Overview of MoZEES-project and results from hydrogen truck feasibility study.

• Ulleberg, Øystein (2020). Renewable Energy & Zero-Emission Electrical Transport Systems. Full text in Research Archive
• Ulleberg, Øystein (2020). Heavy-Duty Transport and Hydrogen in the Maritime. Full text in Research Archive
• Ulleberg, Øystein (2020). Decarbonization of Transport: A Norwegian perspective on Zero-Emission Transport. Full text in Research Archive
• Hancke, Ragnhild & Ulleberg, Øystein (2020). Hydrogen application in the Norwegian transport sector. Full text in Research Archive
• Ulleberg, Øystein (2020). Hydrogen for Zero-Emission Transport. Full text in Research Archive
• Ulleberg, Øystein; Gillett, William; Boulouchos, Konstantinos; Duic, Neven & Giannopoulos, George (2019). Decarbonisation of Transport – Policy Options and Ethical Challenges. Full text in Research Archive
• Ulleberg, Øystein (2019). Batteri- og hydrogenteknologi for nullutslipp i transport. Full text in Research Archive
• Ulleberg, Øystein (2019). Renewable Energy based Water Electrolysis. Full text in Research Archive
• Ulleberg, Øystein (2019). Batteri- og hydrogenteknologi for maritim sektor. Full text in Research Archive
• Ulleberg, Øystein (2019). Integrated Energy and Transport Systems - From Decarbonization to Zero Emission. Full text in Research Archive
• Ulleberg, Øystein (2019). Hydrogen i transportsektoren. Full text in Research Archive
• Ulleberg, Øystein (2019). Forsker vil ha trykksatt framfor flytende hydrogen til skip for å unngå «Tesla-fellen». [Journal]. https://tu.no. Full text in Research Archive
• Ulleberg, Øystein (2019). Sandvika-eksplosjonen: Forsker frykter at hydrogenutviklingen vil stoppe opp. [Internet]. https://e24.no. Full text in Research Archive
• Ulleberg, Øystein (2019). Hydrogeneksplosjonen ved Uno-X Hydrogenstasjonen på Kjørbo. [Radio]. https://radio.nrk.no/serie/ukeslutt. Full text in Research Archive
• Ulleberg, Øystein (2019). Hydrogen i transport. [Journal]. https://nelhydrogen.com/press-release/press-release-invitati. Full text in Research Archive
• Lunde-Hanssen, Linda Sofie & Ulleberg, Øystein (2023). H2 Safety in Human Operations – and Safety guideline. Institutt for energiteknikk. ISSN 9788270179459. Full text in Research Archive
• Schjølberg, Ingrid; Utne, Ingrid Bouwer & Ulleberg, Øystein (2022). Design of Hybrid Fuel Cell/Battery Systems for Maritime Vessels. Norges teknisk-naturvitenskapelige universitet. ISSN 9788232661374. Full text in Research Archive Show summary

  The work described in this thesis encompasses multiple aspects related to the development of hybrid marine power systems utilizing proton exchange membrane fuel cells and batteries. The focus is placed on the definition of methodologies that can help define the composition of the powerplant and its control. The developed methodologies are based upon a series of models that can simulate the powerplant, allowing the observation of the component’s behavior during operation. The analysis of the results obtained from simulations is used to evaluate the technical and economic feasibility of a specific powerplant configuration, and allows to set a benchmark for operation optimization. The first two Chapter of the thesis introduce the KPN H2Maritime project, and important aspects of hydrogen production, storage and distribution. The knowledge of these topics is fundamental in understanding the challenges encountered in relation to the adoption of hydrogen systems for transportation purposes. Such challenges are not limited to the technical limitations of fuel cells, batteries and power electronic components, but include a series of factors that are independent from the powerplant. Some of these factors are hydrogen safety, hydrogen storage and hydrogen production. Chapter three is dedicated to an overview of conventional maritime powerplants, hybrid electric powerplants and possible conversions into fuel cell/battery powerplants. The study of the conventional system, mainly the ones utilizing internal combustion engines, is fundamental as it sets a standard for performances and operational flexibility that has to be met by the newly designed hybrid systems. The definition of design criteria for hybrid powerplants utilizing proton exchange membrane fuel cells and batteries starts in Chapter four with the description of a quasi-static model to study the onboard power generation, storage and distribution during a vessel’s operations. The model is developed as a simulation tool and is used to define possible powerplant configurations based on the energy management strategy selected. The model is used as the base for the development of a software application developed in Matlab. Results obtained using the model can be used to study the technical and economic feasibility of the calculated configurations for the specific use case, or used as an input for validation into a dynamic model of the system. Two types of dynamic models have been developed and are described in Chapter five and six. These models allow to simulate the dynamic behavior of the powerplant’s components, and relative power electronics, replicating the operations of the system with a adequate degree of accuracy. Simulations carried out with the dynamic models allow a more in-depth observation of the component’s behavior during the vessel’s operations compared to the results obtained with the quasi-static model. Different powerplant layouts are tested, configuring the models of the components in different ways, and multiple energy management strategies are tested. The results obtained from these simulations can be used to compare different approaches to the powerplants configuration and control. Such results can also be utilized as a benchmark for further optimization or used as a starting point for laboratory simulations using hardware in the loop. The software and models developed for the H2Maritime project aim to fill a gap found in relation to the use high power hybrid system using fuel cells in the maritime transport industry. The development of design criteria and models to optimize operations for this type of hybrid system is key to make them an economically viable solution for ship owners. The identification of technical economic viability, even in a limited number of application, can spark the interest of many ship owners willing to innovate and to abandon polluting internal combustion engines. A transition to green hydrogen for a selected number of vessel would still imply a large reduction in the emission of pollutants and greenhouse gasses, reducing the environmental impact of maritime vessels, mitigating the effects of climate change and safeguarding marine and coastal environments.

• Sandøy, Sindre; Oltedal, Velaug Myrseth; Ulleberg, Øystein & Sorteberg, Asgeir (2022). Zero-Emission Fish Farm Powered by Wind Power and Hydrogen - A Feasibility Study. Universitetet i Bergen. Full text in Research Archive
• Tuset, Jørgen Kristoffer; Ulleberg, Øystein; Sartori, Sabrina & Hancke, Ragnhild (2021). Modelling and Validation of a Fuel Cell Electric Bus. Universitetet i Oslo. Full text in Research Archive
• Jensen, Jonas Flatgård; Sartori, Sabrina; Ulleberg, Øystein & Ragnhild, Hancke (2021). Proton Exchange Membrane Water Electrolyzer Modeling - Performance during dynamic operation. Universitetet i Oslo. Full text in Research Archive
• Østigård, Morten; Sartori, Sabrina; Ulleberg, Øystein & Gunnæs, Anette E. (2019). Advanced Modelling of NiMH Batteries: Integrating Renewable Energy Sources into EV Charging Stations. Universitetet i Oslo. Full text in Research Archive Show summary

  This thesis is devoted to the topic of energy storage system modelling, and to the integration of such systems to increase the utilisation of renewable energy. In particular, the use of a nickel-metal hydride battery storage system is considered in combination with energy produced by solar and wind to power an electric vehicle fast-charging station situated in Norway. The thesis aims to develop a flexible model for the battery energy storage system that can accurately describe battery performance and performance-reducing effects. The motivation of which is to be able to evaluate the feasibility of the charging topology in mention. A semi-empirical, battery model based on real data is designed and implemented in the Simulink modelling environment. Further, a system model is developed in the same modelling environment which uses actual data from Norwegian renewable energy producers and charging station operators. We report on the influence of renewable energy mixture, capacity sizing, production sizing and vehicle charging behaviour on the feasibility of the topology. The thesis is written as a contribution of the now finished project INTEGRARE (Intelligent prediction and integration of renewable energy sources into the Norwegian electricity grid, headed by the Department of Technology Systems). The topic is in line with an ongoing effort in the energy storage system research group to promote, design, model and validate the feasibility of energy systems powered by renewable energy sources.

• Tomasgard, Asgeir; Berstad, David Olsson; Blekkan, Edd Anders; Karstad, Per Ivar; Burheim, Odne Stokke & Dawson, James [Show all 16 contributors for this article] (2019). Hydrogen i fremtidens lavkarbonsamfunn. Center for Sustainable Energy Research (CenSES), NTNU. ISSN 9788293198314. Full text in Research Archive
• Bettzüge, Marc Oliver; Blok, Kornelius; Bradshaw, Alex; Bruce, Peter; Duic, Neven & Frank, Harry [Show all 19 contributors for this article] (2019). Decarbonisation of transport: Options and challenges. European Academies' Science Advisory Council (EASAC Secretariat). ISSN 9783804739772. Full text in Research Archive Show summary

  This report was triggered by discussions between members of the European Academies’ Science Advisory Council’s (EASAC’s) energy steering panel on the challenges faced by the European Union (EU) in the light of the Paris Agreement; in particular, the challenge of reducing emissions from the transport sector, which relies almost totally on fossil fuels. It was also stimulated by the EU energy and climate package, which was released in November 2016, entitled ‘Clean Energy for all Europeans‘, and the three packages of the EU initiative ‘Europe on the Move‘. A group of 18 experts, who had each been nominated by their national science academies, came together in July 2017 to discuss the decarbonisation of transport at a workshop with officials from six Directorates- General of the European Commission (Mobility and Transport (MOVE); Energy (ENER); Climate Action (CLIMA); Environment (ENV); Regional and Urban Policy (REGIO); and Joint Research Centre (JRC)) as well as experts from the International Transport Forum within the Organisation for Economic Cooperation and Development (ITF-OECD), the European Automobile Manufacturers’ Association (ACEA) and Local Governments for Sustainability (ICLEI). During the workshop, it was noted that greenhouse gas (GHG) emissions from the European transport sector currently represent approximately 24% of total GHG emissions from the EU and that, within this sector, the emissions were dominated by those from road transport (72%): those from passenger cars and light-duty vehicles (LDVs) amounted to about 53% and those from buses and heavy goods vehicles to about 19%. After the workshop, it was concluded that EASAC should focus on the biggest challenge, namely road transport. This report therefore examines decarbonisation of road transport, with only brief comments on rail, maritime and aviation transport. It has separate chapters on demand and supply perspectives, and adopts a framework for tackling these challenges using sustainable solutions for the long term and transitional solutions for the short term.

• Danebergs, Janis; Ulleberg, Øystein & Nordgreen, Thomas (2019). Techno-economic Study of Hydrogen as a Heavy-duty Truck Fuel, A Case Study on the Transport Corridor Oslo – Trondheim. Digitala Vetenskapliga Arkivet. Full text in Research Archive Show summary

  Norway has already an almost emission-free power production and its sales of zero-emission light-duty vehicles surpassed 30% in 2018; a natural next challenge is to identify ways to reduce emissions of heavy-duty vehicles. In this work the possibilities to deploy Fuel Cell Electric Trucks (FCET) on the route Oslo-Trondheim are analyzed by doing a techno-economic analysis. The literature study identified that in average 932 kton goods where transported between the cities. The preferred road choice goes through Østerdalen and that an average load for a long-distance truck is 16 tons. The methodology used in the study is based on cost curves for both truck and infrastructure, and a case study with various scenarios is evaluated to find a profitable business case for both an FCET fleet and its infrastructure. The cost curves for trucks are based on total cost of ownership (TCO) as a function of hydrogen price, while the levelized cost of hydrogen (LCOH) is used to present the cost of infrastructure. An analysis was made to identify the trucks component sizes and a FCET for this route would require an onboard hydrogen storage of 46 kg, a fuel cell stack with a nominal power of 200 kW, a battery of 100 kWh (min SOC 22%), and an electric motor with a rated power of 402 kW. TCO was calculated both for an FCET based on the dimensioned components and a biodiesel truck. The results show that an FCET purchased in 2020 can be competitive with biodiesel with a hydrogen price of 38.6 NOK/kgH2. While the hydrogen price can increase to 71.8 NOK/ kgH2 if the FCET is purchased in 2030. To identify the most suitable infrastructure, four different designs of hydrogen refueling stations (HRS) were compared. Furthermore, hydrogen production units (HPUs) with both alkaline or PEM type water electrolyzer were compared. The analysis in this study showed that the most cost competitive option was a 350-bar HRS without cooling, which only can serve type III onboard storage tanks. A HPU with alkaline electrolyzer was the most price competitive alternative. In case each HRS is refueling more than 7 FCETs per day, an HPU in direct connection to HRS is the preferred infrastructure setup. Three HRS are required along the route to ensure a minimum service level for the FCETs. When the TCO of the fuel cell truck and LCOH of the hydrogen infrastructure were compared for a 2020 scenario, no feasible solution was identified. The cost of installing three HRS in 2020, serving a fleet of 14-24 trucks, would cost 16.0 – 17.6 million NOK/year more than a fleet based on biodiesel trucks. In a future scenario, where both the FCET and infrastructure costs decrease due to expected learning curves, a business case can be found if at least 5 FCETs were refueling at each HRS on daily basis, which corresponds to a total fleet of approx. 24 FCETs. Finally, a set of clear recommendations on how to improve the techno-economic analysis in future studies are provided. Both by identifying areas lacking sufficient documentation and by providing steps how the tecno-economic model could be enhanced.

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