The DNV Nordic Maritime Universities Workshop is organized as a collaboration between DNV and universities in the Nordic region with a maritime related education or research line. The workshop covers all research topics related to naval architecture, maritime engineering and maritime transport, including safety, energy efficiency and environmental performance, environmental pressures, new technologies and digitalization. The 25th Nordic Maritime Universities Workshop was held on 30-31 January 2025 at the Technical University of Denmark (DTU), Lyngby Campus. The workshop has been organized and hosted by the Maritime Group at the Department of Civil and Mechanical Engineering (DTU Construct). In total we received 77 abstracts from 7 countries. This includes 23 abstracts from Denmark, 23 from Sweden, 16 from Norway, 10 from Germany, 3 from Finland, 1 from The Netherlands, and 1 from Poland. The presentation of the abstracts and the talks is carried out over two days of the workshop and in 10 sessions, distributed over 7 topics:
• Maritime Safety & Risk Reduction (17 talks)
• Structures & Ship Design (8 talks)
• Numerical Methods & Marine Hydrodynamics (14 talks)
• Ship Operations & Navigation (14 talks)
• Autonomous Shipping & Digitalization (8 talks)
• Alternative Marine Fuels (8 talks)
• Wind Assisted & Alternative Propulsion (8 talks)
This year a special issue has been initiated in International Shipbuilding Progress to commemorate the 25th Nordic Maritime Universities Workshop. All abstract presenters have been invited to submit a full paper, to be considered for publication in this journal after a peer-review process. This compendium includes the workshop program, the session details and the 77 abstracts arranged in alphabetical order.
The liner shipping industry is undergoing an extensive decarbonization process to reduce its 275 million tons of CO2 emissions as of 2018. In this process, the long-term solution is the introduction of new alternative maritime fuels. The introduction of alternative fuels presents a great set of unknowns. Among these are the strategic concerns regarding sourcing of alternative fuels and, operationally, how the new fuels might affect the network of shipping routes. We propose a problem formulation that integrates fuel supply/demand into the liner shipping network design problem. Here, we present a model to determine the production sites and distribution of new alternative fuels-we consider methanol and ammonia. For the network design problem, we apply an adaptive large neighborhood search combined with a delayed column generation process. In addition, we wish to test the effect of designing a robust network under uncertain demand conditions because of the problem's strategic nature and importance. Therefore, our proposed solution method will have a deterministic and stochastic setup when we apply it to the second-largest multihub instance, WorldSmall, known from LINER-LIB. In the deterministic setting, our proposed solution method finds a new best solution to three instances from LINER-LIB. For the main considered WorldSmall instance, we even noticed a new best solution in all our tested fuel settings. In addition, we note a profit drop of 7.2% between a bunker-powered and pure alternative fuel-powered network. The selected alternative fuel production sites favor a proximity to European ports and have a heavy reliance on wind turbines. The stochastic results clearly showed that the found networks were much more resilient to the demand changes. Neglecting the perspective of uncertain demand leads to highly fluctuating profits.
Incumbent clinker production practices fall short of meeting carbon-emission neutral targets, pressing the need to implement waste valorization approaches in cement plants to mitigate environmental impacts. However, there is a lack of knowledge on the future environmental performance of emerging waste-to-heat and fuel upcycling in clinker manufacturing. This study examines the prospective life cycle impacts of (1) solid recovered fuel (SRF) utilization and (2) on-site marine fuel production using integrated fluidized bed pyrolysis to substitute fossil fuels in clinker production and marine transportation. Environmental impacts are projected between 2025 and 2050 by applying learning effects in the foreground life cycle inventory and shared socioeconomic pathways (SSP1, SSP2), extended with the 1.9 W m−2 representative concentration pathway (SSP2-RCP1.9), in the background system. The highest decarbonization progress (−538.9 kg CO2-eq (t clinker)−1) is achieved under the SSP2-RCP1.9 development trajectory, driven by avoidance of emissions from waste management systems and converting biogenic carbon-rich municipal solid waste resources. The predicted CO2-eq impacts are found to be lower than the point source emission from raw meal calcination in several SSP scenarios, indicating that carbon-emission neutrality is attainable in combination with retrofitted carbon capture, utilization, and storage (CCUS) technologies. The assessment highlights the potential for burden shifting to other environmental impacts, e.g., particulate matter formation (+37.0 % by 2050), pointing to the need to evaluate additional pyrolysis oil upgrading and NOX emission mitigation strategies. Overall, synergizing waste pyrolysis with clinker production is found to be favourable due to (i) improved energy requirements, (ii) reduced fossil fuel use and impacts on climate change and ecosystem quality, and (iii) high potential for technological learning-driven environmental progress.
This paper investigates the significance of ports in the energy transition (ET) and decarbonisation. Ports, being vital in energy value chains, play a critical role in curbing energy use and emissions. The paper draws from the MAGPIE project, funded by the Horizon 2020 programme, which showcases energy and digital solutions in a real-world setting. The paper focuses on sustainable initiatives in 12 European sea- and inland- ports, analysed through interviews and secondary data. Findings reveal that while many ports discuss ET, few have transformed their plans into significant actions due to technological, regulatory, and financial challenges. Three core themes emerge from the review: ET infrastructure, seagoing ships and hinterland transport, and governance. Ports need more actionable strategies for ET, with port authorities spearheading the adoption of sustainable technologies through collaboration.
The hybrid combination of hydrogen fuel cells (FCs) and batteries has emerged as a promising solution for efficient and eco-friendly power supply in maritime applications. Yet, ensuring high-quality and cost-effective energy supply presents challenges. Addressing these goals requires effective coordination among multiple FC stacks, batteries, and cold-ironing. Although there has been previous work focusing it, the unique maritime load characteristics, variable cruise plans, and diverse fuel cell system architectures introduce additional complexities and therefore worth to be further studied. Motivated by it, a two-layer energy management system (EMS) is presented in this paper to enhance shipping fuel efficiency. The first layer of the EMS, executed offline, optimizes day-ahead power generation plans based on the vessel's next-day cruises. To further enhance the EMS's effectiveness in dynamic real-time situations, the second layer, conducted online, dynamically adjusts power splitting decisions based on the output from the first layer and instantaneous load information. This dual-layer approach optimally exploits the maritime environment and the fuel cell features. The presented method provides valuable utility in the development of control strategies for hybrid powertrains, thereby enabling the optimization of power generation plans and dynamic adjustment of power splitting decisions in response to load variations. Through comprehensive case studies, the effectiveness of the proposed EMS is evaluated, thereby showcasing its ability to improve system performance, enhance fuel efficiency (potential fuel savings of up to 28%), and support sustainable maritime operations.
Existing energy management strategies (EMSs) for hybrid power systems (HPSs) in hydrogen fuel cell vessels (FCVs) are not applicable to scenarios with multiple hydrogen fuel cells (FCs) and lithium batteries (LBs) in parallel, and are difficult to achieve real-time control and optimization for multiple objectives. In this paper, a bi-layer real-time energy management strategy (BLRT-EMS) is proposed. Compared with existing EMSs, the proposed BLRT-EMS implements different control/optimization objectives distributed in the execution layer EMS (EL-EMS) and the decision layer EMS (DL-EMS), which can significantly reduce bus voltage fluctuations, decrease hydrogen consumptions, improve the system efficiency, and have potential for engineering applications. In the first EL-EMS, a decentralized optimal power allocation strategy is proposed, which allows each FC system to allocate the output power ratio according to their generation costs, ensuring consistent performance of multiple FC systems (MFCS) under long-term operating conditions, and thus delaying the degradation rate of FCs. In the second EL-EMS, a distributed cooperative control strategy is proposed to achieve dynamic SoC equalization, proportional output power allocation, and accurate bus voltage restoration among multiple battery storage systems (MBSS) to extend the service life of batteries. In the DL-EMS, an energy coordination optimization strategy between MFCS and MBSS is proposed to achieve hydrogen consumption reduction and system efficiency improvement, thus enhancing the endurance performance of FCV. Finally, test results based on the StarSim experimental platform show that the proposed BLRT-EMS has faster SoC convergence speed, smaller bus voltage deviation, lower hydrogen consumption, higher system efficiency, and lower operation stress than the state-of-the-art methods.
Power-to-X plants can generate renewable power and convert it into hydrogen or more advanced fuels for hard-to-abate sectors like the maritime industry. Using the Bornholm Energy Island in Denmark as a study case, this study investigates the off-grid production e-bio-fuel as marine fuels. It proposes a production pathway and an analysis method of the oil with a comparison with e-methanol. Production costs, optimal operations and system sizing are derived using an open-source techno-economic linear programming model. The renewable power source considered is a combination of solar photovoltaic and off-shore wind power. Both AEC and SOEC electrolyzer technologies are assessed for hydrogen production. The bio-fuel is produced by slow pyrolysis of straw pellet followed by an upgrading process: hydrodeoxygenation combined with decarboxylation. Due to its novelty, the techno-economic parameters of the upgraded pyrolyzed oil are derived experimentally. Experimental results highlight that the upgrading reaction conditions of 350 °C for 2h with one step of 1h at 150 °C, under 200 bars could effectively provide a fuel with a sufficient quality to meet maritime fuel specifications. It requires a supply of 0.014 kg H2/kgbiomass. Modeling results shows that a small scale plant constrained by the local availability of and biomass producing 71.5 GWh of fuel per year (13.3 kton of methanol or 7.9 kton of bio-fuel), reaches production costs of 54.2 €2019/GJmethanol and 19.3 €2019/GJbio-fuel. In a large scale facility, ten times larger, the production costs are reduced to 44.7 €2019/GJmethanol and 18.9 €2019/GJbio-fuel (scaling effects for the methanol pathway). Results show that, when sustainable biomass is available in sufficient quantities, upgraded pyrolysis oil is the cheapest option and the less carbon intensive (especially thanks to the biochar co-product). The pyrolysis unit represents the main costs but co-products revenues such as district heat sale and biochar as a credit could decrease the costs by a factor three.
The emissions of the maritime sector caused by ship transportation and other fossil fuel sources pose a threat to the environment and human health. It drives an increasing interest in adopting electrification solutions to revolutionize the conventional maritime energy-intensive and highly polluting industry. Accordingly, this thesis is one of the pioneering attempts to implement a seaport microgrid and carbon capture shore power system of cold ironing at a port dedicated to sustainability while remaining competitive.
However, the technological and research gaps of the conventional port scheduling paradigm constitute challenges in a synergy between the two prominent maritime electrification systems of seaport microgrids and cold ironing. The incorporation of cold ironing into seaport operations introduces new challenges to handling workflow and the potential impact of such integration has not yet been quantitatively addressed. Developing strategic management to improve port performance is always an issue for the port operators. This research gap motivated this study to develop an integrated operation and energy management framework by executing forecasting and optimization techniques for coordinating these technologies toward the emission neutrality goal.
This thesis begins with an extensive review of the significant aspects of cold ironing technology and seaport microgrids. A range of factors associated with the varying demand for cold ironing in seaport microgrids, requiring advanced forecasting techniques, are described in Chapter 2. Another challenge is that the integration of cold ironing with limited capacities increases the complexity of the existing seaside operation at port namely the berth allocation problem (BAP) and quay crane allocation problem (QCAP). It prolongs the waiting time for the ships to be served at berth. Thus, a seaside operational optimization model is developed in Chapter 3 to cooperatively schedule BAP, QCAP, and cold ironing assignment problems (CIAP). Chapter 4 integrates bilevel optimization as an energy management system (EMS) framework to coordinate the joint cold ironing with the seaport microgrid concept, providing more flexibility in energy scheduling while remaining cost-effective. Finally, Chapter 5 presents the overall conclusions of the thesis, research contribution, and future recommendations.
Ammonia-fueled operation of solid oxide fuel cells is a promising alternative to their hydrogen-fueled operation. However, high ammonia decomposition rates at elevated operating temperatures of the solid oxide cells lead to a significant temperature drop at the stack inlet, causing increased thermal stresses. A multi-scale model is used in this study to investigate stack performance under direct feed and external pre-cracking of ammonia. Additionally, the effects of co- and counter-flow configurations, gas inflow temperatures, current density, and air flow rate on the stack performance under direct ammonia feed are examined. The simulation results show that for gas inlet temperatures above 750 °C, the power densities with direct feed and external cracking of ammonia differ by less than 5%. Moreover, it is indicated that the thermal stresses are lowest for the co-flow case, which decrease with decreasing gas inlet temperature and current density and with increasing air flow. Finally, this study shows that under practically applicable operating conditions, the risk of mechanical failure of the cells under direct ammonia feed operation is small.
Hydrogen can be key in the energy system transition. We investigate the role of offshore hydrogen generation in a future integrated energy system. By performing energy system optimisation in a model application of the Northern-central European energy system and the North Sea offshore grid towards 2050, we find that offshore hydrogen generation may likely only play a limited role, and that offshore wind energy has higher value when sent to shore in the form of electricity. Forcing all hydrogen generation offshore would lead to increased energy system costs. Under the assumed scenario conditions, which result in deep decarbonisatiton of the energy system towards 2050, hydrogen generation – both onshore and offshore – follows solar PV generation patterns. Combined with hydrogen storage, this is the most cost-effective solution to satisfy future hydrogen demand. Overall, we find that the role of future offshore hydrogen generation should not simply be derived from minimising costs for the offshore sub-system, but by also considering the economic value that such generation would create for the whole integrated energy system. We find as a no-regret option to enable and promote the integration of offshore wind in onshore energy markets via electrical connections.