In 2017, Energinet and TenneT, the Danish and Dutch Transmission System Operators (TSOs), have announced the North Sea Wind Power Hub (NSWPH) project. The project aims at increasing by 36 GW the North Sea offshore wind capacity, with an artificial island collecting all the power produced by wind turbines and several HVDC links transmitting this power to the onshore grids. This project brings together new opportunities and new challenges, both from a technical and economic point of view. In this regard, this paper presents three analyses regarding the design and operation of such an offshore system. First, we perform a techno-economic assessment of different grid configurations for the collection of the power produced by wind farms and its transmission to the hub. In this analysis, two frequencies and two voltage levels for the operation of the offshore grid are investigated. Our findings show that the nominal-frequency high-voltage option is the more suitable, as lowfrequency does not bring any advantage and low-voltage would results in higher costs. The second analysis is related to the differences in operating the system with low- or zero-inertia; different dynamic studies are performed for each configuration to identify proper control actions and their stability properties. Comparing the outcomes of the simulations, we observed that voltage and frequency oscillations are better damped in the zero-inertia system; however, the risk of propagating offshore faults in the connected onshore grids is mitigated with the inclusion of the synchronous condensers. Lastly, a comparison of ElectroMagnetic Transient (EMT) and phasor-mode (also known as RMS) models is presented, in order to understand their appropriateness of simulating low- and zeroinertia systems. The results show that phasor approximation modelling can be used, as long as eigen-frequencies in power network are well damped.
The purpose of this paper is to assess the status and prospects of the decarbonization of maritime transport. Already more than two years have passed since the landmark decision of the International Maritime Organization (IMO) in April 2018, which entailed ambitious targets to reduce greenhouse gas (GHG) emissions from ships. The paper attempts to address the following three questions: (a) where do we stand with respect to GHG emissions from ships, (b) how is the Initial IMO Strategy progressing, and (c) what should be done to move ahead? To that effect, our methodology includes commenting on some of the key issues addressed by the recently released 4th IMO GHG study, assessing progress at the IMO since 2018, and finally identifying other issues that we consider relevant and important as regards maritime GHG emissions, such as for instance the role of the European Green Deal and how this may interact with the IMO process. Even though the approach of the paper is to a significant extent qualitative, some key quantitative and modelling aspects are considered as well. On the basis of our analysis, our main conjecture is that there is not yet light at the end of the tunnel with respect to decarbonizing maritime transport.
The European maritime transport policy recognizes the importance of the waterborne transport systems as key elements for sustainable growth in Europe. A major goal is to transfer more than 50% of road transport to rail or waterways within 2050. However, waterways are at a disadvantage as they normally depend on transhipment and land transport to and from final destination. To meet this challenge we need a completely new approach to short sea and inland waterways shipping in Europe. This needs to include ships as well as ports and the digital information exchanges between them. A key element in this is automation of ships, ports and administrative tasks. The AEGIS project has been funded by the EU Commission to develop new knowledge and technology to address this challenge.
Acknowledgments: I thank Amanda Bille, Anna Land, Attila Marton, Britta Gammelgaard, Carl Marcus Wallenburg, Christian Durach, Christian Hendriksen, Christian Huber, Dane Pflueger, Elise Berlinski, Florian Kock, Frank Fürstenberg, Helen Peck, Ida Schrøder, Ingo Zettler, Jan Mouritsen, Jane Lister, Jennifer Rogan, Johan Lundin, Kamilla Barat, Lisa Paulsen, Lorraine van Halewijn, Marin Jovanovic, Michael Herburger, Paola Trevisan, Philip Beske-Janssen, Regina Brogna, Stefano Ponte, and Thomas Johnsen for their helpful suggestions and comments. I also thank Journal of Supply Chain Management’s editorial team, especially Mark Pagell and the anonymous associate editor, for their exceptionally constructive and thoughtful guidance. In particular, I thank Günther Metzger and Jean François Bianco, who have been very inspirational throughout my thought process. This research resulted from a collaboration between Copenhagen Business School and Nordakademie.
A numerical study on effects of the injection direction of the pilot diesel fuel on combustion and emissions under two-stroke dual-fuel marine engine-like conditions is presented in this paper. It is found that the injection direction of the pilot fuel has significant effects on the methane start of combustion as well as flame propagation direction which leads to different heat transfer trends to combustion chamber walls and flame- wall interaction. Furthermore, the injection direction of the pilot fuel changes the methane combustion intensity which leads to different trends for emission formation.
To comply with regulations stated by the United Nation's International Maritime Organization, ballast water discharged by ships must be treated to avoid the spread of invasive organisms including algae. In this study, Raman spectroscopy and multivariate data analysis was used to make a Partial Least Squares Discriminant Analysis (PLS-DA) classification model for discrimination between viable (potential invasive) and UV exposed non-viable organisms. UV exposure is commonly used as a ballast water treatment strategy and a UV based exposure method was developed such that non-viable (and dying) algae consistently could be obtained. Raman spectra from both viable and UV treated algae of Rhodomonas salina and Tetraselmis suecica were measured. A PLS-DA model was obtained to form the normalized dataset, and Cross-Validated using Venetian blinds. Based on their individual Raman spectra, it was possible to obtain 100 % discrimination between the two algal species. The model classified 92 and 91 % of the viable algae correctly for R. salina and T. suecica, respectively, as opposed to 82 and 94 % for non-viable algae. In conclusion, in this proof of concept study, Raman spectroscopy was found to have a potential for algae species identification as well as discrimination between viable and non-viable algae.
In an effort to reduce carbon emissions from international shipping, the International Maritime Organization (IMO) developed its initial strategy in April 2018 setting ambitious targets for the sector. According to the initial strategy, greenhouse gas (GHG) emissions from international shipping need to be reduced by at least 50% by 2050, and the CO2 emissions intensity by 40% by the year 2030, both compared to the 2008 levels. In order to achieve these goals, a combination of operational measures, investments in emissions abatement technology, and market-based measures will be necessary. The goals currently do not differentiate among different shipping sectors, and each sector faces different challenges. In this paper, we focus on short sea shipping (SSS), and on Ro-Pax services in particular that in general have not been examined thoroughly in the literature. We examine the emissions reduction potential of several measures, and we assess their efficacy compared with the targets set by the IMO initial strategy. The paper shows that the examined measures are not sufficient on their own to achieve the desired levels of reductions, and that a combination will be necessary, while technological solutions will need to be made more competitive through market based instruments.
This paper aims to conduct an updated literature survey on the Market-Based Measures (MBMs) currently being proposed by various member states and organizations at the International Maritime Organization (IMO) or by the scientific and grey literature as a cost-effective solution to reduce greenhouse gas (GHG) emissions from ships. The paper collects, summarizes, and categorizes the different proposals to provide a clear understanding of the existing discussions on the field and also identifies the areas of prior investigation in order to prevent duplication and to avoid the future discussion at the IMO to start from scratch. Relevant European Union (EU) action on MBMs is also described. Furthermore, the study identifies inconsistencies, gaps in research, conflicting studies, or unanswered questions that form challenges for the implementation of any environmental policy at a global level for shipping. Finally, by providing foundational knowledge on the topic of MBMs for shipping and by exploring inadequately investigated areas, the study addresses concrete research questions that can be investigated and resolved by the scientific and shipping community.
A mixed integer linear programming model is presented for the operational level cargo allocation and vessel scheduling problem of a liner shipping company in Turkey, where flow-dependent port-stay lengths, transit times and transshipment synchronizations are considered. The proposed model aims to assign shipments to routes to decrease total tardiness and construct partial vessel schedules for establishing coordination with port authorities to comply with the berthing time windows. In addition to the mathematical model, novel valid inequalities and benders decomposition algorithm are implemented. Performance of the developed algorithm is evaluated on real-life problem instances. The results show that benders decomposition with valid inequalities yields the best performance.
Ship recycling refers to the process of dismantling vessels with the purpose of extracting and recovering materials for reuse, particularly the steel. The aim of this paper is to map the supply chain of ship recycling. This exploratory and qualitative research provides a glimpse on how regulations influence the supply chain management through inter-organizational arrangements. It considers the trade-offs and combinations of financial and sustainable values that, in many ways, determine these inter-organizational arrangements. Preliminary findings show that there are conflicts of interest with the ship recycling stakeholders. Although compliance of regulations should foster better transparency in the supply chain, these regulations have not yet fully embraced social aspects, such as the fact that domestic demand and supply for steel, as well as many jobs, are dependent on this industry. On the contrary, the initiatives to regulate ship recycling might induce negative effects. This paper suggests that transaction costs analysis and the principal agency theory are two complementary theories for analyzing inter-organizational relationships in the supply chain of ship recycling.