The abatement of greenhouse gas emissions represents a major global challenge and an important topic for transportation research. Several studies have argued that energy efficiency measures for virtual arrival and associated reduced anchorage time can significantly reduce emissions from ships by allowing for speed reduction on passage. However, virtual arrival is uncommon in shipping. In this paper, we examine the causes for waiting time for ships at anchor and the limited uptake of virtual arrival. We show the difficulties associated with the implementation of virtual arrival and explain why shipping is unlikely to achieve the related abatement potential as assumed by previous studies. Combining onboard observations with seafarers and interviews with both sea-staff and shore-based operational personnel we show how charterers’ commercial priorities outweigh the fuel saving benefits associated with virtual arrival. Moreover, we demonstrate how virtual arrival systems have unintended, negative consequences for seafarers in the form of fatigue. Our findings have implications for the IMO’s greenhouse gas abatement goals.
The utilization of green energy resources for supplying energy to ships in the marine industry has received increasing attention during the last years, where different green resource combinations and control strategies have been used. This article considers a ferry ship supplied by fuel cells (FCs) and batteries as the main sources of ship's power. Based on the designers' and owners' preferences, different scenarios can be considered for managing the operation of the FCs and batteries in all-electric marine power systems. In this article, while considering different constraints of the system, six operating scenarios for the set of FCs and batteries are proposed. Impacts of each proposed scenario on the optimal daily scheduling of FCs and batteries and operation costs of the ship are calculated using a mixed-integer nonlinear programming model. Model predictive control (MPC) is also applied to consider the deviations from hourly forecast demand. Moreover, since the efficiency of FCs varies for different output powers, the impacts of applying a linear model for FCs' efficiency are compared with the proposed nonlinear model and its related deviations from the optimal operation of the ship are investigated. The proposed model is solved by GAMS software using actual system data and the simulation results are discussed. Finally, detailed real-time hardware-in-the-loop (HiL) simulation outcomes and comparative analysis are presented to confirm the adaptation capability of the proposed strategy.
The purpose of this paper is to provide an overview and discussion of potential Market Based Measures (MBMs) under the Initial IMO Strategy for the reduction of greenhouse gas (GHG) emissions from ships. In this context, some related developments are also seen as directly relevant, mainly in the context of the possible inclusion of shipping into the EU Emissions Trading System (ETS). A comparative evaluation of maritime MBMs is made using the following criteria: GHG reduction effectiveness, compatibility with existing legal framework, potential implementation timeline, potential impacts on States, administrative burden, practical feasibility, avoidance of split incentives between ship-owner and charterer, and commercial impacts. The paper breaks down potential MBMs into the following classes: Bunker levy/carbon levy MBMs, ETS (global and/or EU ETS) MBMs and other MBM proposals.
The maritime sector faces increasing pressure to reduce emissions, especially in ports, pushing governments and shipowners towards greener energy sources. Conventional diesel generator (DG) powered vessels experience increased fuel consumption and emissions during low-power demand due to fluctuating loads with changing sea conditions. Integrating battery energy storage can absorb excess power, optimize DG operation, reduce costs, and manage variable loads. Traditional shipboard power systems (SPS) rely on centralized control schemes, which pose the risk of single points of failure, scalability issues, and increased latency due to centralized decision-making. Decentralized control improves resilience and scalability by eliminating single points of failure and enabling local decision-making, which improves response times and system robustness. Although recent research has explored decentralized control strategies for AC or DC-based SPS, there is limited work on hybrid AC-DC SPS architectures. This paper proposes a decentralized control strategy for integrating multiple power sources within a hybrid AC-DC network to optimize their operation. This approach allows vessels to operate in various modes, including full diesel, hybrid, and zero emission, and seamlessly transition between these modes as needed. The effectiveness of the proposed control scheme is validated through simulation and high-fidelity software-in-the-loop (SIL) results in OPAL-RT 5700, demonstrating adaptive power sharing among different resources.
Havebrugsindustrien i nordiske lande er meget afhængig af drivhussystemer på grund af begrænsningen af det naturlige miljø og de strenge plantekrav for bestemte plantetyper. Kommercielle avlere i disse regioner støder på betydelige udfordringer med at garantere kvaliteten af planterne, mens de minimerer produktionsomkostningerne. På den ene side skal et drivhussystem forbruge en stor mængde energi for at give et tilfredsstillende klima for plantevækst. På den anden side, i de senere år, har energiprisen stigende i Europa ført til en stigning i produktionsomkostningerne for drivhuse, hvilket gør energibesparelse og optimering imperativ. Det er dog udfordrende for avlere at håndtere dette dilemma, fordi drivhusklimakontrol er et meget dynamisk og meget koblet komplekst system. Ved at analysere funktionerne i ikke-linearitet og dynamik i drivhusklimaet kan de eksisterende løsninger ikke korrekt opfylde de praktiske krav i gartneriindustrien.
For at tackle disse problemer foreslås en digital tvilling af drivhusklimakontrol (DT-GCC) rammer i denne forskning for at optimere aktuatorens driftsplan til minimering af energiforbrug og produktionsomkostninger uden at gå på kompromis med produktionskvaliteten. Arkitekturen i DT-GCC-rammen og de anvendte metoder er uddybet modulært, herunder fysisk tvilling af drivhusklimakontrol (PT-GCC) systemforståelse, design af DT-GCC-system, sammenkobling af DTGCC og PT-GCC og integration med andre digitale tvillinger (DTS).
DT-GCC omfatter en virtuel drivhus (VGH) og en multi-objektiv optimeringsbaseret klimakontrol (MOOCC) platform. VGH er den digitale repræsentation af det fysiske drivhus gennem modellering af de faktorer, der kan påvirke drivhusklimaet markant og aktuatorens driftsstrategier. MOOCC er ansvarlig for at definere drivhusklimakontrol som et multi-objektivt optimeringsproblem (MOO) og optimere driftsplanen for kunstigt lys (lysplan) og varmesystem (varmeplan). Desuden er en hierarkisk struktur af DT-GCC designet i henhold til funktionerne og ansvaret for individuelle lag, der gavner den praktiske realisering af DT-GCC med en organiseret arkitektur af design og styring.
Funktionaliteterne i DT-GCC er udviklet i en drivhusklimakontrolplatform, der er navngivet af Dynalight, som er kombineret med en genetisk algoritme (GA) ramme kaldet Controleum. Dynalight definerer et MOO -problem til at abstrahere drivhusklimakontrolsystemet med flere objektive funktioner, og omkostningerne beregnes baseret på modelleringsresultaterne fra VGH. Controleum er ansvarlig for implementeringen af GA for at generere en Pareto Frontier (PF) og endelig løsning af løsning til let plan og varmeplan.
Forskellige scenarier og tilsvarende eksperimenter er designet til at evaluere ydelsen af DT-GCC fra individuelle perspektiver, herunder VGH, MOOCC og DT-integration. Eksperimenterne på VGH verificerer forudsigelsesydelsen for kunstigt neuralt netværk (ANN) metoder på indendørs temperatur, opvarmning af forbrug og netto fotosyntese (PN). Hvad angår de to standaloneeksperimenter, garanterer resultaterne DT-GCCs evne til at kortlægge avlernes beslutningstagning om let plan og varmeplan og verificere MOOCC-ydelsen for at opfylde voksende krav og samtidig reducere energiforbruget og omkostningerne. Endelig, i DT-integrationseksperimenterne med Digital Twin of Production Twin (DT-PF) og Digital Twin of Energy System (DT-ES), afslutter DT-GCC det tilsvarende svar på forudsigelser og optimeringsanmodninger.
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. Τhe 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
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.
The purpose of this paper is to investigate a multiple ship routing and speed optimization problem under time, cost and environmental objectives. A branch and price algorithm as well as a constraint programming model are developed that consider (a) fuel consumption as a function of payload, (b) fuel price as an explicit input, (c) freight rate as an input, and (d) in-transit cargo inventory costs. The alternative objective functions are minimum total trip duration, minimum total cost and minimum emissions. Computational experience with the algorithm is reported on a variety of scenarios.
Nowadays, sea traveling is increasing due to its practicality and low-cost. Ferry boats play a significant role in the marine tourism industry to transfer passengers and tourists. Nevertheless, traditional ferry ships consume massive amounts of fossil fuels to generate the required energy for their motors and demanded loads. Also, by consuming fossil fuels, ferries spatter the atmosphere with CO2 emissions and detrimental particles. In order to address these issues, ferry-building industries try to utilize renewable energy sources (RESs) and energy storage systems (ESSs), instead of fossil fuels, to provide the required power in the ferry boats. In general, full-electric ferry (FEF) boats are a new concept to reduce the cost of fossil fuels and air emissions. Hence, FEF can be regarded as a kind of dc stand-alone microgrid with constant power loads (CPLs). This article proposes a new structure of a FEF ship based on RESs and ESSs. In order to solve the negative impedance induced instabilities in dc power electronic based RESs, a new intelligent single input interval type-2 fuzzy logic controller based on sliding mode control is proposed for the dc-dc converters feeding CLPs. The main feature of the suggested technique is that it is mode-free and regulates the plant without requiring the knowledge of converter dynamics. Finally, we conduct a dSPACE-based real-time experiment to examine the effectiveness of the proposed energy management system for FEF vessels.
Waiting times for trucks, trains, airplanes and ships in service represent apparent transport system inefficiencies, and measures to reduce these may have the potential to abate transport GHG emissions. In international shipping, transportation researchers have pointed out that reduced waiting time in association with port calls holds such promise. We explore the potential for GHG abatement through port call optimization, focusing on crews and their employers - the shipping companies. Adding new empirical evidence to the transportation literature, we confirm the existence of idle time during port calls, and go beyond this in describing the causes for it. We show how several port stakeholders, including government officials, limit the crews’ and shipping companies’ room for maneuver in relation to port calls. We also show why the process of reducing waiting time in shipping is more complex than that for onshore transport modes, where real-time traffic information guides drivers’ route choices, and reduces congestion and waiting time. Our findings have implications for both policy makers and transportation research.