| 1. |
- Hörteborn, Axel, 1986, et al.
(författare)
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Economic incentives and technological limitations govern environmental impact of LNG feeder vessels
- 2023
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 429
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Tidskriftsartikel (refereegranskat)abstract
- In the transition to sustainable shipping, Liquified Natural Gas (LNG), is proposed to play a role, reducing emissions of sulphur and nitrogen oxides, and particulate matter. However, LNG is a fossil fuel and there is an ongoing discussion regarding the extent of methane slip from ships operating on LNG, challenging the assumptions of LNG as a sustainable solution. Here we show another aspect to consider in the environmental assessment of shipping; LNG feeder vessels may spend as much as 25% of their time at sea just running the ship to ensure the pressure in the tanks are not exceeded, i.e., run time not directly attributed to the shipment of gas from one port or ship, to another. In other words, the economic incentives are currently allowing for roughly 32% increase of the ships’ operational emissions and discharges and increased navigational risks. Most coastal areas are heavily affected by anthropogenic activities and e.g., in the Baltic Sea there is consensus among the HELCOM member states that the input of nutrient and hazardous substances must be reduced. Even if the LNG feeder vessels are currently few, the possibility to reduce their environmental impact by 32% should be an attractive opportunity for future policy measures and investigation of technological solutions of the problem.
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| 2. |
- Ancona, M. A., et al.
(författare)
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Efficiency improvement on a cruise ship: Load allocation optimization
- 2018
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904. ; 164, s. 42-58
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Tidskriftsartikel (refereegranskat)abstract
- Last years have been characterized by a worldwide increasing attention towards the reduction of fuel consumption and carbon dioxide emissions. Several industrial fields, as well as the civil and residential sector, have introduced innovative approaches for the design and the operation of energy systems. These actions are aimed to reach higher values of energy conversion efficiency, also including an increase in the use of renewable resources. In this context, especially in the sector of cruise ships, further efforts are required to improve the energy efficiency of the employed energy systems. The aim of this paper is to propose an optimization framework based on genetic algorithms in order to maximize the energy efficiency and minimize both the fuel consumption and the thermal energy dissipation, by optimizing the load allocation of the ship energy systems. To this purpose, different strategies for the energy systems on board of an existing cruise ship are proposed and analyzed. In particular, two main engines configurations have been defined: standard (current logic of operation maintained) and hybrid configuration. For each proposed strategy – being the ship a particular and interesting application of isolated energy grid (i.e. a grid without connections with electric and fuel national grids) – an in-house-developed software has been adapted and applied to optimize the load allocation of the various energy systems. Furthermore, an economic and environmental analysis has been carried out, in order to point out the benefits – or the eventual limits – related to the proposed solutions. The considered approach is based on the concept of introducing economically and structurally suitable modifications to the current cruise energy systems configuration, in order to reach the goal of increasing the energy efficiency. The carried out analysis shows that the hybrid strategies allow to reach the best results in terms of energy (fuel consumption and heat dissipation reduction), economic and environmental points of view.
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| 3. |
- Andersson, Karin, 1952, et al.
(författare)
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Shipping and the Environment - Improving Environmental Performance in Marine Transportation
- 2016
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- This book focuses on the interaction between shipping and the natural environment and how shipping can strive to become more sustainable. Readers are guided in marine environmental awareness, environmental regulations and abatement technologies to assist in decisions on strategy, policy and investments. You will get familiar with possible paths to improve environmental performance and, in the long term, to a sustainable shipping sector, based on an understanding of the sources and mechanisms of common impacts. You will also gain knowledge on emissions anddischarges from ships, prevention measures, environmental regulations, and methods and tools for environmental assessment. In addition, the book includes a chapter on thebackground to regulating pollution from ships. It is intended as a source of information for professionals connected to maritime activities as well as policy makers and interested public. It is also intended as a textbook in higher education academic programmes.
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| 4. |
- Andersson, Karin, 1952
(författare)
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The shipping industry and the climate
- 2022
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Ingår i: Sustainable Energy Systems on Ships: Novel Technologies for Low Carbon Shipping. - 9780128244715 ; , s. 3-25
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- As by 2020, the past six years, including 2020, are likely to be the six warmest years on record and the global mean temperature was 1.2°C above the preindustrial level [1]. International agreements, the Kyoto Protocol (1997) and the Paris agreement (2016), has set the aim to keep a global temperature rise during this century well below 2°C above pre-industrial levels. The anthropogenic inflow of GHGs to the atmosphere from the shipping industry was estimated by the IMO to totally around 2.5–3% of the global emissions in 2018 (or 1076 million tonnes). This is an increase by 9.6% since the previous study in 2014. The IMO projects the future emissions to increase from 1000 Mt CO2 in 2018 to 1000 to 1500 Mt CO2 in 2050 in a “Business as Usual”, BAU, scenario. Two years after the Paris agreement, the IMO adopted a vision, followed by a plan for implementation, in which a global goal of 50% reduction in GHG emissions from shipping by 2050 compared to 2008, and a total phase-out “within this century” is stated. Action from the IMO has started with a data collection system for fuel oil consumption. Ships of >5000 gross tonnage are required to collect consumption data fuel oil use and data on transport work. The European Union has started work on emission decrease with demands on Monitoring, Reporting and Verification of CO2 emissions from large ships (>5000 tonnes) using EU ports. Also here further measures are expected. At present here are many different initiatives, internationally, from countries as well as from shipping companies and shipowners to find ways towards “zero carbon shipping”. The different regulations and incentives introduced will help on the way, but still there is a need for more strict regulations or stronger incentives. The present initiatives give a large potential to make shipping and sea transport an important player also in a carbon neutral, sustainable society.
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| 5. |
- Brynolf, Selma, 1984, et al.
(författare)
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Compliance possibilities for the future ECA regulations through the use of abatement technologies or change of fuels
- 2014
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Ingår i: Transportation Research Part D: Transport and Environment. - : Elsevier BV. - 1361-9209. ; 28, s. 6-18
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Tidskriftsartikel (refereegranskat)abstract
- The upcoming stricter emission control area (ECA) regulations on sulphur and nitrogen oxides (NOX) emissions from shipping can be handled by different strategies. In this study, three alternatives complying with the ECA regulations for sulphur as well as Tier III for NOX are presented and compared using life cycle assessment. None of the three alternatives will significantly reduce the life cycle impact on climate change compared to heavy fuel oil (HFO). However, all alternatives will reduce the impact on particulate matter, photochemical ozone formation, acidification and terrestrial eutrophication potential. The assessment also highlighted two important regulatory aspects. Firstly, the need to regulate the ammonia slip from use of selective catalytic reduction (SCR) and secondly the need to regulate the methane slip from LNG engines. In addition, an analysis of the use of SCR in Swedish waters is presented showing that SCRs have been used on a number of ships already giving significantly reduced NOX emissions.
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| 6. |
- Brynolf, Selma, 1984, et al.
(författare)
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Environmental assessment of marine fuels: liquefied natural gas, liquefied biogas, methanol and bio-methanol
- 2014
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 74, s. 86-95
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Tidskriftsartikel (refereegranskat)abstract
- The combined effort of reducing the emissions of sulphur dioxide, nitrogen oxides and greenhouse gases to comply with future regulations and reduce impact on climate change will require a significant change in ship propulsion. One alternative is to change fuels. In this study we compare the life cycle environmental performance of liquefied natural gas (LNG), liquefied biogas (LBG), methanol and bio-methanol. We also highlight a number of important aspects to consider when selecting marine fuels. A transition to use of LNG or methanol produced from natural gas would significantly improve the overall environmental performance. However, the impact on climate change is of the same order of magnitude as with use of heavy fuel oil. It is only the use of LBG and bio-methanol that has the potential to reduce the climate impact. The analysis did not show any significant differences in environmental performance between methane and methanol when produced from the same raw materials, but the performance of the methanol engines are yet to be validated.
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| 7. |
- Brynolf, Selma, 1984
(författare)
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Environmental assessment of present and future marine fuels
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Our globalised world is connected by shipping, an industry powered by one of heaviest and dirtiest products of refining: heavy fuel oil. Tougher environmental regulations are now challenging the industry to take action. Ship-owners and operators are faced with the choice of installing exhaust gas cleaning technologies or switching to a different fuel altogether. The primary purpose of this thesis was to assess the environmental performance of present and future marine fuels and to evaluate potential methods and tools for their assessment.Two different system approaches are used in this study: life cycle assessment (LCA) and global energy systems modelling. LCA is a well-established method for assessing the environmental performance of fuels. This type of assessment was complemented with the use of the Global Energy Transition (GET) model to investigate cost-effective fuel choices based on a global stabilisation of CO2 emissions and the global competition for primary energy sources. The GET model includes all energy sectors and considers the interactions among them, but it is limited in scope to CO2 emissions and costs. The LCAs involve a holistic systems perspective that includes the entire life cycle and various types of environmental impacts, but they are limited to analyses of one product or service at a time. These methods provide insights that are both contradictory and complementary.This study concludes that there is substantial potential for reducing the environmental impact of shipping through a change in fuel types and/or the use of exhaust abatement technologies. A switch from heavy fuel oil to any of the alternatives investigated in this study reduces the overall environmental impact of marine fuels. The GET model indicates that it is cost-effective to phase out the use of crude oil-based fuels in the shipping sector and replace these fuels with the use of natural gas-based fuels during the next few decades. Based on the LCA results, the use of biofuels may be one possible way to reduce the impact of shipping on the climate, but biofuels may only be a cost-effective fuel in shipping if the corresponding annual available bioenergy resources are sufficiently large. Three important implications are highlighted: the importance of reducing the NOX emissions from marine engines, the need to regulate the methane slip from gas engines and the fact that a change in fuels may not reduce the impact of shipping on the climate.
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| 8. |
- Jasinski, Michal, et al.
(författare)
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Operation and Planning of Energy Hubs Under Uncertainty - a Review of Mathematical Optimization Approaches
- 2023
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 11, s. 7208-7228
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Tidskriftsartikel (refereegranskat)abstract
- Co-designing energy systems across multiple energy carriers is increasingly attracting attention of researchers and policy makers, since it is a prominent means of increasing the overall efficiency of the energy sector. Special attention is attributed to the so-called energy hubs, i.e., clusters of energy communities featuring electricity, gas, heat, hydrogen, and also water generation and consumption facilities. Managing an energy hub entails dealing with multiple sources of uncertainty, such as renewable generation, energy demands, wholesale market prices, etc. Such uncertainties call for sophisticated decision-making techniques, with mathematical optimization being the predominant family of decision-making methods proposed in the literature of recent years. In this paper, we summarize, review, and categorize research studies that have applied mathematical optimization approaches towards making operational and planning decisions for energy hubs. Relevant methods include robust optimization, information gap decision theory, stochastic programming, and chance-constrained optimization. The results of the review indicate the increasing adoption of robust and, more recently, hybrid methods to deal with the multi-dimensional uncertainties of energy hubs.
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| 9. |
- Perera, Amarasinghage Tharindu Dasun, et al.
(författare)
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Climate resilient interconnected infrastructure: Co-optimization of energy systems and urban morphology
- 2021
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 285
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Tidskriftsartikel (refereegranskat)abstract
- Co-optimization of urban morphology and distributed energy systems is key to curb energy consumption and optimally exploit renewable energy in cities. Currently available optimization techniques focus on either buildings or energy systems, mostly neglecting the impact of their interactions, which limits the renewable energy integration and robustness of the energy infrastructure; particularly in extreme weather conditions. To move beyond the current state-of-the-art, this study proposes a novel methodology to optimize urban energy systems as interconnected urban infrastructures affected by urban morphology. A set of urban morphologies representing twenty distinct neighborhoods is generated based on fifteen influencing parameters. The energy performance of each urban morphology is assessed and optimized for typical and extreme warm and cold weather datasets in three time periods from 2010 to 2039, 2040 to 2069, and 2070 to 2099 for Athens, Greece. Pareto optimization is conducted to generate an optimal energy system and urban morphology. The results show that a thus optimized urban morphology can reduce the levelized cost for energy infrastructure by up to 30%. The study reveals further that the current building form and urban density of the modelled neighborhoods will lead to an increase in the energy demand by 10% and 27% respectively. Furthermore, extreme climate conditions will increase energy demand by 20%, which will lead to an increment in the levelized cost of energy infrastructure by 40%. Finally, it is shown that co-optimization of both urban morphology and energy system will guarantee climate resilience of urban energy systems with a minimum investment.
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| 10. |
- Thies, Fabian, 1984, et al.
(författare)
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Wind-assisted, electric, and pure wind propulsion - the path towards zero-emission RoRo ships
- 2023
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Ingår i: Ships and Offshore Structures. - : Informa UK Limited. - 1754-212X .- 1744-5302. ; 18:8, s. 1229-1236
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Tidskriftsartikel (refereegranskat)abstract
- Electrical and wind propulsion, together with energy stored in batteries and renewable energies harnessed onboard, can lead the way towards zero-emission ships. This study compares wind propulsion solutions and battery storage possibilities for a RoRo ship operating in the Baltic Sea. The ship energy systems simulation model ShipCLEAN is used to predict the performance of the zero-emission ship in real-life operating conditions. The study showcases how ships can be transferred from a conventional, diesel-powered to a zero-emission ship. For the zero-emission ship, all energy needed for auxiliaries and propulsion is taken from renewable sources onboard or from batteries. Challenges and opportunities, as well as necessary adaptions of the route and logistics, are discussed. Results of the study present which wind propulsion technology is the most suitable for the example RoRo ship, and how the installation of suitably sized battery packs for zero-emission operation affects the cargo capacity of the ship.
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