Knowledge

Keyword: Carbon intensity

paper

An evidence-based assessment of IMO?s short-term measures for decarbonizing container shipping

Maximilian Schroer, George Panagakos, Michael Bruhn Barfod

The International Maritime Organization (IMO) has recently adopted short-term measures introducing technical standards for existing ships and a labeling system reflecting their operational carbon intensity. This paper investigates the relevant techno-economic implications from a shipowner's perspective and estimates the effect of six compliance options on six sample containerships. The study applies a new evidence-based bottom-up approach, and the results show that compliance, when possible, is not straightforward and costly. Engine power limitation is the most cost-effective option, but low power limits can lead to substantially increased sailing times (up to 793.92 h/year), which can be prohibitive. The option favors older ships with oversized engines as its effectiveness is mainly determined by the main engine load profile. In general, the effectiveness of the measures is not without limits, particularly concerning older ships and those that have already installed several options. Solutions such as market-based measures and alternative fuels, classed by IMO as medium- and long-term measures, must be considered soon.

Journal of cleaner production / 2022
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paper

The speed limit debate: Optimal speed concepts revisited under a multi-fuel regime

Roy Tan, Harilaos N. Psaraftis*, David Z.W. Wang

The purpose of this paper is to revisit speed optimization and speed reduction models for liner shipping in a multi/flexible fuel context with regards to the current ongoing speed limit debate at the International Maritime Organization (IMO). The focus is mainly on analyzing the influence of a maximum average speed limit on the optimal speeds, carbon intensity and emissions in conjunction with fleet deployment for dual fuel (DF) Neopanamax container vessels utilizing liquefied natural gas (LNG).

Transportation Research Part D: Transport and Environment / 2022
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paper

Implications of the Emission-Related Policy Environment on Existing Containerships

M. Schroer, G. Panagakos, M. Bruhn Barfod

Global warming and, correspondingly, reducing CO2 emissions is one of the most challenging tasks the world faces today. The maritime industry contributed to 2.89% of the global anthropogenic CO2 emissions. To decrease this share, the International Maritime Organization (IMO) defined, among others, the goal to reduce the carbon intensity of international shipping by 40% until 2030. In this context, the short-term measures recently adopted, in the form of a technical standard (Energy Efficiency Existing Ship Index, EEXI) and a rating scheme based on an operational indicator (Carbon Intensity Indicator, CII), mark a crucial step to achieving the mentioned goal. In addition, the EU Commission has recently introduced the FuelEU Maritime Initiative limiting the annual greenhouse gas (GHG) intensity of a ship’s energy use incorporating a reduction occurring in a five-year rhythm between 2025 and 2050. The paper investigates the practical options availed to existing containerships of different sizes and technological vintages for meeting the specific EEXI, CII, and GHG intensity reduction requirements imposed by the regulations. The investigation will be based on the actual technical and operational profiles of six sample ships and will consider a set of possible compliance options including, but not limited to, engine power limitation, waste heat recovery system, variable frequency drives, and virtual arrival. The data used originates from noon reports of existing containerships provided by a European industry leader. The ship-specific CO2 emission reduction potentials required for the impact assessment result from either literature or actual data-based calculations. Financial data is used for investigating the economic impact of the reduction requirements. Conclusions drawn include an operational advantage that pre-EEDI ships enjoy when applying engine power limitation (EPL) for EEXI compliance, the occurrence of payback periods exceeding ship lifetimes, and an estimate of the effect that onshore power supply can have on complying with the FuelEU Maritime Initiative.

7th World Maritime Technology Conference 2022 - Tivoli Congress Center, Copenhagen, Denmark / 2022
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paper

An evidence-based assessment of IMO?s short-term measures for decarbonizing container shipping

Maximilian Schroer, George Panagakos, Michael Bruhn Barfod

The International Maritime Organization (IMO) has recently adopted short-term measures introducing technical standards for existing ships and a labeling system reflecting their operational carbon intensity. This paper investigates the relevant techno-economic implications from a shipowner's perspective and estimates the effect of six compliance options on six sample containerships. The study applies a new evidence-based bottom-up approach, and the results show that compliance, when possible, is not straightforward and costly. Engine power limitation is the most cost-effective option, but low power limits can lead to substantially increased sailing times (up to 793.92 h/year), which can be prohibitive. The option favors older ships with oversized engines as its effectiveness is mainly determined by the main engine load profile. In general, the effectiveness of the measures is not without limits, particularly concerning older ships and those that have already installed several options. Solutions such as market-based measures and alternative fuels, classed by IMO as medium- and long-term measures, must be considered soon.

Journal of cleaner production / 2022
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