Decision support tool for the implementation of CO2 reducing measures

In April 2018, the International Maritime Organization (IMO) agreed upon the target to reduce the CO2-emissions from international shipping in 2050 by 50 percent with respect to 2008 levels. As a first step to reach this target, the CO2-emissions per transport work, as an average across international shipping, need to be reduced by at least 40 per cent by 2030, compared to 2008 levels. However, due to uncertainties involved in the decision making on the implementation of CO2 reducing measures, shipowners are uncertain which actions they need to take regarding their existing fleet in order to deal with those upcoming requirements.


TNO, the Netherlands Organisation for Applied Scientific Research, has developed a tool which is able to support shipowners in the decision making process regarding the pathway of implementing technical CO2 reducing measures for their existing vessels. To put it more concretely, the tool provides the user with a timeline stating at which year certain technical CO2 reducing measures should be implemented on the vessel in order to minimize the total costs over the remaining lifetime of the vessel, while still meeting the required targets in time.

The input consists of the initial vessel parameters (e.g. operational profile, engine efficiencies, fuel mix), fuel properties (e.g. energy and carbon content, prices), economic parameters (e.g. charter day rate, discount rate, docking schedule) and a regulatory framework (e.g. emission limits, non-compliance costs). With this input, any desired set of technical CO2 measures (e.g. propulsion improving devices, anti-fouling coating, dual fuel engine) described by investment and operational costs and the expected range of fuel savings can be analysed.

The tool deals with some of the main challenges shipowners face with improving their fleet’s energy efficiency and provides them with an easy to use method to explore the options of decarbonisation for their specific vessel. The main added value with respect to similar existing tools is the ability to incorporate a regulatory framework in the analysis. For example, if a specific measure is not financially profitable by itself, it could still be a less costly option than being non-compliant with the upcoming regulations. Besides the implementation of the technical measures, the tool also provides the expected speed reduction required to be compliant with the regulations.

Example of an optimal policy for a set of CO2 reducing measures applied on a case study vessel. Following this policy, it is expected that the total costs decrease by 12 per cent with respect to the business as usual and the total CO2 emissions by 29 per cent, while being compliant with the regulations without the need the reduce the vessel’s speed.

TNO has put this tool in practice during a case study on a Post-Panamax sized bulk carrier, during which the focus was on the shipowner’s perspective; what could the shipowner do to reach the required CO2 reduction in a cost-efficient way? Results show that several measures can be implemented in the short term that result in fuel savings and that are financially viable. Furthermore, the most attractive options for this particular vessel have been identified in order to meet the regulations in 2030 and beyond.


TNO invites shipowners to participate in the further use and development of this tool. First of all, TNO intends to perform the analysis for different ship segments and sizes in order to identify those measures which have a high potential uptake throughout the whole fleet and which therefore deserve more focus by the industry. Furthermore, TNO would like to invite stakeholders to help enhancing the practical applicability of the toolset, for instance by including operational measures such as slow steaming. To conclude, the tool provides a solid base to explore the options and the impact of regulations on the way to low carbon emissions in the maritime industry.

For more Information please contact Jorrit Harmsen (Jorrit.harmsen@tno.nl).