Environmental ship index underway

On request from several leading ports in northwestern Europe, including Le Havre, Antwerp, Rotterdam, Bremen and Hamburg, the Dutch research institute CE Delft has developed an environmental ship index to be implemented voluntarily from 2010 to promote greener shipping.
   The index identifies vessels that perform better in terms of emissions of nitrogen oxides (NOx) and sulphur dioxide (SO2) than under current international regulations.
   The proposed index ranges from 0 for a ship that meets the current environmental average performance to 100 for a ship that emits no SO2 and NOx, and reports its performance index for carbon dioxide.
   Reductions in emissions are taken into account both at berth and at sea – both in emission control areas (ECAs) and on the high sea. The proposed index gives a much higher relative weighting to emissions at berth and in the ECAs, as these are believed to have a greater impact on health and the environment in and near the ports. For reasons that are rather unclear it is suggested that NOx emissions should have twice the weighting of SO2 emissions.

Emissions of the greenhouse gas carbon dioxide (CO2) are not directly reflected in the index. The reason stated is that there is no established baseline for the CO2 efficiency of ships. However, in order to encourage ships to report CO2 so that a baseline could be established in the future, ships can earn a reporting award for CO2.
   Emissions of health-damaging particulate matter (PM) are not reflected in the index, the reason being that PM emissions from ships are neither certified nor regulated. Including them would, according to the authors, involve measuring them and establishing a baseline, which would make the index costly and complex. However, it should be noted that measures to cut SO2 emissions, such as switching to low-sulphur distillate fuel, also significantly reduce PM emissions. Since emissions of boilers and incinerators on board ships are not regulated, they are not included in the index. Similarly, engines below 130 kilowatts (kW) are not included. Also shore-side electricity is not accounted for in the proposed index.

Data on a ship’s NOx emissions should be calculated using the official certificates for the engines fitted to each ship, while data on SO2 emissions should be established after inspection of the bunker fuel delivery notes for a ship either over the past year or over another period. It is however not clear from the report how the use of exhaust after-treatment devices such as selective catalytic reduction (SCR) or SO2 scrubbers could be accounted for.

Christer Ågren

Proposal for an Environmental Ship Index – Air pollutants and CO2 (2009). 42 pages. Publication number: 09.7848.05. By E. den Boer, J. Faber, and D. Nelissen. Published by CE Delft, The Netherlands. Available from www.ce.nl

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