Towards the end of 2008 and in early 2009 CE Delft developed the Environmental Ship Index (ESI) at the request of the World Port Climate Initiative (WPCI) and in collaboration with the five largest seaports in Western Europe. The ESI can be used by ports to promote cleaner shipping. The Port of Rotterdam has announced that in 2011 it will give the cleanest vessels a discount on harbour dues.
The ESI is explained in this brochure, to which CE Delft contributed.
In 2009 a survey was carried out to test the ESI formulae, with the following specific goals:
The report presents the survey results and analysis. There was found to be sufficient data on board ships for calculating the ESI scores. It could also be concluded that the ESI is a good indicator for the emissions performance of shipping. There are major differences in ESI score among vessels, because of differences in the sulphur content of the fuels burned and differences in engine NOx emissions.