The ESI is an international benchmark for emissions from seagoing vessels. Vessels that perform better than the legal norm, 31 or more, will be rewarded with a 10% discount on port dues.
The discount was extended to 20% when vessels also have low NOx emissions in January and also applies to ships with an individual ESI-NOx score of 31.0 or more.
Low NOx emissions are achieved by using LNG as fuel or large catalysts. The discount applies to each call in the quarter concerned, with a maximum of 20 calls per single ship per quarter.
At the end of each quarter the Port of Rotterdam Authority will determine which vessels are eligible for the ESI discount. Applicable condition: at the actual time of arrival (ATA) in Rotterdam the vessel must have an ESI score of 31 points or more.
The discount for clean vessels is in line with the policy of the Port of Rotterdam Authority on sustainable port development.
When the ESI score is adjusted by the International Association of Ports and Harbours (IAPH) to below 31.0 points, or the ship is granted the status ‘inactive’, all paid out ESI discounts need to be repaid within four weeks upon first request.
For questions about the calculation of the ESI score, please contact the ESI Office (link is external) of the International Association of Ports and Harbours.