Differentiated Port Dues

If ports/terminals give ship owners and operators of relatively clean ships a port due advantage, they give a direct incentive for reducing ship port emissions. Thus port dues advantages for relatively clean ships can be put into practice by two options:

  • Reducing port dues for relative clean ships while keeping port dues for the other ships unchanged and thus reducing a port’s income.
  • To apply the ‘polluter pays principle’, raising the port dues for those ships that have relatively high port emissions.

In the first case, where discounts are given, the funding of the incentive scheme could turn out to be a problem for a port. In the second case, where port dues are raised based on ship emission level, the port runs the risk of losing business to competing ports, which have not introduced such a penalty-based scheme. Another potential barrier in this context is the presence of privately owned quays in the port area that may hamper the introduction of the polluter pays principle, as this also may affect the level playing field within the port (MEPC 68 INF.16).

Some of the existing ports provide incentives for efficient and clean shipping via reduced port dues based on their regulated emissions levels. Examples are the Swedish ports that currently provide differentiated port dues based on environmental criteria. About 20-25 of the bigger ports in Sweden have differentiated port dues on the basis of the sulphur content of the fuel used and the NOx emissions from the engines on-board. For example, in Gothenburg, Sweden the port dues used to increase if the sulphur content of the fuel exceeded 0.2% (currently, the regulatory limits for Swedish ports are 0.1% due to the IMO Emissions Control Area regulations, thus the above is irrelevant).

For ships with a NOx emission level lower than 10 g/kWh, a discount is applied that increases progressively as shown in below table.


Table 8: NOx reduction incentives in port of Gothenburg (MariEMS 2017).