Green Port Dues: The Environmental Ship Index (ESI)

The ‘Environmental Ship Index’ program

Ports can implement voluntary programs to incentivize ship operators to green their ships. Green ship operators, in return, receive a benefit, such as a discount in port dues.

An example is the Environmental Ship Index (ESI). Under the auspices of the IAPH’s World Ports Sustainability Program, the Environmental Ship Index Portal enables ports and other interested parties to incentivize ships to use cleaner engines and fuels with preferential treatment offered either through discounts on port dues, bonuses or other benefits commensurate with a specified level of cleanliness. ESI is a voluntary tool which includes a formula-based evaluation of vessels’ nitrogen oxide (NOx) and sulphur oxide (SOx) emissions. The calculation also rewards vessels that are equipped to use available onshore power and which demonstrate fuel efficiency improvements over time, reducing carbon dioxide (CO2) and particulate matter (PM) emissions.

In early 2021, IAPH signed a contract with the Green Award Foundation to administer and manage the more-than 8,400-strong database of ships and 59 incentive providers already registered on the index. The strongest representation comes from the container shipping sector, with over half of the world fleet registered. Tankers (gas, chemical and oil) are also well represented with 28% of the world fleet. The focus is on growing the number of registered dry bulk and general cargo vessels as well as ro-ro and cruise vessels. Green Award is a global, independent, non-profit quality assurance organization with the primary task of certifying ship managers and vessels that go beyond the industry standards in terms of safety, quality and environmental performance. The foundation works closely with maritime authorities and classification societies, and provides data to Equasis (the database containing safety-related information on the world’s merchant fleet).

The ESI has become the established standard upon which port authorities and maritime administrations incentivize ship owners and ship owner/operators to continuously improve the environmental performance of the fleets calling at their terminals.

While ports or other public authorities could, in principle, also decide to implement strict regulation on emission criteria for ships entering the port (i.e. dirty ships are not granted access), such access restrictions have only been implemented in a few ports around the world.