Ports

Environmental Ship Index (ESI) for Ports

Incentivise environmental performance using a globally established, industry-led framework

ESI provides ports with a consistent, industry-led framework to design and apply incentive schemes that reward ships performing beyond regulatory requirements.

Learn how ports use ESI

What is the Environmental Ship Index (ESI)?

The Environmental Ship Index (ESI) is a globally established, industry-led port incentive scheme that enables ports to recognise and incentivise ships performing beyond international environmental regulations.

Established in 2011 and supported by the International Association of Ports and Harbors (IAPH), ESI is recognised by the International Maritime Organization (IMO) and is today offered by more than 75 ports worldwide.

 

How ESI Works in Practice

ESI provides the reference framework. Each port retains full control over its incentive design.

1- Ships register once with ESI

Ships provide comprehensive data on emissions to air to ESI.

2- ESI scores are calculated centrally

The ESI administrator verifies the data, computes the relevant ESI scores, and provides the scores to all participating ports on a quarterly basis.

3- Ports apply incentives using ESI scores

Ports define their individual ESI incentive schemes and apply them to vessels calling at the port based on the ESI scores provided.

Why Ports Participate in ESI

Be the port of call for clean vessels. Support clean air initiatives by incentivising vessels with higher environmental performance.

Industry-led and non-commercial governance

- Backed by the International Association of Ports and Harbors (IAPH) and recognised by the International Maritime Organization (IMO) 

Participation helps attract increased vessel traffic

by continuous visibility to the +6,800 participating vessels - especially those with low emissions to air.

Enhanced visibility of clean air initiatives

towards port stakeholders through targeted schemes, individually designed by each port.

Low implementation effort

as data collection, scoring, and scheme calculation are centrally provided by the ESI administrator

Your port – Your Incentive Scheme

ESI provides a consistent and independent framework, while incentive levels and application remain fully defined by each participating port.

Supports your clean air initiatives

Incentive levels and application remain fully defined by each participating port

Applicable to ports of any size and any type of terminal

Communicate Your Environmental Engagement

Participating ports receive official certificates, digital badges, and communication materials to demonstrate participation in ESI and highlight their clean air initiatives toward stakeholders.

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Flexibility by Design: No Prescriptive Incentive Structure

  • Recognised by the IMO as a standard basis for port incentives
  • Covers CO2, SOx, NOx emissions, with additional modules evolving
  • Incentivizes vessels that perform above regulatory standards
  • IAPH member ports do not pay a participation fee
Visit the Official ESI Website

Minimal Effort for Ports: Data Collection, Verification and Score Computation by OceanScore

OceanScore supports the administration and technical operation of ESI, ensuring consistency, transparency, and reliable data handling in coordination with IAPH and ESI governing bodies.

  • Scheme operation & support

  • Data handling & validation

  • Continuous technical development

OceanScore works in close coordination with IAPH, the ESI Board, and the ESI Technical Advisory Group to ensure continuity, transparency, and consistent application of the ESI framework.

Backed by IAPH & Recognized by IMO

The Environmental Ship Index (ESI) is supported by the International Association of Ports and Harbors (IAPH) and recognized by the International Maritime Organisation (IMO). It is offered by more than 75 ports worldwide with over 6,800 vessels currently registered. 

  • 75+ ports and maritime administrations

  • 6,800+ vessels registered

  • Leading scheme of its kind globally

Talk to us about ESI for your port

Participating Ports

Autoritat Portuaria de Barcelona (Spain)
Port Ship Tax 5% incentive for ships with >=30 ESI points
More info →
Brunsbüttel Ports GmbH (Germany)
The precondition to receive a discount on Port fees for environmental-friendly ships is the presen- tation of the ESI-certificate of WPCI (World Ports Climate Initiative). Within the validity period (calendar year) 10 Ship entries in total with the best ESI-scores = 20 re- ceive a discount on port fees (in line with § 8 of the Port charges regulation) in the amount of: a) Ships with 20 up to 30 ESI-scores: 5 % discount, but 750,00 € maximum b) Shipsfrom31ESI-scoreson: 10%discount,but1.000,00€maximum After expiration of the validity period (calender year) the discount will be credited from Brunsbüttel Ports GmbH. In case of equal ESI-scores the chronological order of ship entries is relevant. The 11th ship entry and further ship entries are not entitled to receive a discount, even when the minimum ESI-score was achieved.
More info →
Copenhagen Malmö Port AB (Sweden)
CMP recognises and rewards ships with an environmentally friendly profile, by awarding a 5% rebate on the applicable Ship dues tariff (Copenhagen, Malmø, Visby) for any vessel with a valid ESI score of 80 or above. In order to avail the CMP Enviromental Incentive Scheme, the vessel owner/operator/agent request the same, latest at the time of arrival. CMP will verify the ESI score in the latest update of ESI score database and will make the reduction in the invoice accordingly.
More info →
Dunkerque-Port (France)
Ships with an ESI score > 35 capitalize points at each of their port call. These points serve as a basis for calculating the amount of the financial environmental reward granted at the end of a year. Join the charter that lay down the conditions in place is necessary to claim the reward.
More info →
Green Award Foundation (Netherlands)
Seagoing ships eligible and applying for Green Award (GA) certification will receive, upon compliance on ESI participation, the following scores in the GA ranking section for both shipping company office certification and the respective ship certification. Shipping Company office:50 points Ship: 10 points Each ship can obtain an additional score of 10 points up to 30 points for each ESI index level in steps of ESI 10 starting from ESI 0.
More info →
Groningen Seaports NV (Netherlands)

Seagoing ships with an ESI score between 20 and 40 will be granted a discount of 5% on their port dues. Scores of 40 to 60 receive a 10% discount. Scores of 60 to 80 receive 15%. Scores of 80 and above receive 20% discount.

More info →
Halifax Port Authority (Canada)
Effective January 1, 2023, all container and ro/ro vessels calling at the Port of Halifax will be eligible for a rebate (per laden vessel call) of CAD $500 for vessels with an ESI score between 20.00 and 49.99; a rebate of CAD $1,000 for vessels with an ESI score between 50.00 and 64.99; and a rebate of $1,500 for vessels with an ESI score of 65+.
More info →
Hamburg Port Authority (Germany)
Discount on the environmental component of the port fee: Vessels with an ESI air score up from 20 points will be granted a discount up to 7%. Vessels with an ESI noise score up from 40 points will be granted a discount up to 3%.
More info →
HAROPA PORT (France)
All Container, Ro-Ro, Bulk vessels with at least 44 pts (Cruise and ferries excluded) will be granted an « environmental reward » according to conditions laid down by Port of Le Havre. For full LNG powered vessels : double reward. For sail and wind powered vessels, an ESI reward of up to 50% of their ports dues on the ship according to conditions laid down by Port of Le Havre.
More info →
JadeWeserPort (Germany)
Our Environmental Ship Index (ESI) rebate is an incentive for shipowners to protect the environment: we charge lower port fees for ships which emit less sulphur into the atmosphere.
More info →
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FAQs

What is the Environmental Ship Index (ESI)?
The Environmental Ship Index (ESI) is a voluntary, industry-led environmental performance scheme that enables ports to incentivise ships demonstrating environmental performance beyond applicable regulatory requirements. It is supported by the International Association of Ports and Harbors (IAPH) and administered globally by OceanScore.
Why do ports participate in ESI?
Ports participate in ESI to: Demonstrate sustainability engagement through a globally recognised framework Incentivise ships that perform beyond regulatory requirements Apply financial incentives such as port fee reductions based on independently assessed environmental performance Support sustainability objectives beyond their direct Scope 1 and Scope 2 emissions
How does ESI support port incentive schemes?
ESI provides a consistent and independent reference framework that ports can use to design and apply their own incentive schemes. Each participating port retains full autonomy to define: - Which incentives to offer - Eligibility thresholds - How ESI scores are applied locally ESI does not prescribe incentive levels or structures.
What types of incentives can ports offer through ESI?
Incentives offered through ESI are voluntary and port-specific. They typically include: - Financial incentives such as port fee reductions - Other locally defined benefits linked to environmental performance Each port decides which incentives to offer and under which conditions. The financial incentive will need to be approved by IAPH.
Is ESI suitable for ports of all sizes?
Yes. ESI is designed to be flexible and scalable, making it applicable to ports of different sizes, traffic profiles, and development stages. Ports can implement ESI-based incentives without the need for complex local systems.
What environmental performance does ESI assess?
ESI identifies ships that perform beyond mandatory IMO requirements using verified emissions-related data. The scheme currently covers CO2, SOx, NOx and shore power usage, evolving over time in line with technical and regulatory developments.
How many ports and vessels currently participate in ESI?
ESI is offered by more than 75 ports and maritime administrations worldwide, with over 6,800 vessels registered, making it the most widely adopted environmental incentive framework in global shipping.
Is ESI recognised internationally?
Yes. ESI is: - Supported by IAPH - Integrated into IAPH’s governance structure - Recognised by the International Maritime Organization (IMO) as a standard basis for port incentives for low- and zero-carbon ships
What does participation in ESI cost for ports?
Ports that are members of IAPH do not pay a participation fee to take part in ESI. The application of incentives remains entirely at the discretion of each port.
How complex is ESI to implement for ports?
Implementation is straightforward. ESI does not require ports to build or maintain their own scoring systems. Scheme operation, data handling, and technical administration are managed centrally by the ESI administrator.
What is OceanScore’s role in ESI?
Under agreement with IAPH, OceanScore acts as the globally mandated administrator of the Environmental Ship Index. OceanScore manages all the data collection, verification and score computation, making it easy for ports to offer ESI incentives. OceanScore supports: - Scheme operation and technical administration - Data handling and validation - Ongoing user support - Continuous development in coordination with IAPH and ESI governing bodies OceanScore does not define port incentives and does not own the scheme.
Does ESI replace regulatory requirements?
No. ESI does not replace regulatory compliance. It complements regulation by incentivising environmental performance beyond mandatory requirements, allowing ports to reward ships that go further than the regulatory baseline.
Where can ports learn more or get started?
Official information about ESI and access to the scheme is available at www.environmentalshipindex.org Ports interested in discussing ESI implementation can also contact OceanScore as the scheme administrator.

Interested in offering ESI-based incentives at your port?

Talk to OceanScore, the globally mandated administrator of the Environmental Ship Index.

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