The Green Shipping Glossary

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A phenomenon associated with a spinning object moving through air. The path of the spinning object is deflected by the difference in pressure of the air on opposite sides of the spinning object. The Magnus effect is dependent on the speed of rotation. As a practical implementation, in Norsepower Rotor Sails™ solution a minimal amount of electricity is used to rotate cylinders are rotated on a ships deck. This rotation combined the wind creates a powerful thrust. The thrust can then be used to throttle back the ship engine, save fuel and cut emissions. Source: &

FuelEU Maritime • Requires ships to reduce the carbon content of the fuel they use within EU and on the 50% of voyages departuring and arriving in EU. • Purpose is to support lower carbon content (alternative) fuel. • Tightening “mixing requirement” will increase the fuel cost • The ships equipped with wind propulsion (and solar) are rewarded with reward factor. (The reward factor is not something we are 100% happy with but it is better than nothing). On 14 July 2021, the European Commission presented the FuelEU maritime proposal within its Fit for 55 package, accompanied with an impact assessment. The proposed regulation introduces increasingly stringent limits on carbon intensity of the energy used by vessels from 2025, which should oblige them to use alternative fuels. It applies to commercial vessels of 5 000 gross tonnes and above, regardless of their flag (fishing ships are exempted). It covers all energy used on board when the ship is at an EU port and on voyages between EU ports, and 50% of the energy used on voyages departing from or arriving to an EU port.

The founders of Norsepower decided to start calling Norsepower’s novel products Rotor Sails in 2012. With a product name like this, it could be communicated to the market that the product is a radically modernised version of the Flettner rotor, which does exactly the same as a sail of a sailing ship. Later the name was adopted by competitors and media alike. Rotor Sail uses a minimal amount of the ship’s electricity to rotate cylinders on the ship’s deck. The rotating cylinders use the wind to generate powerful thrust. This allows the main propulsion to be throttled back. Source:


The EU’s proposed Carbon Border Adjustment Mechanism, slated to become fully operational in 2026, will put a tax on imported products in designated sectors where production-related emissions have not been taxed at the same level by the exporter’s country. Source:


The Energy Efficiency Design Index (EEDI) was made mandatory for new ships and the Ship Energy Efficiency Management Plan (SEEMP) for all ships at MEPC 62 (July 2011) with the adoption of amendments to MARPOL Annex VI (resolution MEPC.203(62)), by Parties to MARPOL Annex VI. This was the first legally binding climate change treaty to be adopted since the Kyoto Protocol. Source:

The WASP (Wind Assisted Ship Propulsion) project, funded by the Interreg North Sea Europe programme, part of the European Regional Development Fund (ERDF) to the tune of €5.4 million. Source:

The EU’s Emissions Trading Scheme. Adding to costs, the European Union (EU) is planning to bring shipping into its Emissions Trading Scheme (ETS) in 2023. Shipping lines will have to purchase allowances for 50% of emissions for voyages connecting EU and non-EU ports. Source:

A joint wind propulsion industry project that focuses on making evaluations within EEDI and EEXI and from real operational conditions. The aim is to identify the amount of fuel savings shipowners can achieve, enabling them to make informed investment decisions, while keeping in mind the upcoming CII requirements. Source:


The AER is a function of a ship’s deadweight tonnage (DWT) — how much weight it can carry in cargo, fuel, crew, fresh water, passengers, supplies, etc. — plus how much and what type of fuel it consumed and how far it traveled in the previous year. This data has been part of an IMO mandatory annual submission since 2019 for ships over 5,000 DWT. Insight Center Collection Creating A More Resilient Supply Chain Make your business more resistant to global risks. The AER is used to grade the ship A, B, C, D, or E. Vessels that receive a grade of A, B, or C will be deemed compliant that year. Vessels graded D have a three-year grace period during which the owner will have to somehow get back into compliance, and those graded E will have one year to do so. Importantly, the grading criteria will become tougher every year: The IMO is mandating a 2% annual improvement in AER from 2023 through 2030. Thus, a ship may start with a B grade in 2023, but if no changes are made after as few as six years, it could automatically become a D. If the owner cannot comply, the vessel will have to be removed from service and likely scrapped. Source:

BIMCO is one of the largest of the international shipping associations representing shipowners. Source: Wikipedia, Homepage:

The EEOI enables operators to measure the fuel efficiency of a ship in operation and to gauge the effect of any changes in operation, e.g. improved voyage planning or more frequent propeller cleaning, or introduction of technical measures such as waste heat recovery systems or a new propeller. Source:,in%20a%20cost%2Deffective%20manner.

The Ship Energy Efficiency Management Plan (SEEMP) is an operational measure that establishes a mechanism to improve the energy efficiency of a ship in a cost-effective manner. The SEEMP also provides an approach for shipping companies to manage ship and fleet efficiency performance over time using, for example, the Energy Efficiency Operational Indicator (EEOI) as a monitoring tool. Source:,in%20a%20cost%2Deffective%20manner.

Source: More commercial ships utilize wind technologies to cut emissions - DNV

The Carbon Intensity Indicator (CII) is a rating system for ships that the International Maritime Organization (IMO) developed. This will be a mandatory measure under MARPOL Annex VI, which comes into force in 2023. The measure will impact all cargo, RoPax and cruise vessels above 5,000 gross tonnage (GT) and trading internationally. The CII determines the annual reduction factor needed to continuously improve the ship's operational carbon intensity within a specific rating level. The actual annual operational CII achieved will need to be documented and verified against the required annual operational CII. This will then enable the operational carbon intensity rating to be determined on a scale of A, B, C, D or E, indicating a major superior, minor superior, moderate, minor inferior, or inferior performance level. The performance level will need to be recorded in the ship's Ship Energy Efficiency Management Plan (SEEMP). A ship rated D or E for three consecutive years will need to submit a corrective action plan to show how the required index rating (C or above) will be obtained. Source:

The United Nations agency responsible for regulating global shipping. Source:

“A Flettner rotor is a smooth cylinder with disc end plates which is spun along its long axis and, as air passes at right angles across it, the Magnus effect causes an aerodynamic force to be generated in the direction perpendicular to both the long axis and the direction of airflow.[1] The rotor sail is named after the German aviation engineer and inventor Anton Flettner, who started developing the rotor sail in the 1920s.[2]” Source:

The Energy Efficiency eXisting ship Index (EEXI) is a measure introduced by the IMO to reduce the greenhouse gas emissions of ships. The EEXI is a measure related to the technical design of a ship. Ships have to attain EEXI approval once in a lifetime, by the first periodical survey in 2023 at the latest. Source:

Hopefully you enjoyed our glossary! We will keep adding terms, so any suggestions you might have (with their explanations, if available) are more than welcome to: Thank you!