Energy Efficiency Technologies Information Portal

This Energy Efficiency Technologies Information Portal* provides users access to energy efficiency technology information in a user-friendly format and highlights the wide spectrum of ways to potentially reduce ship fuel consumption. It builds on the work undertaken by the Ad Hoc Expert Working Group on Facilitation of Transfer of Technology for Ships (TT-EG) and supports implementation of resolution MEPC.229(65) on Promotion of technical cooperation and transfer of technology relating to the improvement of energy efficiency of ships.

Relevant information about energy efficiency measures can be found under each technology group as appropriate.

This information comprises a description of the measure, the typical associated costs, expected savings and links to more information related to the measure. All suggested energy efficiency measures are known technologies that have been applied with varying degrees of success for different vessel types. The savings potential and associated costs for each measure depends on the type of the vessel and the operation of the vessel. The savings potential and costs are therefore indicated with a range. Some measures are only applicable to some vessel types and this is also indicated in the description of the measure.


Propulsion and Hull Improvements

Energy consumers

Energy recovery

Technical Solutions

Machinery: This technology group includes measures that improve the energy efficiency of main and auxiliary engines. These include measures such as auxiliary systems optimization, optimizing heat exchangers, waste heat recovery systems, electronic auto-tuning, batteries and other solutions.

Propulsion and hull improvements:  Technologies in this group focus on improving the hydrodynamic performance of the vessel. This includes solutions that reduce the resistance of the vessel and/or also improve the propulsive efficiency of the vessel. Examples include measures such as propeller polishing, hull cleaning, PIDs (Propulsion Improving Devices), air lubrication and more.

Energy consumers: Consumers are equipment or devices that use energy when operated. Technologies in this group focus on minimizing the energy consumption by improving the device or optimizing the utilization of the device. Examples of measures in this group are frequency controllers, cargo handling systems, low energy lighting and more.

Energy recovery:  Technologies in this group focus on capturing energy from the surroundings of the vessel and using or transforming this to useful energy for the vessel. This involves measures such as application of kites, fixed sails or wings, Flettner rotors, or solar panels.

Technical solutions for optimizing the operation: Technologies in this group focus on improving the operation of the vessel more than improving the vessel itself. The list of suggested measures includes both technologies and suggestions for best practice (without direct application of a technology). Measures in this group include trim and draft optimization, speed management, autopilot adjustment and use, combinator optimizing, and others.

EEDI Formula

Improving the energy efficiency of vessels means lower fuel consumption and reduced CO2 emissions. With this concept in mind, IMO adopted the Energy Efficiency Design Index (EEDI) – the first industry-wide global regulation of CO2 emissions.

The EEDI establishes the energy efficiency requirements of individual vessels in terms of CO2 emissions per capacity-mile, i.e. grams CO2 per tonne-mile. The EEDI for a given vessel is calculated by a mathematical formula which takes into account the vessel’s theoretical energy consumption based on the engines installed, measures to improve efficiency, and the vessel’s size and capacity. The lower the calculated EEDI for a vessel, the more energy efficient the vessel is deemed to be. The regulation mandates that the calculated EEDI for a given vessel should be below a required level. The limitations will gradually become stricter towards 2025. Calculation of the EEDI is mandatory for new ships over 400 gross tonnes of the following types and keel-laid dates:

Ships with conventional propulsion contracted after 1 January 2013 or delivered after 1 July 2015:

  • Bulk carriers
  • Gas carriers (including LNG carriers)
  • Tankers
  • General cargo ships
  • Container ships
  • Refrigerated cargo carriers
  • Combination carriers
  • Passenger ships (no required level)

Ships with conventional propulsion contracted after 1 September 2015 or delivered after 1 July 2019:

  • Ro-ro vehicle carriers
  • Ro-ro cargo ships
  • Ro-ro passenger ships
  • LNG carriers (new calculation method)
  • Ships with non-conventional propulsion machinery contracted after 1 September 2015 or delivered after 1 July 2019:

Cruise passenger ships

The scope of the EEDI may be extended to include passenger ships (other than cruise ships with non-conventional propulsion machinery) and other ships with non-conventional propulsion machinery in the future.

Ships that are not propelled by mechanical means, platforms including FPSOs, and FSUs and drilling (regardless of propulsion), and cargo ships with ice-breaking capacity are exempt from the EEDI requirements.

The formula for calculating the EEDI is shown in more detail below:


The top line of the EEDI formula can be divided into four key parts:

  1. CO2 emissions due to propulsion power, PME + PPTI
  2. CO2 emissions due to auxiliary power, PAE
  3. CO2 emissions reduction through energy efficient technologies reducing the auxiliary power by generating electricity for normal maximum sea load, PAEeff. Examples include waste heat recovery and photovoltaic power generation.
  4. CO2 emission reduction through energy efficient technologies reducing the propulsion power, Peff. Examples include
    air lubrication systems and wind propulsion systems.

The bottom line of EEDI formula consists of capacity and reference speed Vref, which represent the transport work capacity of the vessel.

For more detailed information related to these parameters, please refer to Resolution MEPC.245(66) 2014 Guidelines on the Method of Calculation of the Attained Energy Efficiency Design Index (EEDI) for New Ships.

For new ships the EEDI is an important driver aimed at promoting the use of more energy efficient equipment. By improving the energy efficiency of the vessel, fuel consumption and the EEDI can be reduced. A wide range of different measures and technologies are available in this portal.

Other References

Low carbon shipping and air pollution control – Information page of IMO for air pollution and energy efficiency

EEDI – Information page of IMO on EEDI

Key findings from the Third IMO GHG Study 2014

Technology Groups

*This Information Portal is still under development and further images will be added. For suggestions and additional technologies to be included in the Information Portal, please use the GreenVoyage2050 Contact Form.

This Energy Efficiency Technologies Information Portal was developed in cooperation with DNV GL.

This webpage serves as an Information Portal for Energy Efficiency Technologies for Ships. IMO does not make any warranties or representations as to the accuracy or completeness of the information provided. View our disclaimer