EEDI and EEOI-Measuring Ship Energy Efficiency

EEDI (Energy Efficiency Design Index) and EEOI (Energy Efficiency Operational Indicator) are two key metrics used to assess the energy efficiency of ships, particularly in the context of international shipping regulations.

EEDI: A Measure of Design Efficiency

• Purpose: EEDI is a measure of a ship’s energy efficiency during the design stage. It compares the CO2 emissions of a new ship to a baseline ship of the same type and size.
• How it Works: A ship’s EEDI is calculated based on its design specifications, such as hull form, propulsion system, and engine type. A lower EEDI value indicates a more energy-efficient design.
• Regulations: New ships built after July 2013 are required to meet specific EEDI requirements set by the International Maritime Organization (IMO).

EEOI: A Measure of Operational Efficiency

• Purpose: EEOI is a measure of a ship’s energy efficiency during operation. It compares the CO2 emissions of a ship to the transport work it performs.
• How it Works: EEOI is calculated based on the ship’s fuel consumption, transport work (measured in tonne-miles), and other relevant factors. A lower EEOI value indicates a more energy-efficient operation.
• Regulations: While EEDI is a mandatory requirement for new ships, EEOI is a voluntary measure. However, many shipping companies use it as a performance indicator to track and improve their energy efficiency.

In summary, EEDI and EEOI are complementary metrics that help assess the energy efficiency of ships. EEDI focuses on design efficiency, while EEOI evaluates operational efficiency. Both are essential tools for the shipping industry to reduce greenhouse gas emissions and promote sustainable practices.