Here are the salient features of EEXI, EEOI, Enhanced SEEMP, and CII as per MARPOL Annex VI:

(i) EEXI (Energy Efficiency Existing Ship Index)

• Purpose: A technical measure to reduce greenhouse gas (GHG) emissions by improving the energy efficiency of existing ships through design and technical modifications.
• Applicability: Applies to existing ships of 400 GT and above engaged in international voyages, for specific ship types (e.g., bulk carriers, gas carriers, tankers, container ships, general cargo ships, refrigerated cargo carriers, combination carriers, ro-ro cargo ships, ro-ro passenger ships, cruise ships).
• Nature: It is a one-time certification requirement. Each ship must calculate its attained EEXI and demonstrate that it is below the required EEXI.
• Calculation: Based on the ship's design parameters, such as installed engine power, capacity (deadweight or gross tonnage), and a reference speed.
• Compliance: Ships must meet the required EEXI at their first annual, intermediate, or renewal survey after 1 January 2023.
• Outcome: Aims to ensure that existing ships meet a minimum energy efficiency standard, similar to the EEDI for new ships.

(ii) EEOI (Energy Efficiency Operational Indicator)

• Purpose: An operational measure used to monitor and track the energy efficiency of a ship in operation over a period, typically a voyage or a year.
• Applicability: Primarily a voluntary tool for ship operators to assess the energy efficiency of their fleet. However, it is a mandatory component for data collection under the IMO Data Collection System (DCS) and for calculating CII.
• Calculation: Based on actual operational data, including fuel consumption, cargo carried (or capacity), and distance traveled during a specific period.
• Metric: Expressed as grams of CO2 emitted per tonne-mile (gCO2/tonne-mile) or similar operational metric.
• Usage: Provides valuable data for internal management, benchmarking, and identifying areas for operational improvements. It is a key input for the SEEMP and for calculating the CII.
• Nature: It is a monitoring tool, not a direct regulatory compliance requirement in itself, but its data feeds into mandatory regulations.

(iii) Enhanced SEEMP (Ship Energy Efficiency Management Plan)

• Purpose: A mandatory management plan that establishes a mechanism for ships to improve their energy efficiency over time and reduce GHG emissions.
• Applicability: Mandatory for all ships of 400 GT and above engaged in international voyages.
• Structure: The enhanced SEEMP (often referred to as SEEMP Part III) specifically addresses the Carbon Intensity Indicator (CII) requirements.
• Key Components:
  • Planning: Outlines the methodology for calculating the ship's attained annual operational CII.
  • Implementation: Details the measures the ship will take to improve energy efficiency and achieve the required CII.
  • Monitoring: Specifies how the ship's operational performance will be monitored and recorded.
  • Self-evaluation & Improvement: Includes procedures for self-evaluation and corrective actions if the ship's CII rating is unsatisfactory.
• Approval: The SEEMP Part III must be developed, submitted to, and approved by the ship's Administration or a Recognized Organization (RO).
• Review: It is a living document that requires annual review and updates to reflect operational changes and stricter CII targets.

(iv) CII (Carbon Intensity Indicator)

• Purpose: An operational measure to rate the annual carbon intensity of ships and drive continuous improvement in their operational energy efficiency.
• Applicability: Mandatory for ships of 5,000 GT and above engaged in international voyages.
• Calculation: Calculated annually based on actual operational data (fuel consumption, distance traveled, and cargo carried/capacity) collected through the IMO DCS.
• Metric: Expressed as grams of CO2 per tonne-mile (gCO2/tonne-mile) or similar operational metric.
• Rating System: Each ship receives an annual operational carbon intensity rating from A to E (A being the best, E being the worst) based on its attained CII compared to a required CII.
• Compliance & Corrective Action:
  • Ships rated D for three consecutive years or E for one year must develop a corrective action plan as part of their SEEMP Part III, outlining how they will achieve a C rating or better.
  • The required CII becomes progressively stricter each year, aiming for a 2% annual reduction in carbon intensity from 2023 to 2026.
• Outcome: The rating is recorded in the ship's Statement of Compliance and aims to incentivize shipowners to optimize operations and implement energy-efficient technologies to improve their rating.