The shipping industry is working to reduce its environmental impact. The International Maritime Organization (IMO) has introduced regulations like EEXI and CII to improve energy efficiency and reduce greenhouse gas emissions. To comply with these regulations, shipping companies need to adopt various strategies, including energy-efficient technologies, vessel modifications, and optimized operational practices, according to Marine Insight.
Overview of Carbon Intensity Indicator (CII)
CII is an operational efficiency measure of a vessel that applies to ships of 5,000 gross tonnage and above. CII is a function of grams of CO2 emitted per cargo-carrying capacity and nautical miles. The annual operational CII verification will be carried out, and based on the vessel’s performance, they will be rated on a scale from A to E, with A being the most efficient and E the least.
Ships that fall into the D rating for three consecutive years or E rating for one year must submit a corrective action plan to improve their rating. The performance of the ship is recorded in a “Statement of Compliance”, and the same is further elaborated in the respective vessel’s Ship Energy Efficiency Management Plan (SEEMP). The below process shows the overview of the CII process.
How CII is Calculated?
- Attained CII is the actual carbon intensity indicator value calculated from annual data reported by ship owners per vessel.
Total transport work by a vessel is obtained using data from the IMO Data Collection System (IMO DCS).
Correction factors and voyage adjustments for CII calculations shall be applied to calculate the attained annual operational CII.
- Required CII is the carbon intensity indicator value set by the IMO regulations for each vessel type annually.
Challenges in Carbon Intensity Indicator (CII) Compliance
Achieving CII compliance has several operational and regulatory challenges:
- Inconsistent Operational Profiles
CII rating gets affected significantly depending on operational conditions such as voyage length, routes, port waiting times, or specific cargo requirements, thus making it challenging to maintain consistent ratings, especially for ships operating in trades with unpredictable schedules or shorter voyages where fuel consumption is higher per distance travelled.
- Lack of Flexibility in Fleet Management
CII compliance requires ongoing monitoring, which reduces operational flexibility. A vessel with a lower CII rating may need to reduce speed or modify its route, which can disrupt commercial schedules and impact charter commitments. Shipowners may find themselves facing difficult choices between maintaining operational efficiency and adhering to CII regulations.
Additionally, for fleets with a diverse mix of vessel types and ages, applying uniform decarbonization strategies becomes impractical. Older vessels are less efficient, making them more vulnerable to poor CII ratings, but retrofitting or replacing these vessels can be capital-intensive.
- Unclear Long-Term Regulatory Path
While CII is already in force, the IMO’s roadmap for decarbonization is far beyond the current regulation, which creates uncertainty for shipowners planning fleet upgrades. The prospect of future, more stringent regulations leaves operators hesitant about investing in technologies or operational changes that may soon be outdated or insufficient.
Decarbonisation Solutions for Compliance
To meet CII regulatory requirements and avoid penalties, shipowners must focus on reducing the carbon intensity of their vessels. While the distance travelled by the vessel is commercially controlled, here are some of the most effective long-term strategies that deal directly with CO2 Emissions :
- Operational Adjustments
Operational measures can also play a crucial role in reducing a vessel’s carbon intensity.
- Speed Optimization
- Voyage Planning
- Trim and Draft Optimization
- Engine Load Management
- Baller Management
- Cold Ironing (AMP)
- Variable Frequency Drives (VFD’s)
- Energy-Efficient Technologies (EETs)
Energy-efficient technologies (EETs) are vital in improving the efficiency of ships; these devices can reduce fuel consumption and CO2 emissions, making them an essential tool for compliance. Vessel EQ by Azolla provides insights as to which EETs are a viable solution.
- Pre-Swirl Ducts
- Wake Equalising Ducts
- Rudder Bulbs
- Propeller Boss Cap Fins (PBCF)
- Flettner Rotor
- Turbo-Sails
- Wind-Assisted Propulsion Systems (WAPS)
- LED Lighting
- Hull Modifications
Modifying the hull of a vessel can significantly impact its hydrodynamic efficiency, leading to reduced fuel consumption and lower CO2 emissions.
- Hull Coatings
- Bulbous Bow Modifications
- Hull Cleaning & Painting
- Hull Air Lubrication Systems
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Source: Marine Insight