Carbon Intensity Indicator:
Carbon Intensity Indicator (CII) or Carbon intensity indicator is an in-service/operational efficiency indicator that measures a vessel’s carbon intensity over time. The CII regulates the operational or real life of CO2 emissions from ships. It is based on the annual fuel oil consumption, and from 1st January 2023, all ships will have to report their CII each year based on their actual fuel oil consumption. The CII requirements will take effect from 2023 for all cargo, RoPax, and cruise vessels above 5,000 GT trading internationally. The CII helps measure how efficiently the ships transport goods or passengers. Its value is given in grams of CO2 emitted per cargo-carrying capacity and nautical mile.
At the end of the year, the ship is given an annual rating ranging from A to E, A being good, and E requires changes in the plat to achieve a better rating. The rating thresholds will become increasingly stringent towards 2030. While the EEXI is a one-time certification based on the technical measures and targeting design parameters, the CII addresses the actual emissions and is implemented while the ship is in operation.
Calculation of CII
A ship’s CII is calculated as the ratio of the total mass of CO2 emitted to the entire transport work undertaken in a calendar year. A vessel’s performance rating is determined by comparing a ship’s operational carbon intensity performance with the average performance of others ships of the same type.
CII = Co2 Emission / (Dead weight X Distance Sailed)
Responsibility for CII
Ship managers or operators must decide on ships’ carbon intensity profiles and create an optimized Ship Energy Efficiency Management Plan (SEEMP) by the end of 2022. Other options for technical and operational improvements are to be considered, which may include – switching to low-carbon fuels, limiting engine loads, reducing speed, retrofitting vessels with energy-efficient technology, etc. The essential purpose of the EEXI and CII is to create a mindset among maritime industry stakeholders to focus on the ongoing improvements to drive down onboard carbon emissions.
What is a CO2 reduction rating?
Similar to Required and Attained EEDI, we have Required and Attained CII. Whatever CII value the ship will attain at the end of 2023 in comparison with 2019 data, it will be rated annually from A to E, where A is the best rating and E will be considered unacceptable, and the SEEMP III needs revision and improvement. C rating in the chart is the acceptable mark and the required minimum rating. The required CII, and thereby the rating thresholds, will be reduced yearly. The reduction rates are set for 2023 to 2026, and subsequent reduction factors will be set during a review in 2025.
- A – Major superior
- B – Minor superior
- C – Moderate
- D – Minor inferior
- E – Inferior performance
CII rating improvement method
Actual fuel consumption is used to calculate the CII rating evaluation. Reducing fuel consumption per transport distance will improve the CII rating. To improve fuel consumption efficiency following methods can be used.
Improvement method:
- Slow steaming
- Slide type fuel v/v use (Improve Spray & Combustion condition under 40% load)
- Eco nozzle use (atomizer design)
- Eco com (increasing cylinder pressure under 60% load)
- E-VIT (increasing cylinder pressure under 75% load)
- Engine derating (MCO derating) (MCO : Manufacturer’s Certificate of Origin)
- Low load optimization tuning (Optimizing the Engine performance in Low Load Range)
Deterioration suppression method:
- Chief load limiter (Rough Weather- Limit the M/E Load)
- ASR (rough sea auto speed reduction)
- ALC (auto engine load control when hull resistance increase)
- Adaptive sea condition control governor (Automatic Control mood according to Sea Condition)
- PMI auto tuning (Online PMI) (Automatic CyI pressure Measurement / Controlling Function) (PMI : Performance Measurement Indicator)
