Carbon Intensity Indicator (CII)
CII is an operational efficiency indicator that measures a vessel’s carbon intensity over time. It regulates the real-life CO2 emissions from ships and applies to cargo, RoPax, and cruise vessels above 5,000 GT trading internationally from January 1, 2023[1].Key Features
- Measures CO2 emissions in grams per cargo-carrying capacity and nautical mile
- Annual reporting based on actual fuel consumption
- Ships receive an annual rating from A (best) to E (worst)
- Rating thresholds become increasingly stringent towards 2030
CII Calculation
The formula for CII is:CII = CO2 Emission / (Dead weight × Distance Sailed)CII Ratings
| Rating | Performance Level |
|---|---|
| A | Major superior |
| B | Minor superior |
| C | Moderate |
| D | Minor inferior |
| E | Inferior |
Methods to Improve CII Rating
Improvement Methods
- Slow steaming
- Using slide type fuel valves
- Implementing eco nozzles
- Engine derating
- Low load optimization tuning
Deterioration Suppression Methods
- Chief load limiter
- Auto speed reduction in rough seas
- Auto engine load control
- Adaptive sea condition control governor
- PMI auto tuning
