Formula
Credit subtracted from the EEDI numerator:
$$ \text{Credit} = f_\text{eff} \cdot P_\text{eff} \cdot C_{f,\text{ME}} \cdot \text{SFC}_\text{ME} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $Credit$ | Numerator subtraction | g CO₂ / h | result |
| $f_\text{eff}$ | Availability factor | - | MEPC.1/Circ.815 |
| $P_\text{eff}$ | Effective saved power | kW | tech spec |
| $C_{f,\text{ME}}$ | Main-engine fuel CO₂ factor | t CO₂ / t | MEPC.364(79) |
| $\text{SFC}_\text{ME}$ | Main-engine SFC | g/kWh | NOx Technical File |
Categories
- A - reduces auxiliary energy (model by lowering $P_\text{AE}$).
- B - generates electricity (shaft gen, WHR).
- C - reduces propulsion power (wind, air lube); apply $f_\text{eff}$ availability.
Sources
- IMO MEPC.1/Circ.815.
- IMO MEPC.328(76).