Environmental Ship Index from NOx, SOx, CO₂ and OPS capability - major ports give port-due discounts for high ESI.
Formula
$$ ESI = S_{NOx} + S_{SOx} + S_{CO_2} + S_{OPS} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $ESI$ | Environmental Ship Index | - | IAPH ESI |
Sources
- IAPH Environmental Ship Index.