EEOI
EEOI (Energy Efficiency Operational Indicator) measures CO₂ per transport work — i.e. per unit of cargo actually moved per nautical mile. Unlike CII, which uses a ship’s design capacity in the denominator, EEOI uses what the ship is actually carrying.
Two flavours
The vessel detail page shows EEOI in two units, depending on ship type:
EEOI by TEU (containers)
EEOI_TEU = Total CO₂ (g) / (TEU carried × Distance NM)Reported in gCO₂ / TEU-NM. Used for container ships where cargo is volumetric.
EEOI by weight (bulk and general cargo)
EEOI_W = Total CO₂ (g) / (Cargo weight (t) × Distance NM)Reported in gCO₂ / tonne-NM. Used for bulkers, tankers, and general cargo where cargo is mass-based.
Why both?
Container vessels report cargo in TEU; bulkers in tonnes. A single weight-based EEOI doesn’t make commercial sense for containers (a TEU of feathers and a TEU of bricks are very different). Showing both lets the dashboard work for any fleet mix.
Supporting figures
Alongside the EEOI numbers, the vessel detail page shows:
- Transport work — TEU-NM or T-NM
- Total CO₂ — tonnes
- Total distance — NM
- Average cargo per voyage — TEU or tonnes
These let you sanity-check the input ratio.
Implementation
EEOI is computed in the vessel detail client component using fields from the consumption log: cargoWeightT, cargoTeu, distanceOverGroundNm, totalCo2T. There’s no separate calculator file — it’s a straightforward division with type-aware unit choice.
Relationship to CII
| CII | EEOI | |
|---|---|---|
| Denominator | Capacity (DWT/GT) — design | Cargo carried (TEU or t) — actual |
| Used for | Compliance rating (A–E) | Operational efficiency tracking |
| Regulator | IMO | Industry standard (not regulated) |
| When more useful | Year-end compliance | Voyage-by-voyage efficiency |
EEOI is not a regulatory metric — it’s an operational benchmark that sits alongside CII. The platform shows both because they answer different questions.
Reference
- IMO MEPC.1/Circ.684 — Guidelines for Voluntary Use of EEOI