> ## Documentation Index
> Fetch the complete documentation index at: https://docs.appliedaifoundation.org/llms.txt
> Use this file to discover all available pages before exploring further.

# EU ETS coverage

> Port classification, voyage segmentation, and per-leg coverage logic.

The EU ETS engine in `src/lib/utils/portClassifier.ts` and `src/lib/services/VoyageSegmentService.ts` produces per-leg covered CO₂ figures used everywhere in the app — fleet ETS dashboard, vessel detail voyages table, EU ETS report.

## Port classification

A port is classified **EU/EEA** if its UN/LOCODE country code (the first two letters) matches one of these 30 codes:

```
EU members:
AT BE BG HR CY CZ DK EE FI FR DE GR HU IE IT
LV LT LU MT NL PL PT RO SK SI ES SE

EEA members (non-EU):
IS LI NO
```

Anything else is non-EU.

## Voyage type from leg endpoints

| Departure | Arrival | Voyage type |
| --------- | ------- | ----------- |
| EU/EEA    | EU/EEA  | INTRA\_EU   |
| Non-EU    | EU/EEA  | INTO\_EU    |
| EU/EEA    | Non-EU  | OUT\_OF\_EU |
| Non-EU    | Non-EU  | NON\_EU     |

## Coverage factors

Applied only to **emissions at sea** during the leg:

| Voyage type | Sea coverage |
| ----------- | ------------ |
| INTRA\_EU   | 100%         |
| INTO\_EU    | 50%          |
| OUT\_OF\_EU | 50%          |
| NON\_EU     | 0%           |

## Port emissions: per-record classification

Emissions while **at port** are not tied to the voyage type. They're classified by the actual port LOCODE on each record:

* EU port → 100% covered
* Non-EU port → 0% covered

This matters for multi-port voyages. Example: a voyage Rotterdam → Hamburg → Le Havre → Singapore has three intra-EU legs (100%) followed by an out-of-EU leg (50%). Time spent at the Hamburg and Le Havre intermediate stops is 100% covered; time at Singapore is 0%.

## Phase-in factor by year

| Year             | Phase-in |
| ---------------- | -------- |
| 2023 and earlier | 0%       |
| 2024             | 40%      |
| 2025             | 70%      |
| 2026 onwards     | 100%     |

## Final formula

```
Covered CO₂ (per leg) = (Sea CO₂ × Sea Coverage) + (EU-Port CO₂ × 1.0)
ETS Emissions          = Σ Covered CO₂ (across legs) × Phase-In Factor
ETS Cost (€)           = ETS Emissions × EUA Price
```

EUA price defaults to **€75/tonne** unless overridden via `DEFAULT_EUA_PRICE`.

## Voyage segmentation (BOSP-based)

The `extractVoyageLegs()` function walks consumption records chronologically and creates a new leg whenever it encounters a `BOSP` (Beginning of Sea Passage) event. Records before the first BOSP are buffered and attached to the first leg.

This means:

* A voyage with 4 BOSP events produces 4 legs
* Repeated voyage numbers (e.g. `99W, 99E, 99W`) are split into segments (`99W-1`, `99E-1`, `99W-2`)
* Coverage is applied per leg, not per voyage

## Implementation

* `src/lib/utils/portClassifier.ts` — `isEUPort`, `determineVoyageType`, `getETSCoverageFactor`, `getETSPhaseInFactor`, `extractVoyageLegs`, `calculateLegsETSEmissions`
* `src/lib/services/VoyageSegmentService.ts` — orchestration layer used across pages and reports

## Reference

* [Directive 2003/87/EC (consolidated)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02003L0087-20240101) — EU ETS directive
* [Directive (EU) 2023/959](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32023L0959) — Amendment bringing maritime into ETS
* [Regulation (EU) 2015/757 (consolidated)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02015R0757-20240101) — MRV (data feed)
* [DNV — EU ETS Maritime overview](https://www.dnv.com/maritime/insights/topics/eu-emissions-trading-system-ets/)
* [CE Delft technical report](https://cedelft.eu/publications/eu-ets-and-fueleu-maritime/)