Operational Guide · Registers & Logbooks

# EEXI and Engine Power Limitation (EPL)

A technical index calculated only once, but that permanently constrains the maximum available power: the most common route to compliance is limiting the engine, not modifying it.

EEXI EPL energy efficiency MARPOL Annex VI

## Operational Explanation

The Energy Efficiency Existing Ship Index (EEXI) is a technical index, calculated only once, that measures the design energy efficiency of an existing ship, conceptually similar to the EEDI required for new construction. In force since 2023, it requires every ship to pass verification against a reference value specific to its type and size.

By far the most common measure for achieving EEXI compliance is Engine Power Limitation (EPL): limiting the maximum available power of the main engine, which directly reduces the calculated index value by lowering the maximum attainable speed and theoretical energy consumption, without requiring invasive technical work on the engine itself.

## Regulatory Reference

MARPOL Annex VI, Chapter 4 (Regulation 23): EEXI is verified only once, typically at the first useful periodic survey following entry into force (2023), with issuance of the updated International Energy Efficiency Certificate.

## Scope of Application

Existing ships subject to MARPOL Annex VI Chapter 4, according to the applicable size and type thresholds (generally cargo and passenger ships above a minimum tonnage).

## Procedure / How to Complete It

1. Calculate the ship's EEXI according to the formula applicable to its type and size, comparing it against the required reference value.
2. If the calculated EEXI exceeds the required value, assess the available compliance measures: EPL, engine derating, or technical efficiency measures (e.g. energy-saving devices).
3. If EPL is chosen, install the approved limitation device (sealable and verifiable), documenting the maximum permitted power.
4. Verify that the limiter cannot easily be bypassed or removed without authorization and a new verification.
5. Obtain verification and endorsement of the updated International Energy Efficiency (IEE) Certificate from the Classification Society.

## Practical Example

Application example: a cargo ship with a calculated EEXI above the required limit, brought into compliance via EPL limiting maximum available power to 82% of the original rated power, with the limitation device sealed and verified by the surveyor.

## Real Cases

The widespread adoption of EPL as the simplest and cheapest compliance measure has raised, according to several industry analyses, concerns about its long-term effectiveness for actually reducing emissions: being a passive measure that does not change the ship's intrinsic efficiency, it is not by itself sufficient to maintain a good CII rating over time, given the increasingly demanding reduction requirements year after year.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Exclusive reliance on EPL without considering the operational impact on maximum available speed | Reduced commercial flexibility of the ship not fully assessed in advance | Assess the operational impact of EPL together with the commercial department before choosing this measure
Limitation device not adequately sealed or verifiable | Risk of unauthorized bypass, resulting in silent non-compliance | Always install a certified limitation device that is sealable and verifiable by the surveyor
EEXI treated as an isolated obligation, disconnected from the long-term CII strategy | EEXI compliance alone does not guarantee a good CII rating in subsequent years, given the increasing severity of the required reduction factors | Integrate the EEXI/EPL strategy with medium/long-term CII/SEEMP planning

## PSC Observations

PSCOs check for the presence and validity of the updated International Energy Efficiency Certificate reflecting EEXI; the presence and integrity of the power limitation device, if used as a compliance measure, may be subject to direct inspection.

## Operational Tips

- Always assess the operational impact of EPL with the commercial department before adopting it as a compliance measure.
- Make sure the limitation device is certified, sealable and verifiable, not an improvised solution.
- Do not treat EEXI as an isolated obligation: always link it to the long-term CII strategy.

## Checklist

- EEXI calculated according to the applicable formula and compared against the reference value
- Chosen compliance measure (EPL or other) also assessed for operational impact
- Limitation device, if used, certified and sealable
- IEE Certificate updated and verified by the Classification Society
- EEXI strategy integrated with long-term CII/SEEMP planning

## FAQ

What is Engine Power Limitation (EPL)?
It is the most common EEXI compliance measure: it limits the maximum available power of the main engine via a certified device, reducing the calculated index value without requiring invasive technical work on the engine.
Must EEXI be recalculated periodically?
No: unlike CII (calculated and assessed annually), EEXI is verified only once, unless significant modifications to the ship alter its calculation (e.g. an engine change or a change in the efficiency measures adopted).
Is EPL alone sufficient to guarantee a good CII rating in subsequent years?
Not necessarily: being a passive measure that reduces available power but not the ship's intrinsic efficiency, it may not be sufficient against the increasing CII reduction factors required year after year (11% in 2026 versus 2019, rising to 21.5% by 2030).
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

CII (Carbon Intensity Indicator)MARPOL Annex VI — Prevention of Air Pollution

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