EPL - Engine Power Limitation for EEXI
Compute the main-engine MCR reduction needed to move an existing ship from its pre-limitation Attained EEXI down to the Required EEXI - the cheapest route to compliance for many operators.
Pre-limitation values
Minimum power reduction
45.6%
Limit MCR to 54.4 % of nameplate.
Limited MCR
4,082kW
Limited 75 % MCR
3,062kW
Formula, assumptions, and limits
Power ratio = (Required / Attained_before)^(3/2) Reduction % = 1 − ratio Limited MCR = ratio × nameplate MCR
Derivation: Attained EEXI ∝ numerator / V_ref, numerator ∝ P (linear), V_ref ∝ P^(1/3). So scaling P by factor k scales attained by k^(2/3). Solve k^(2/3) = Required/Attained_before to get k = (Required/Attained_before)^(3/2).
Real-world override: 15 % is a common minimum EPL reduction that many classification societies accept without additional studies. Check with your flag state and class society before installing.