Python · SciPy · Numerical optimization · FuelEU Maritime · EU ETS · Scenario analysis
Maritime Fuel Optimization began as a team prototype in 2024. It explores how ship operators could compare fuel strategies while accounting for fuel cost, greenhouse-gas intensity, carbon allowance exposure, voyage scope, and onshore power supply (OPS) at berth.
The original experimental repository has been preserved privately. This public case study presents the problem, verified engineering approach, and selected sanitized results without distributing source code, third-party calculators, or regulatory documents.
Fuel choice is not a single-variable decision. A lower-emission fuel can have a higher purchase price, while a conventional fuel may create additional FuelEU or EU ETS exposure. Voyage geography and berth operations change the modeled scope again.
The prototype evaluates those interacting costs as one optimization problem:
flowchart LR
A[Voyage energy profile] --> D[Deterministic optimizer]
B[Fuel and carbon assumptions] --> D
C[FuelEU and EU ETS rules] --> D
D --> E[Fuel-mix recommendation]
D --> F[Cost breakdown]
D --> G[Emissions and compliance indicators]
- Intra-EU and extra-EU voyage energy
- Fuel mass, energy density, and purchase cost
- Well-to-wake greenhouse-gas intensity
- Tank-to-wake CO2 allowance exposure
- FuelEU target milestones from 2025 to 2050
- EU ETS phase-in for maritime emissions
- MDO-at-berth versus OPS scenarios
- HFO, VLSFO, MDO, biodiesel, LNG, and e-methanol assumptions
The cleaned model uses a deterministic multi-start SLSQP optimizer with bounded energy shares and an explicit sum-to-one constraint. It replaced several exploratory scripts and a nondeterministic evolutionary solver.
The completed private implementation includes:
- One portable Python package and command-line interface
- Versioned, human-readable assumptions
- Deterministic scenario generation
- Automated tests for scope, phase-in, cost reconciliation, OPS, and optimizer repeatability
- A reproducible matrix of 40 scenarios across milestone years, berth choices, and fuel configurations
The bundled 2025 profile uses 14.5 million MJ of intra-EU energy, 52 million MJ of extra-EU energy, 14.5 million MJ at berth, a carbon price of €90/tCO2, and no OPS.
| Configuration | Optimized energy mix | Total modeled cost |
|---|---|---|
| VLSFO baseline | 100% VLSFO | €1,504,957 |
| VLSFO + biodiesel | 96.5% VLSFO / 3.5% biodiesel | €1,449,847 |
| LNG | 100% LNG | €1,282,199 |
| E-methanol | 100% e-methanol | €5,005,059 |
| Flexible four-fuel mix | 100% LNG | €1,282,199 |
Within these illustrative prototype assumptions, the flexible scenario was 14.8% lower cost than the VLSFO-only baseline. This is evidence that the model runs and reconciles—not a prediction that LNG is universally optimal.
The sanitized result table is available in
data/2025-scenario-summary.csv.
- Regulatory scope and phase-in rules should be explicit model inputs, not scattered constants.
- Determinism matters when comparing scenario outputs or presenting results.
- Lifecycle intensity and direct-emission factors answer different questions and should remain separate.
- A technically plausible optimization can still be misleading if fuel prices, eligibility, and regulatory exclusions are not carefully sourced.
This is a research and portfolio prototype—not regulatory, legal, engineering, financial, procurement, or operational advice.
- Fuel prices and lifecycle factors are illustrative 2024 prototype inputs.
- Methane and nitrous oxide ETS exposure from 2026 is not modeled.
- Pooling, banking, borrowing, RFNBO incentives, exemptions, verifier workflows, and ship-specific eligibility are outside scope.
- OPS is simplified as electricity cost with zero onboard emissions; grid lifecycle intensity is not included.
- Real decisions require current attributable data and independent review.
- FuelEU Maritime regulation (EU) 2023/1805
- European Commission: FuelEU Maritime
- European Commission: maritime EU ETS FAQ
This repository is a public portfolio case study. The production source and its historical artifacts remain private. See NOTICE.md for usage terms.