Estimation and Optimization of Ship Fuel Consumption in Maritime: Review, Challenges and Future Directions
Organizations: Simula Research Laboratory, Kristian Augusts 23, Oslo, 0164, Norway
Abstract
To reduce carbon emissions and minimize shipping costs, improving the fuel efficiency of ships is crucial. Various measures are taken to reduce the total fuel consumption of ships, including optimizing vessel parameters and selecting routes with the lowest fuel consumption. Different estimation methods are proposed for predicting fuel consumption, while various optimization methods are proposed to minimize fuel oil consumption. This paper provides a comprehensive review of methods for estimating and optimizing fuel oil consumption in maritime transport. Our novel contributions include categorizing fuel oil consumption & estimation methods into physics-based, machine-learning, and hybrid models, exploring their strengths and limitations. Furthermore, we highlight the importance of data fusion techniques, which combine AIS, onboard sensors, and meteorological data to enhance accuracy. We make the first attempt to discuss the emerging role of Explainable AI in enhancing model transparency for decision-making. Uniquely, key challenges, including data quality, availability, and the need for real-time optimization, are identified, and future research directions are proposed to address these gaps, with a focus on hybrid models, real-time optimization, and the standardization of datasets.
Figures & tables
| Papers | FOC Est. | FOC Opt. | FOC-XAI | Feature Discussion | Challenges | Data Fusion |
| Fan et al. (2022b) | ✓ | ✓ | ||||
| Wang et al. (2022) | ✓ | |||||
| Barreiro et al. (2022) | ||||||
| Mylonopoulos et al. (2023) | ✓ | ✓ | ||||
| Yan et al. (2021b) | ✓ | ✓ | ✓ | ✓ | ||
| Our work | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Nomenclature | Meaning |
|---|---|
| AIS | Automatic Identification System |
| AES | All-electric ship |
| ANN | Artificial Neural Network |
| BBM | Black Box Model |
| COG | Course Over Ground |
| CMEMS | Copernicus Marine Environment Monitoring Service |
| Data Type | Example Sources | Key Features |
| Navigation Data | AIS, Noon Reports | speed, draft, trim |
| Engine Data | Onboard Sensors | rpm, power output, fuel flow |
| Meteorological Data | ECMWF, NOAA, CMEMS | wind, waves, sea currents |
| Regulatory Data | MRV, IMO DCS | reported emissions, compliance metrics |
| Source | Engine | Navigation | Metocean | FOC and GHG Emissions |
| AIS | SOG, COG, draft | |||
| Noon Reports | average propeller rpm, average engine rpm | draft, trim, average SOG, COG | wind magnitude and direction, sea conditions and sea swell | Fuel oil consumption (FOC), daily consumption |
| Onboard Sensors | rpm, engine power, torque, engine temperature | SOG, COG | wind magnitude and direction, sea waves | FOC (if fuel sensors are installed) |
| Online Sources | sea water temperature, wind direction, wind magnitude, wave direction, wave height, sea current direction, sea current speed | |||
| MRV | FOC, CO 2 emissions |
| Data Source | Example Providers | Typical Features | Resolution / Access | Advantages and Limitations |
| AIS | MarineTraffic, EMSA | SOG, COG, position, draft, ETA | Sec–min; public | Standardized and global coverage; lacks direct engine/fuel data; possible signal gaps and spoofing; timestamps may need resampling. |
| Noon Reports | Ship logbooks | Avg. speed, RPM, draft, trim, FOC | Daily; internal | Contains direct daily FOC; coarse granularity and subject to manual entry noise; limited for short-term/real-time analysis. |
| Onboard Sensors | ECU, shaft/fuel meters | RPM, torque, shaft power, fuel flow, temp/pressure | Seconds; proprietary | High fidelity and suitable for real-time modeling; access restricted by confidentiality; sensor drift and calibration needed. |
| Online Sources | ECMWF, NOAA, CMEMS | Wind, wave, current, SST, pressure | Hour–daily; open | Essential for weather routing and exogenous features; spatial/temporal mismatch with vessel tracks; interpolation and co-location required. |
| MRV | EMSA (EU MRV) | Annual FOC, CO 2 , vessel data | Annual; public (EU) | Regulatory-grade, standardized aggregates; low temporal resolution limits operational analytics; useful as benchmarking/validation. |
| Papers | Noon Reports | MetOcean | MRV | AIS | Sensors |
| Li et al. (2022) , Hajli et al. (2024) , Luo et al. (2023b) | ✓ | ✓ | |||
| Zhou et al. (2023) | ✓ | ✓ | |||
| Du et al. (2022b) ; Yan et al. (2024) | ✓ | ✓ | ✓ | ||
| Du et al. (2022c) | ✓ | ✓ | |||
| Ren et al. (2022) , Wang et al. (2023c) | ✓ | ✓ | ✓ | ||
| Farag and Ölçer (2020) ; Zhang et al. (2023b) | ✓ | ✓ | ✓ |
| Paper | Output | Features Included | Method Type | Results |
| Hajli et al. (2024) | Metric ton per nautical mile | rpm, sog, slip, wind factor, averaged wind factor, wave factor, averaged wave factor, current factor, averaged current factor | multiple linear regression | MAE: , RMSE: (metric tons per nautical mile) |
| Du et al. (2019) | Metric ton per day | Speed, displacement, wave height, wave direction, wind force, current speed, current direction, sea water temperature, trim | ANN | RMSE of less than 9.5 MT/day |
| Papandreou and Ziakopoulos (2022) | FOC (main engine) [tn] | Speed through water, Relative wind direction, Relative wind speed, Mean draft, Trim, Days since last drydock, Laden or Ballast (binary format) | XGBoost | prediction error with 5% |
| Yan et al. (2024) | Hourly average ME fuel consumption rate | average sailing speed, sailing condition (laden/ballast), wind direction, wind force, draft, air density over the oceans, forecast surface roughness, mean sea level pressure, mean direction of total wave, mean period of total wave, significant height of the total wave, temperature of water near sea surface | ANN | MAE of 7.5% |
| Uyanık et al. (2020) | FOC (ton/day) | M/E fuel oil inlet pressure (bar), temperature (°C), viscosity (cSt), Air coolers cooling water temperature (°C), Jacket cooling water inlet pressure (bar) and temperature (°C), Scavenging air receiver temperature (°C), Bearing temperatures (°C), Start air inlet pressure (bar), Fuel mass flow (kg/h), Shaft power (kW), rpm, torque (kNm), M/E lubrication oil temperature (°C) and pressure (bar), M/E fuel flow counter, M/E power, Exhaust temperature of the cylinders (°C), Turbocharger rpm and exhaust gas inlet temperature (°C). | Bayesian ridge regression, Kernel ridge regression, Multiple linear regression and Ridge regression | Bayesian Ridge (RMSE=0.0001 MAE=0.003 =99.999%), Multiple LR & Ridge (RMSE=0.0001 MAE=0.002 =99.999%), Kernel Ridge (RMSE=0.0001 MAE=0.003 =99.999%) |
| Fan et al. (2024) | ME FOC (kg/h) | Wind speed/direction, water depth, speed (over ground/water), engine fuel use/power, propeller speed/power, bearing temp, exhaust temp/pressure, intercooler air temp, cylinder liner water temp, fuel pressure/temp, and exhaust temp after vortex. | Random Forest and Extreme Gradient Boosting | RF ( =0.9747, MAE=1.72) |
| Papers | Engine Data | Weather/Ocean Data | Operational Data | ML Method | Tree-based |
| Hajli et al. (2024) | ✓ | ✓ | |||
| Du et al. (2019) | ✓ | ✓ | ✓ | ||
| Papandreou and Ziakopoulos (2022) | ✓ | ✓ | ✓ | ✓ | |
| Yan et al. (2024) | ✓ | ✓ | ✓ | ||
| Uyanık et al. (2020) | ✓ | ✓ | ✓ | ✓ | |
| Fan et al. (2024) | ✓ | ✓ | ✓ | ✓ | ✓ |
| Paper | GBM Type | Physics-Based Role | ML Role | Key Advantage | Weaknesses |
| [1] | Serial (S-GBM) | Input for ML model | Corrects residual errors | Balances accuracy & interpretability | Performance depends on quality of the physics-based model; limited adaptability if underlying physics is inaccurate. |
| [2] | Constraint (C-GBM) | Encodes physical laws as constraints during ML training | Learns within physics-informed boundaries | Ensures physically valid outputs | Requires careful formulation of constraints; may restrict flexibility and increase training complexity. |
| [3] | Embedding (E-GBM) | Embeds physics components directly in ML architecture | Replaces computationally expensive physics solvers | Enables fast, real-time estimation | Implementation is complex; may lose interpretability and risk overfitting without sufficient physical guidance. |
| Paper | XAI Method | Interpretability | Accuracy | Key Trade-Off |
| [1] | SHAP | High | Moderate | Loss of some model flexibility |
| [2] | PI-NN & MIO | PI-NN: Moderate, MIO: High | PI-NN: High, MIO: Moderate | MIO is highly interpretable but less accurate |
| [3] | SHAP + XGBoost | High | High (R² = 0.95) | Computational overhead due to SHAP analysis |
| [4] | SHAP + XGBoost | High | Very High (R² = 0.99) | Model sensitivity to different load conditions |