Accurate fuel measurement is crucial for effective emissions monitoring and compliance. While onboard sensors provide valuable data, relying on them alone can lead to inconsistencies. This Article explores why sensors must be part of a broader, integrated system, and the importance of regular maintenance and calibration for ensuring reliable fuel measurement.
Reliable Fuel Measurement Systems: Why Sensors Alone Are Not Enough
A multitude of systems exist onboard ships that collect and process data to generate insight into ship performance. Some of these include the Coriolis metre, fuel tank monitoring systems, fuel management systems, and many others.
A common misunderstanding is that sensors and other fuel measurement systems alone will produce accurate emissions data. This is not the case. Even advanced, high-accuracy sensors contribute some level of uncertainty. Combine this with the likelihood of human error and other unforeseen variables, and the risk of inconsistent emissions data is heightened. One industry stakeholder we spoke with likened having sensors without a data analytics platform to, “Having an advanced stereo system but only using it to play basic music, missing out on all the cool features.”
Karl Holz, the retired (2018) President of Disney Cruise Lines, has been an advisor to SailPlan since 2022. He explained:
“The need for precise system inputs has driven an assessment of various onboard systems for multiple clients. Validating the accuracy of engineering and other data streams has proven to be a highly detailed and time-consuming process and has resulted in various technology upgrades and other tools, which enable more efficient operation of ships. This is all essential for precise emissions measurement.”
One study examined the uncertainty of ship fuel monitoring across flow metres, bunker delivery notes (BDNs), and bunker fuel tank measurements over a 3.5-year period. It found that there was ±5% uncertainty. On a single voyage, differences of 15-20% between flow meter and tank measurement estimates were observed.
Another industry stakeholder we spoke with said:
“Sensors are like a light switch. They report data, but without an advanced system, the data remains underutilised and difficult to interpret.”
He went on to say that this challenge is often rooted in tradition.
“People are kind of stuck in their ways. Instead of trusting instrumentation that provides real-time data, they still rely on outdated formulas.”
Relying on sensors alone, without a robust data platform for processing and analysis, can lead to overlooked quality and metric issues. To ensure accurate emissions data, advanced sensors must be integrated into a highly functioning and robust broader system that includes analytics for validation and insight generation.
Fueling Accuracy: Why Regular Maintenance & Calibration of Sensors Are Key
Regular maintenance and calibration of fuel measurement systems are fundamental to ensure they maintain accuracy and perform to their full functionality over a long period. Over time, the natural wear and tear of sensors and metres will reduce accuracy.
The risk of a poorly calibrated metre is that it could fail to detect fuel issues in the fuel received. This could lead to companies spending on a specific quantity or quality of fuel only to realise at a later date that it doesn’t match the amount purchased. Regular maintenance and calibration, in alignment with ISO standards, such as ISO 17025, will ensure consistency.
26 IMarEST (Dec, 2014) Further technical and operational measures for enhancing the energy efficiency of international shipping
27 Sun, R et al., (Jan, 2025) A comprehensive analysis of strategies for reducing GHG emissions in maritime ports
For a more detailed understanding and exploration of the topics covered in this article, refer to our report, Transforming Maritime Operations: Unlocking Accurate Data for Sustainability and Compliance, commissioned by SailPlan.
