How to improve tanker CII scores with verified fuel reporting

With the tanker industry navigating regulations like the Carbon Intensity Indicator (CII), EU Emissions Trading System (ETS), and FuelEU Maritime, the need for trustworthy and accurate fuel consumption reporting has never been more important.

For shipowners, this means managing the risk of non-compliance and maintaining a positive CII rating. For charterers, it is about having reliable data to settle voyage costs and avoid commercial disputes. For operators, it involves the daily challenge of collecting and correcting data accurately.

This shared challenge requires a collaborative solution. An approach that moves beyond simple data collection to create a single source of truth that everyone can trust. Through a partnership between ZeroNorth and DNV, we can help address this challenge by integrating technology and accredited third-party verification into one clear workflow. This guide explores the challenges of modern fuel reporting and how a verified, collaborative approach can help operators build confidence and find value in their data.

Understanding sub-consumers: the foundation of quality data

To build a true picture of a vessel's performance, we first need to understand all the ways it consumes fuel. In tanker operations, this goes far beyond the main engine. Sub-consumers are auxiliary systems that play a vital role in the vessel's overall fuel profile, sometimes accounting for a substantial portion of total fuel use. Accurately tracking their consumption is the first step towards granular, verifiable reporting.

Key sub-consumers on tankers typically include:

• Cargo heating: Many cargoes, like certain oil products, must be kept at specific temperatures throughout a voyage. The heating systems used for this are significant fuel consumers.
• Cargo transfer: During port operations, the large pumps used for loading and unloading cargo are major consumers of fuel.
• Inert gas systems: These safety-critical systems maintain a safe atmosphere in the cargo tanks and require fuel to operate.
• Auxiliary boilers: Boilers provide steam for various needs, including cargo heating, heating heavy fuel oil for the main engine, and providing hot water for crew accommodation.
• Generators: These provide the vessel's electrical power for lighting, navigation systems, and all other onboard equipment, especially when the main engine is not running.
• Ballast water treatment systems: A regulatory requirement for environmental compliance, these systems also consume fuel during their operation.

By recognising the importance of these sub-consumers, operators can begin to capture the detailed data that forms the foundation of a high-quality, verifiable emissions profile. This detailed understanding allows for more precise emissions reporting and opens up new opportunities for targeted efficiency improvements.

CII calculations: why a multi-layered verification process is essential

The Carbon Intensity Indicator (CII) has become a key metric for assessing a vessel's operational efficiency. While the formula is straightforward, its power lies in the credibility of the underlying data.

A vessel’s CII score can be influenced by several factors, including voyage efficiency, speed optimisation, weather conditions, and vessel maintenance. However, the foundational element is the fuel consumption data itself. For this data to be accepted by regulators and commercial partners, it must be defensible. This is why a multi-layered validation process is so important. Through the ZeroNorth and DNV partnership, data undergoes a rigorous journey:

1. First-layer validation (onboard): The ZeroNorth platform performs hundreds of automated, real-time checks as crew enter data, preventing common errors at the source.
2. Second-layer validation (ashore): ZeroNorth’s dedicated Data Quality Team conducts a deeper, human-in-the-loop validation, checking for contextual issues and logical inconsistencies.
3. Third-layer verification (accredited): The data is automatically sent to DNV’s Data Workbench and Emissions Connect platform. Here, it undergoes a final layer of validation where DNV’s trusted systems check it for compliance with official regulations like EU MRV and IMO DCS.

This end-to-end process helps ensure the final CII score is not just a calculation, but a verified, trusted, and compliant metric that can withstand scrutiny.

What verified data means for your operations

Accurate fuel allocation is the key to a fair CII score, but verified allocation is what builds commercial trust and regulatory confidence.

By having granular fuel consumption data validated by an independent body like DNV, operators can more confidently report on fuel used for essential operations like cargo heating. This can lead to a fairer CII assessment and potentially an improved rating. For charterers, DNV-verified data helps to reduce disputes over emissions costs and provides a trusted, neutral foundation for settling EUAs or other FuelEU-related costs. This transforms data from a potential point of conflict into a tool that supports partnership.

A major challenge in reporting is the inefficient, fragmented correction process. This collaborative workflow helps to streamline corrections. Any issue flagged by DNV is automatically routed back to the ZeroNorth Data Quality Team. They then provide the vessel’s Master with a single, clear list of required corrections, helping to remove confusion and speed up resolution.

Addressing the practical challenges of granular reporting

Moving towards more detailed reporting methods, such as tracking consumption from individual fuel tanks, introduces new practical considerations for the crew. This method involves documenting consumption from each tank, recording any transfers between them, and reporting on the final volumes. While this approach offers more precise data, it also increases the workload and potential for human error on board.

This is where technology and training become essential partners. An intuitive digital platform can automate much of this tracking, reducing the manual burden on crews. However, technology alone is not the entire solution. Empowering the crew with the knowledge and support they need is fundamental to a successful transition.

Effective training programs are vital for ensuring data accuracy and efficiency. Training should focus on helping the crew understand not just how to use new tools, but why detailed reporting is so important for the vessel's compliance and commercial success. Key areas of focus should include understanding sub-consumers, procedures for new data entry, and a basic knowledge of how their efforts impact metrics like CII.

Overcoming resistance to change is best handled with a collaborative spirit. By clearly communicating the reasons for new procedures, introducing changes in manageable phases, and providing continuous support, operators and technology partners can ensure crews feel equipped and valued throughout the process.

The challenge of evolving fuels and regulations

The introduction of new fuel types, such as biofuels, adds another layer of complexity. Operators must now accurately track not just the quantity but also the specific blend ratios and characteristics of these fuels to ensure compliance with emerging regulations like FuelEU Maritime.

These new fuels have different energy densities and emissions factors, which must be correctly applied in all calculations. A robust and flexible reporting system is needed to handle this complexity. The system must not only capture the data but also support its validation against the specific rules governing these new fuels, ensuring that operators can confidently adopt cleaner energy sources without creating compliance risks.

The role of technology in enabling verified reporting

Technology is the foundation that makes this new standard of reporting possible. Advanced platforms like ZeroNorth do more than just simplify data entry; they serve as the integrated pipeline for a complete verification workflow.

The system is designed to automate the secure flow of data from the vessel to ZeroNorth’s validation teams and then onward to DNV's verification platform. This integration provides the structure for a process built on data integrity, from the ship to the shore and to the verifier. By leveraging cloud-based software, data analytics, and a robust, multi-layered validation structure, this partnership tackles the core industry challenges of complexity and a lack of trust in data.

Looking ahead: the future is collaborative

As we look to the future of fuel reporting, it is clear that the focus is shifting from simple accuracy to verifiability. The collaboration between ZeroNorth and DNV shows that the answer to shipping's significant data challenges often lies in partnership—combining innovative technology with trusted, world-leading verification.

This approach offers benefits for everyone involved:

• For owners and operators: It provides confidence in compliance, helping to reduce the risk of financial penalties.
• For charterers: It builds commercial trust and simplifies settlements by providing a single, verified dataset.
• For the industry: It creates a pathway to leverage trusted data for wider strategic goals, such as ESG reporting and securing green finance.

By embracing a collaborative, multi-layered approach to data, we can help turn the complex task of reporting into a strategic asset that supports efficiency, ensures compliance, and fosters a more transparent and sustainable maritime industry.