FuelEU Maritime Well-to-Wake Requirements: Compliance and Strategy for Shipping Companies
Author: Jeroen Berger • Publication date:
FuelEU Maritime has been fully in force since January 1, 2025. The European regulation requires seagoing ships of 5,000 GT and above that call at ports in the European Union (EU) or the European Economic Area (EEA) to reduce the greenhouse gas intensity of their onboard energy use in steps. This standard is based on a well-to-wake approach. In addition to EU Member States, the EEA also includes Iceland, Norway and Liechtenstein, which means ports in these three countries fall under the same framework.
By well-to-wake we mean the total chain emissions of energy, both the emissions before bunkering and the emissions during onboard use. This includes well-to-tank, extraction, refining and transport of fuel or electricity, plus tank-to-wake, combustion or use in engines, boilers and systems. The standard expresses this performance in grams of CO2 equivalent per megajoule (g CO2e/MJ), so that each energy carrier is assessed uniformly and verifiably on climate impact per unit of energy delivered.
Where the European Union Emissions Trading System (EU ETS) is a cap-and-trade market that attaches a price to emitted tons of CO2 equivalent through tradable allowances, FuelEU caps emission intensity per megajoule regardless of the fuel type. The reference value is the 2020 fleet average, namely 91.16 g CO2e/MJ. In 2025 a ship must stay at least 2% below that, with a target of 89.34 g CO2e/MJ. This reduction trajectory runs through 2050 with a total required decline of 80%. As a result, steering shifts from purely volume-based emission control to quality control of the energy used.
Because methane (CH4) and nitrous oxide (N2O) also count in the well-to-wake calculation, the focus shifts. It is no longer only about different bunkering, but about an integrated combination of technology and operations. Onshore power supply (OPS) and wind-assisted propulsion play a central role. Targeted fuel choices also contribute, such as Renewable Fuels of Non-Biological Origin (RFNBOs), including e-hydrogen, e-ammonia and e-methanol, and sustainable drop-in fuels such as hydrotreated vegetable oil (HVO) and biomethanol. Depending on the ship type, bio-liquefied natural gas (bio-LNG) or liquefied natural gas (LNG) with low methane slip can also be effective. All these options demonstrably reduce intensity because they favorably influence the denominator in g CO2e/MJ. Shore power is particularly relevant, because by connecting a ship in port to the grid on shore, zero-emission energy is delivered during the port stay and the need to use combustion engines on board lapses.
The urgency is high, because FuelEU is a pillar of the European Green Deal and part of the Fit-for-55 package. That package aims to reduce net EU emissions by at least 55% by 2030 compared to 1990. FuelEU makes a sector-specific contribution by setting binding intensity limits in maritime shipping, accelerating the market for clean energy carriers and anchoring the roll-out of shore power. RFNBOs, as described above, are important in this because they directly contribute to lowering the well-to-wake intensity. The Alternative Fuels Infrastructure Regulation (AFIR) complements this by mandating the roll-out of charging infrastructure, fuel supply and shore power, particularly in Trans-European Transport Network (TEN-T) ports. In this way, FuelEU connects to other building blocks of the Green Deal while making the transition in the maritime chain legally enforceable.
That is why the measurement and reporting chain in the THETIS Monitoring, Reporting and Verification platform (THETIS-MRV) was scaled up in 2024 and from 2025 forms the backbone for compliance calculations. THETIS-MRV is the digital platform managed by the European Maritime Safety Agency (EMSA) on which shipping companies submit voyage data, fuel consumption and OPS hours, verifiers assess this data, and competent authorities exercise oversight. This infrastructure links operational data to a transparent intensity calculation per ship year, so that shipping companies can demonstrably steer their annual intensity and pass audits consistently.
In this article we discuss the scope and objectives of FuelEU Maritime, the well-to-wake methodology in relation to the EU ETS, the implications for technology choices on board and at the quay, the flexibility mechanisms and penalty systems, and the practical steps that shipping companies and shipowners must now take for compliance and investment planning.
What Is FuelEU Maritime and Who Falls Under the Regulation?
FuelEU Maritime applies to all commercial seagoing ships with a gross tonnage of 5,000 GT or more that carry passengers or cargo. This applies regardless of flag state, every ship that calls at a port within the EU or the EEA falls within the legal scope. As mentioned above, Iceland, Norway and Liechtenstein also fall under the same framework.
Outside the scope are ships that do not operate under commercial exploitation or have a specific governmental or special function. This concerns warships and other naval vessels, naval auxiliary vessels, fishing vessels, wooden ships of primitive build, non-mechanically propelled sailing ships, such as tall ships, and government vessels used exclusively for non-commercial purposes. For certain geographic connections a temporary exemption regime applies, liner services to small islands or connections between outermost regions, the most remote regions, such as the Azores, Madeira and the Canary Islands, can be exempted under specific conditions through December 31, 2029. These exemptions safeguard the continuity of local maritime transport infrastructure in areas where sustainable fuels or shore power facilities are not yet operationally deployable.
The weighting, the percentage of energy consumption that counts toward the annual well-to-wake intensity, differs per voyage profile. For intra-EU voyages 100% of the energy used is included. For voyages between EU or EEA ports and a third country or an outermost region, 50% counts. In specific cases, such as certain calls in outermost regions or ports on separate islands, 0% may temporarily count, provided the conditions in the implementing regulation are met.
Ships below the threshold of 5,000 GT fall outside FuelEU and under other regulatory frameworks, such as national or regional emission reduction regimes. For shipping companies with a mixed fleet, it is advisable to include these ships in planning, because they indirectly influence the logistics and fuel supply chains that also serve the FuelEU ships.
The different weightings have direct operational consequences. Shipping companies must align voyage planning, bunkering routes and berths with the weighting of each route category. A nautically identical operation can yield a different energy factor in the FuelEU calculation and thus increase or decrease the annual intensity. It is therefore crucial that technical managers and superintendents model scenarios in advance, including the effects of exemptions, OPS and alternative fuels, so that the fleet not only remains compliant, but also uses the flexibility mechanisms for cost control and investment planning towards 2050.
Reduction Targets and Greenhouse Gas (GHG) Intensity Standards Through 2050
FuelEU Maritime uses a fuel-neutral standard for the average GHG intensity per ship per year. This standard is expressed in grams of CO2 equivalent per megajoule (g CO2e/MJ) and is based on the 2020 fleet average, set at 91.16 g CO2e/MJ according to EU-MRV data. The reduction targets are at least 2% in 2025, target value 89.34 g CO2e/MJ, followed by 6% in 2030, 14.5% in 2035, 31% in 2040, 62% in 2045 and finally 80% in 2050.
The system translates underperformance and overperformance directly into a compliance position. If a ship exceeds the permitted GHG intensity, a negative GHG compliance balance arises with a financial penalty as a result. If the ship performs better than required, this yields surplus units that can be banked indefinitely or deployed via pooling with other ships. This makes planning across multiple reporting years possible.
Although there are touchpoints with IMO instruments such as the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII), FuelEU is stricter. It measures the full well-to-wake emissions, including methane (CH4) and nitrous oxide (N2O), and thus looks beyond tank-to-wake CO2 emissions only. As a result, methane slip and upstream emissions explicitly count, which is particularly relevant for LNG and bio-LNG use.
Against this background, for 2025 through 2030 the emphasis is on no-regret measures. These are actions that are directly implementable, pose low operational risks and demonstrably contribute to reduction. Examples are OPS, wind-assisted propulsion and sustainable drop-in fuels such as HVO or biomethanol.
In 2030 through 2035 the focus shifts to hybrid propulsion concepts and a stronger deployment of RFNBOs, including e-hydrogen, e-ammonia and e-methanol. The expectation is that production and availability in European bunkering networks will increase in these years.
After 2035, carbon-free energy carriers will be guiding for newbuilds and selected retrofits. Feasibility depends on the development of safety frameworks, class standards and port infrastructure. Consider cryogenic storage and fire safety protocols for hydrogen, toxicity management for ammonia and the integration of new engine and fuel systems in ship designs.
This phased approach aligns the rising reduction requirements with practical feasibility in the chain, from fuel production and transport to bunkering logistics, certification and acceptance by classification societies. The result is not only a legal framework, but also a strategic roadmap for fleet modernization towards 2050.
Well-to-Wake: How Is the Full Fuel Chain Calculated?
As explained above, FuelEU Maritime uses the well-to-wake methodology, in which the full chain emissions of energy are included. The default values for these calculations are in Annex II of the regulation and are established as emission factors per fuel type. For LNG-fueled engines an additional factor applies for methane slip. Methane slip is unburned methane that escapes during combustion and has a much higher climate impact than CO2. As long as there is no internationally recognized measurement standard to determine slip accurately, fixed default values must be used. The European Commission is preparing guidance for certification of actually measured slip. Until then, optimization space lies primarily in engine architecture choice and operational settings. This keeps the calculation reproducible and verifiable by verifiers.
In practice, the technical team on board, led by the responsible technical officer, often the chief engineer, records per voyage the fuel consumption by type. They also record the associated lower heating value (LHV). The LHV is the net calorific value of a fuel, the amount of usable energy released upon complete combustion, excluding the latent heat of water vapor in the exhaust gases. This value, usually expressed in megajoules per kilogram or per liter, is essential to determine the energy content that counts in the GHG intensity standard.
They also record the use of OPS or other zero-emission technology, plus any ice conditions that influence energy consumption. Electricity via shore power counts in the numerator with a well-to-tank emission factor of 0 and a tank-to-wake of 0. The delivered energy increases the denominator. As a result, the annual average in g CO2e/MJ demonstrably declines. This makes the direct relationship between port logistics and the ultimate compliance outcome visible.
With LNG propulsion the engine type plays a major role. Low-pressure two-stroke engines and high-pressure four-stroke engines each have their own slip profiles and part-load characteristics, which means the default factor can be conservative in some cases. Because a recognized measurement method is lacking for now, optimization lies mainly in design choices and targeted maintenance. Consider fine-tuning fuel or gas injection nozzles, such as opening time, pressure and spray pattern, optimizing combustion pressure, adjusting gas injection timing and, where technically and safely feasible, applying oxidation catalysts. In this way a shipping company can demonstrably steer toward lower effective methane slip despite the current limitations and thereby improve the well-to-wake intensity.
RFNBOs, Sustainable Biofuels and the Multiplier Scheme
FuelEU Maritime actively promotes the use of Renewable Fuels of Non-Biological Origin (RFNBOs) and sustainable biofuels. RFNBOs are synthetic energy carriers such as e-hydrogen, e-ammonia and e-methanol, produced with renewable electricity and not derived from biomass. To accelerate investments in these fuels, a multiplier scheme applies through December 31, 2033. All RFNBO energy used on board counts double in the GHG compliance balance.
If in 2031 less than 1% of total fleet energy consumption is supplied by RFNBOs, a mandatory sub-target of 2% takes effect from January 1, 2034. This prevents the market introduction of RFNBOs from proceeding too slowly and jeopardizing reduction targets towards 2050.
RFNBOs must meet the sustainability and GHG emission reduction criteria from European renewable energy legislation. The maximum allowed well-to-wake emissions amount to 28.2 g CO2e/MJ. Biofuels and synthetic variants that do not meet these criteria are legally regarded as fossil, with their emission factor equated to the highest fossil reference value. This keeps the system technology neutral, while anchoring sustainability in law.
In day-to-day practice in port and yard this means that shipping companies set up a certificate chain. This usually happens via a chain-of-custody model on a mass-balance basis, in which a validated GHG declaration is provided per fuel batch. This makes it indisputable during verification how much sustainable energy was actually consumed. Contractually it must also be laid down which party, the owner or the charterer, has the right to record the GHG claims in the GHG compliance balance, and how any volume corrections are processed for variations in fuel density or blend ratios.
This documentation aligns with the audit and verification requirements of THETIS-MRV, so that no inconsistencies arise between fuel administration and the reports to verifiers and competent authorities.
OPS in European Ports: Obligations and Exemptions
Article 6 of FuelEU Maritime, in combination with the Alternative Fuels Infrastructure Regulation (AFIR), requires large passenger and container ships to switch to shore power during port stays. This applies from January 1, 2030 in ports covered by Article 9 AFIR. From January 1, 2035 the obligation applies in other EU ports where OPS is available for any passenger or container ship above 5,000 GT.
There are limited exemptions, a port stay shorter than two hours, use of zero-emission technology on board during the stay, emergency or unforeseen stops, or when OPS is not available or technically incompatible. In the intensity calculation, electricity via shore power counts as zero-emission energy in the sense that the numerator is 0, well-to-tank 0 and tank-to-wake 0, while the denominator increases with the energy delivered. As a result, the annual average in g CO2e/MJ demonstrably improves.
Practical implementation requires system compatibility and safety both on board and ashore. High-voltage (HV) OPS according to IEC/IEEE 80005-1 requires on the ship a high-voltage inlet, synchronous voltage control, harmonic filtering and an integrated safety management system with interlocks, grounding control and procedures for blackouts. On shore, grid capacity, peak loads and reservation of connection windows are determining factors.
An early interface check between ship and port installation is essential to avoid invoking technical incompatibility and thus non-compliance. This makes it possible to plan investments in both onboard installations and shore facilities in time and to align implementation in fleet planning and port logistics.
Banking, Borrowing and Pooling: How Do the Flexibility Mechanisms Work?
FuelEU Maritime recognizes that the maritime transition takes time and that investments and operational adjustments do not always align with the annual compliance cycle. That is why the regulation provides three formal flexibility mechanisms, banking, borrowing and pooling.
Banking means that a ship or fleet that performs better than the required GHG intensity may carry the positive GHG compliance balance forward in full to subsequent calendar years. This balance is valid indefinitely and can be used strategically to absorb future peaks in emission intensity.
Borrowing makes it possible, in the event of a shortfall, to borrow part of the surplus from the next year in advance. When paying back, 10% is added as interest in the form of additional reduction obligation. Borrowing is permitted solely for the exact shortfall and lapses once pooling has been applied to prevent double counting.
Pooling gives shipping companies the option to bundle the compliance balances of multiple ships so that surpluses can compensate deficits within the same pool. A ship may participate in only one pool per calendar year. The regulations allow separate pools for the general GHG intensity standard and for the specific RFNBO sub-target. Registration and validation run via one designated verifier, who reviews and certifies the bundled reports.
These mechanisms offer operational room without undermining the annual responsibility of individual ships. Strategically, borrowing in the first years 2025 through 2027 can be used to bridge temporary shortfalls and spread investment peaks. Banking becomes attractive in the period 2028 through 2030 when RFNBO volumes contracted early or substantial OPS hours structurally generate surpluses. Pooling works particularly well within homogeneous fleet clusters with similar voyage routes, fuel profiles and port logistics. In this way the fleet can be optimized as an integrated system while ship-specific compliance remains legally safeguarded.
Penalties, Sanctions and the FuelEU Document of Compliance (DoC)
A negative GHG compliance balance results in a financial sanction. The amount of the penalty is calculated by multiplying the shortfall in megajoules by a fixed reference price of € 2,400 per ton of Very Low Sulphur Fuel Oil (VLSFO) equivalent. Since one ton of VLSFO equals 41,000 MJ, this amounts to approximately € 58 to € 60 per gigajoule.
For ships that fall under the OPS connection obligation but do not switch to shore power in time, a separate penalty regime applies, € 1.50 per kWh, multiplied by the ship’s established total electrical power demand at berth and the number of hours of non-compliance.
The proceeds from these sanctions are earmarked by the EU for further development of sustainable fuels and OPS infrastructure, which means the penalty money flows back into decarbonizing the sector.
After payment of all amounts due, the ship receives a FuelEU Document of Compliance (DoC). This DoC is valid for 18 months after the end of the reporting period, or until issuance of a new DoC.
The consequences go beyond the penalty, a port access ban can lead to disruption of voyage routes, renegotiation or termination of charter contracts and significant extra waiting time or diversion costs. Preventive compliance is therefore the most sensible strategy not only legally, but also operationally and commercially.
Monitoring, Reporting and Verification in THETIS-MRV
FuelEU Maritime builds on the existing EU-MRV system (Monitoring, Reporting and Verification) but has its own monitoring and reporting cycle with strict, legally enforceable deadlines. No later than August 31, 2024, a FuelEU monitoring plan had to be approved by an accredited verifier for each ship within scope. Ships that come within scope later must submit their plan no later than two months after the first call at an EU or EEA port. The monitoring plan aligns in content with the EU-MRV format and contains additional sections on the use of OPS, deployment of zero-emission technology and well-to-wake emissions, including CO2, methane (CH4) and nitrous oxide (N2O). This records all variables for the annual GHG intensity calculation fully traceably and verifiably.
From January 1, 2025, shipping companies and managers record per voyage the fuel consumption by fuel type, the associated LHV, the well-to-wake emissions of CO2, CH4 and N2O, the hours of OPS and zero-emission technology use and any ice conditions that influence energy consumption. No later than January 31, 2026, and annually thereafter, they submit this data via THETIS-MRV to the designated verifier. No later than March 31, 2026, the verifier assesses the FuelEU annual report and records the average GHG intensity, the GHG compliance balance and the number of non-compliant OPS calls.
The company then indicates no later than April 30, 2026 whether it uses banking, borrowing or pooling. At that time it receives the final balance and, where applicable, the amount of the penalty. Penalties are paid no later than June 30, after which the FuelEU DoC is issued. Without a valid DoC, the previously described risk of a port access ban applies.
High information and data quality is crucial. A watertight audit trail requires consistent mass balances, unambiguous LHV values per fuel batch, clear voyage delimitation and verifiable evidence of OPS connections. Effective data governance at fleet level prevents disputes about the origin of reductions, especially when pooling and banking are applied in parallel. This keeps management decisions defensible toward both classification societies and verifiers and minimizes the risk of rejection during audit.
Differences and Interaction Between FuelEU Maritime and the EU ETS
FuelEU Maritime and the EU Emissions Trading System (EU ETS) have the same objective, accelerated decarbonization of shipping, but use different levers. FuelEU caps the greenhouse gas intensity per megajoule of energy delivered and offers flexibility via banking, borrowing and pooling. The EU ETS is a cap-and-trade system in which for every reported ton of CO2, and from 2026 also CH4 and N2O, allowances must be surrendered. The ETS covers 100% of emissions for intra-EU voyages and 50% for voyages to and from third countries. Unlike FuelEU, the ETS has no borrowing or pooling at ship level, but it does have free trading of allowances.
The strategic gain for shipping companies lies in jointly steering both regimes. A low well-to-wake intensity improves the GHG compliance balance, while absolute reduction of fuel consumption directly lowers ETS costs. Combining that dual steering creates financial and legal robustness, particularly with long-term contract positions and investment decisions.
The reporting obligations partially overlap. MRV data form the basis for both the ETS and FuelEU, but a FuelEU monitoring plan contains additional elements, such as records of OPS connections, deployment of zero-emission technology and data on methane slip. The allocation of responsibility also differs. Under the ETS the primary responsibility lies with the registered owner of the ship, unless that has been contractually transferred to the DoC-holder. FuelEU designates the DoC-holder as the responsible entity under the International Safety Management Code.
This difference carries through into contract management. Clauses, insurance coverage and the allocation of operational powers around fuel choice must be aligned to both frameworks. In this way contract management becomes an integral part of compliance, with technical choices, operational planning and legal arrangements connecting seamlessly to reduce risks and preserve strategic room for maneuver.
Technology and Fuel Pathways for Compliance
The choice of fuel and technology largely determines whether ships can meet the stricter well-to-wake standards. Feasibility differs per ship type, voyage profile and operational regime. Strategic decisions therefore require a coherent assessment of technical validation, safety frameworks and security of supply. Those who approach these factors integrally build a robust path towards 2030 and 2050.
Within that approach, LNG and liquefied petroleum gas (LPG) constitute a defensible transition path for certain segments. LNG has a lower CO2 emission factor than conventional oil products, but the benefit is bounded by methane slip, which strongly depends on engine type. As long as international measurement standards are lacking, fixed default values apply. Future European guidance may recognize lower slip values when they are demonstrably measured. For deep sea, LNG, combined with OPS and aero- or hydrodynamic optimizations, can be an interim solution. LPG follows a similar logic, but requires a separate safety and technical assessment due to differing combustion and storage characteristics.
Where LNG and LPG fill an intermediate phase, methanol and e-methanol offer a cleaner combustion profile with virtually no methane slip. RFNBO methanol, produced from green hydrogen and renewable CO2, counts double in the GHG compliance balance through 2033. Retrofit is relatively attractive because modifications to tanks and piping systems remain limited, although an assessment in accordance with the International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code), inerting and care for material compatibility are required. By bundling this work with regular dry-dock periods downtime remains minimal.
At the carbon-free end of the spectrum are ammonia and hydrogen. Provided they are produced renewably, both can deliver low well-to-wake values. Deployment is initially constrained by safety and infrastructure. For ammonia, toxicity and NOx formation play roles. For hydrogen, cryogenic storage and increased flammability risks are relevant. Class acceptance, supported by Hazard Identification (HAZID) and Hazard and Operability (HAZOP), largely determines the project schedule. Careful planning and integrated risk management are decisive for the success of pilots and subsequent scale-up.
In parallel, sustainable biofuels such as HVO, biomethanol and bio-LNG deliver demonstrable reductions, provided they meet strict sustainability criteria. If they do not, they are legally considered fossil and the least favorable fossil emission factor applies. A certification chain with GHG declaration and batch tracking is therefore necessary to avoid discussions about double counting and to keep the reduction value legally sound.
On the non-fuel side, wind-assisted propulsion creates additional room. FuelEU values deployment up to an intensity reduction of a maximum of 5%, depending on the contribution of wind energy to total energy consumption. Success requires integration with route planning, stability calculations and deck layout, including sightlines and force transfer to the ship’s structure. This allows the aerodynamic gain to be realized without compromising safety and operability.
Finally, electrification and batteries mainly strengthen opportunities for GHG reduction in short sea and ferry services. At the quay, electricity counts as zero-emission, which aligns with the OPS obligation from 2030. In deep sea, the added value lies in peak shaving, feeding hotel load and supporting maneuvering. By linking these applications to OPS in ports with sufficient grid capacity, additional room is created to meet the reduction targets.
The optimal portfolio usually combines multiple pathways. By calculating scenarios per ship class and connecting availability, safety and certification to operational reality, a consistent technology and fuel strategy emerges that strengthens both compliance and operations.
Contracts and Risk Allocation in Maritime Charters
FuelEU sets requirements for a ship’s fuel performance. The internal allocation of compliance costs and risks is left by the regulation to the contracting parties. The holder of the FuelEU DoC is formally responsible for compliance. In practice that is often the owner or the technical manager. Under a bareboat charter the charterer can fulfill this role. Because in many charter models the charterer determines the fuel choice, a negative compliance balance can arise for which the owner remains legally liable. This requires explicit agreements about risks, responsibilities and costs, so that incentives and obligations remain balanced.
New contract clauses provide guidance. The owner keeps the monitoring plan current and provides a monthly or per-voyage overview of the cumulative compliance balance. If a negative balance looms, the owner can pass through a surcharge equal to the expected FuelEU penalty, payable in advance or no later than early June of the following year. Charterers may supply alternative fuels, provided they are certified in accordance with the relevant sustainability and origin criteria.
For long-term time charters that span one or more full reporting periods, it can be established that the charterer may bank or pool surpluses and, in multi-year agreements, may apply borrowing. For short-term time charters, rights to banking and pooling usually remain with the owner, reporting applies per month or per voyage and any surcharge can be passed through.
For voyage charters the responsibility for compliance and pooling rights almost always lies with the owner, while under bareboat charters the charterer legally acts as DoC-holder. In all cases, the party bearing the risk decides on fuel mix, allocation of RFNBO volumes and use of OPS hours. This keeps operational control directly aligned with the financial and legal consequences.
Practical Roadmap for Compliance and Investments
Meeting the FuelEU requirements requires not only technical adjustments, but also strategic choices that align. The roadmap below translates the framework into concrete actions on board and ashore. The steps follow a logical sequence, but in practice many elements can be executed in parallel. By working with reliable data and clear responsibilities, each next decision is better substantiated, which makes compliance predictable, reduces risks and accelerates the investment cycle.
The first step is a fleet analysis, in which the current greenhouse gas intensity is established per ship based on MRV data. The main sources of CO2, CH4 and N2O are identified and a reference year is established. By simulating target values for 2025 and 2030 with scenarios for fuel mix, OPS hours and wind assistance, a precise gap analysis emerges. This prevents generic measures from being applied that do not fit the ship’s specific operational profile.
The monitoring plan follows from this analysis. Each ship within scope must have a plan approved by an accredited verifier no later than August 31. Where possible it is aligned with the existing EU-MRV plan, supplemented with sections on OPS, zero-emission technology and well-to-wake emissions. By harmonizing LHV tables, mass balances and voyage definitions between MRV and FuelEU, a consistent basis is laid for all reports.
With the monitoring structure in order, attention can shift to investments. An optimal fuel mix is chosen per ship class, taking into account the availability and logistical feasibility of OPS and the potential of wind-assisted propulsion. RFNBO volumes are contracted with clear GHG specifications and delivery windows. By combining retrofits with class inspections and dry-dock periods, downtime remains minimal.
In parallel, flexibility is considered. For each ship it is determined how banking, borrowing and pooling will be used, possibly together with sister ships or strategic partners. In the first years borrowing can be useful to spread investments, while banking becomes more attractive once guaranteed RFNBO deliveries or new OPS facilities become available.
To ensure that these choices also stand up legally, the next step is contractual anchoring. This determines who manages the GHG compliance balance, how surpluses and deficits are valued and who decides on the use of flexibility mechanisms. In addition, bunker specifications are linked to certification requirements and audit rights, so that commercial arrangements directly align with the legal framework.
Finally, there is automation and quality. With THETIS-MRV, including the FuelEU module, all data is entered per voyage. Automated checks on density, LHV values and plausibility, combined with root-cause analyses in case of deviations, make data quality part of day-to-day operations.
When this roadmap is integrated with the ETS strategy, additional synergy emerges, lower fuel consumption reduces ETS costs, while early deployment of RFNBOs and OPS lowers both GHG intensity and absolute emissions. By applying internal shadow prices per gigajoule, investment decisions become consistent and comparable, which makes the route to 2030 and 2050 more manageable.
Strategic Implications for Compliance, Certification and Competitive Position
FuelEU Maritime marks a system change in the decarbonization of seagoing shipping. The regime requires not only new fuels, but also professionalization of project control, contracting and data flows. The mandatory integration of well-to-wake measurements, including methane slip, increases the need to substantiate engine and fuel choices technically, legally and economically. That requires cooperation between engineering, legal and finance so that each investment contributes to compliance.
Targeted investments in RFNBOs, sustainable biofuels, OPS and wind-assisted propulsion deliver a compliance benefit and strengthen market position. Combined with the ETS strategy this produces gains, lower intensity figures and fewer absolute emissions, with a proportional saving on allowances.
Careful allocation of risks and costs in charters anchors the polluter-pays principle in the private sphere and prevents disputes during the reporting cycle. Those who plan investment moments strategically, automate data flows and deploy flexibility mechanisms purposefully accelerate the transition to zero-emission shipping. In this way, compliance and competitiveness reinforce each other in practice.