From our experience working with shipowners including the Van Weelde Group, Bore, Stenersen, BBC Chartering, and Neste, and administering more than €100 million of emissions exposure in 2025-26, here’s what we’ve learned about the surplus generation process:

What creates a surplus

A vessel’s compliance position under FuelEU Maritime is determined by its Greenhouse Gas (GHG) intensity, measured in grams of CO2 equivalent per megajoule (gCO₂e/MJ), relative to the target set for that reporting year. When a vessel’s measured intensity falls below the required value, it generates a surplus.

Not all low-carbon fuels generate surplus at the same rate. Bio-LNG has driven the majority of total market surplus to date, with smaller contributions from liquid biofuels such as Fatty Acid Methyl Esters (FAME) and Hydrotreated Vegetable Oil (HVO).

The reason lies in the Well-to-Wake (WtW) calculation methodology, which accounts for emissions across the full fuel lifecycle: from production and transport (Well-to-Tank, or WtT) through to onboard combustion (Tank-to-Wake, or TtW). Bio-LNG derived from waste feedstocks can carry a significantly negative WtT value, meaning that even after combustion emissions are added, the vessel’s overall GHG intensity can remain negative. Liquid biofuels reduce emissions compared to conventional fuel oil but rarely produce a negative overall intensity.

The practical result is that a tonne of bio-LNG typically yields a much larger volume of tradable surplus than an equivalent volume of biofuel. This mathematical relationship is fixed, regardless of short-term fuel price movements.

GP Tanker on a voyage departing from Rotterdam to Fos-sur-Mer could produce up to 700 tCO2 poolable compliance balance surplus. Pooled compliance prices in 2025 peaked at 250€/tCO2e which could have generated up to 175 000 € extra income for the surplus generator.

Example of how much surplus can be created under one voyage. Graph explaining how a GP Tanker on a voyage departing from Rotterdam to Fos-sur-Mer could produce up to 700 tCO2 poolable compliance balance surplus.

From fuel selection to tradeable surplus

Surplus doesn’t appear automatically when low-carbon fuel is bunkered. It requires active management across four stages.

1. Route optimisation: The process begins before fuel is loaded. FuelEU Maritime applies to energy used on voyages within, into, or out of EU/EEA ports, so strategically allocating low-carbon fuel to high-exposure trade lanes maximises the commercial return.

2. Proof of Sustainability: To claim a lower emissions intensity, each bunkering event must be supported by a valid Proof of Sustainability (PoS) issued by an accredited certification body. This document provides the legal evidence of the fuel’s origin and lifecycle emissions intensity; without it, the lower intensity cannot be applied.

3. In-year tracking: Compliance balances are locked at year-end, but operators don’t need to wait until December to understand their position. Accredited verifiers can review fuel documentation and issue interim statements throughout the year, confirming volumes consumed and preliminary surplus generated. For pool managers, these statements provide the visibility needed to negotiate forward commercial agreements with deficit vessels well ahead of the deadline.

4. Final verification and pool submission: After the reporting year closes on 31 December, operators submit their annual fuel consumption reports to accredited verifiers by 31 January. Once final compliance statements are issued, surplus can be formally transferred within an organised pool to offset deficits in other vessels before the regulatory submission deadline.

A pool, in this context, is a contractual arrangement under which multiple vessels aggregate their compliance positions. Over-compliant vessels sell their surplus to those in deficit, with commercial terms agreed between the parties. FuelEU Maritime provides no central marketplace or fixed pricing for these transfers, so the structure and value of pool agreements is entirely commercial.

The main operational hurdle

For most operators, the biggest practical challenge isn’t fuel selection; it’s administrative timing. A common industry problem has been slow turnaround from fuel suppliers in delivering the Proof of Sustainability. Delays in receiving the PoS prevent verifiers from issuing periodical statements, creating a significant administrative backlog as the January reporting deadline approaches.

Effective pool agreements need to anticipate this. They should handle fuel reallocation across voyages, accommodate slight differences between estimated and actual consumption figures, and include clear contractual protections for both the surplus seller and the deficit buyer.

The regulatory horizon

FuelEU Maritime is a European framework, but the IMO’s ongoing development of a global mid-term GHG framework is moving in a structurally similar direction. Vessels already operating on deeply decarbonised fuels are better positioned to capture compliance value under both frameworks as the global picture clarifies. For owners making fuel and fleet investment decisions now, that convergence is worth factoring in.

Making surplus work

Treating surplus generation as an active operational process, rather than a by-product of compliance, is what separates owners who recover meaningful value from those who don’t. The tools are available now: the right fuel, properly documented, deployed on the right routes, within a well-structured pool agreement.

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