Corrects B30 pricing in paragraph 5.
An International Maritime Organization (IMO) proposal for ship owners who exceed emissions reduction targets to earn surplus credits will play a key role in biofuel bunkering options going forward.
The price of these credits will help determine whether B30 or B100 becomes the preferred bio-bunker fuel for vessels not powered by LNG or methanol. It will also influence whether biofuel adoption is accelerated or delayed beyond 2032.
At the conclusion of its meeting earlier this month the IMO proposed a dual-incentive mechanism to curb marine GHG emissions starting in 2028. The system combines penalties for non-compliance with financial incentives for over-compliance, aiming to shift ship owner behavior through both "stick" and "carrot" measures. As the "carrot", ship owners whose emissions fall below the IMO's stricter compliance target will receive surplus credits, which can be traded on the open market. The "stick" will introduce a two-tier penalty system. If emissions fall between the base and direct GHG emissions tiers, vessel operators will pay a fixed penalty of $100/t CO2-equivalent. Ship owners whose emissions exceed the looser, tier 2, base target will incur a penalty of $380/t CO2e. Both tiers tighten annually through 2035.
The overcompliance credits will be traded on the open market. It is unlikely that they will exceed the cost of the tier 2 penalty of $380/t CO2e. Argus modeled two surplus credit price scenarios — $70/t and $250/t CO2e — to assess their impact on bunker fuel economics. Assessments from 10-17 April showed Singapore very low-sulphur fuel oil (VLSFO) at $481/t, Singapore B30 at $740/t, and Chinese used cooking oil methyl ester (Ucome), or B100, at $1,143/t (see charts).
If the outright prices remain flat, in both scenarios, VLSFO would incur tier 1 and tier 2 penalties, raising its effective cost to around $563/t in 2028. B30 in both scenarios would receive credits putting its price at $653/t and $715/t respectively. In the high surplus credit scenario, B100 would earn roughly $580/t in credits, bringing its net cost to about $563/t, on par with VLSFO, and more competitive than B30. In the low surplus credit scenario, B100 would earn just $162/t in credits, lowering its cost to approximately $980/t, well above VLSFO.
At these spot prices, and $250/t CO2e surplus credit, B100 would remain the cheapest fuel option through 2035. At $70/t CO2e surplus credit, B30 becomes cost-competitive with VLSFO only after 2032. Ultimately, the market value of IMO over-compliance credits will be a major factor in determining the timing and extent of global biofuel adoption in the marine sector.

