The International Maritime Organization's (IMO) proposed global greenhouse gas (GHG) pricing mechanism might not drive significant uptake of green methanol and green ammonia by 2035, given current market prices.
Despite introducing penalties on high-emission fuels use and tradable surplus credits for low-emission fuels, the mechanism does not sufficiently close the cost gap for green alternatives. Under the system, starting in 2028 ship operators will face a two-tier penalty: $100/t CO₂e for emissions between the base and direct GHG intensity limit, and $380/t CO₂e for those exceeding the looser base limit. These thresholds will tighten annually through 2035. Ship operators can earn tradable credits for overcompliance when their GHG emissions fall below the direct limit.
Assuming a surplus CO₂e credit value of $72/t — mirroring April 2025's average EU emissions trading system price — green ammonia would earn about $215/t in surplus credits in 2028 (see chart). This barely offsets its April spot price of $2,830/t VLSFO equivalent in northwest Europe. Bio-methanol would receive about $175/t in credits, offering minimal relief on its $2,318/t April spot price.
Currently, unsubsidized northwest Europe bio-LNG sits mid-range among bunker fuel options under IMO's emissions framework. While more expensive than HSFO, grey LNG, and B30 bioblends, the bio-LNG is cheaper than B100 (pure used cooking oil methyl ester), green ammonia, and bio-methanol.
To become cost-competitive with unsubsidized bio-LNG — priced at $1,185/t in April 2025 — green ammonia and bio-methanol prices would need to fall by 57pc and 49pc, respectively, to around $1,220/t VLSFOe and $1,180/t VLSFOe by 2028. Unless green fuel prices drop significantly or fossil fuel prices rise, the IMO's structure alone provides insufficient economic incentive to accelerate green ammonia and bio-methanol adoption at scale.
