Glossary · Emissions & reporting
Bunker fuel, biofuel and green methanol
Also known as Bunkers, VLSFO, Green methanol, and Marine biofuel.
The fuel a ship burns, the surcharges it puts on your invoice, and what a carrier is actually selling when it offers you a low-emission alternative.
Published
Bunker fuel is the fuel a ship burns, and “bunkering” is the act of taking it on. Most container ships run on very low sulphur fuel oil, VLSFO, which replaced heavier fuel on most trades when the sulphur limit tightened in 2020.
It reaches you as a surcharge. Fuel is the largest variable cost of a voyage, so carriers price it separately from the base rate and adjust it — which is why a rate you agreed in October can arrive in February with a different total.
The second line next to it
There is now a carbon surcharge alongside the fuel one. Shipping sits inside the EU Emissions Trading System, so a carrier must surrender allowances for emissions on European trades and passes that cost through. FuelEU Maritime adds a separate requirement on the greenhouse-gas intensity of the energy a ship uses. Both land on the same invoice, and both get smaller when a ship burns less — which is the mechanism behind wind-assisted ships.
What “green” fuel is, and what you are buying
Two alternatives are actually on the water. Marine biofuel is usually a blend of waste-derived biodiesel with conventional bunkers, which needs no change to the engine. Green methanol — made from biomass or from renewable hydrogen and captured carbon — needs a dual-fuel engine, and the ships that can burn it are being delivered now rather than retrofitted.
The important thing for an importer is how it is sold. Carriers offer these as separate paid products with a certificate attached: the fuel goes into whichever vessel is convenient, and your booking is allocated a share of the reduction on paper. That is a legitimate method, and the only one that works while the fuel is scarce. But it means you do not get a lower footprint by luck. You get it by buying it, and the certificate is what your customer’s auditor will want to see.
FAQ
Will booking a low-emission ocean product actually reduce my reported emissions?
Yes, if the certificate is issued under a recognised method and you keep it. What you are buying is a documented share of an emissions reduction made somewhere in the carrier’s fleet, not cleaner fuel in the specific ship carrying your reefer. That distinction matters when a buyer asks how the reduction was evidenced, and not at all to the atmosphere.