Ethanol Gains Ground as Viable Alternative Fuel for Deep-Sea Shipping

New research from the Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping positions ethanol as a practical near-term decarbonization pathway for portions of the global merchant fleet. The study, conducted with major industry partners including NORDEN, TotalEnergies, and engine makers, shows that ethanol can be adapted to methanol-compatible engines with minimal modifications and offers higher energy density than methanol itself. Maersk has already validated this pathway on the Laura Maersk container ship, progressing from 10% ethanol blends to pure ethanol trials by mid-2026, and completed the first commercial ship-to-ship ethanol bunkering of a deep-sea container vessel in Houston.

For shipowners, the economics matter as much as the technology. Retrofitting conventional diesel-powered bulk carriers to use 30% ethanol blends could cost roughly half the price of full methanol conversion, making it attractive for certain vessel types and operating profiles. However, significant hurdles remain for diesel fleet adaptation: ethanol dramatically lowers the flashpoint of fuel mixtures below SOLAS safety thresholds, and ethanol-diesel blends separate during cold storage, requiring either onboard blending systems or specialized handling protocols.

The viability of ethanol as a decarbonization tool depends critically on sustainable production and supply chain availability. The Center has deliberately deferred assessment of lifecycle emissions and production scalability to separate studies, signaling that fuel origin and carbon intensity will be as important as technical compatibility. For supply chain leaders, this news represents a widening set of decarbonization options but also emphasizes the complexity of evaluating fuel pathways by emissions performance, not just operational feasibility.