Hydrogen fuel

Hydrogen used as marine fuel is stored compressed or as a cryogenic liquid at about minus 253 degrees Celsius, feeding fuel cells or internal-combustion engines with zero tank-to-wake CO2. Its very low volumetric energy density demands large, heavy tanks, which limits it to short-sea and harbor craft rather than deep-sea trades today. Green hydrogen from renewable electrolysis is also the feedstock for green ammonia and e-methanol, so its main near-term maritime role is upstream of those carriers. Carriage and use are being addressed in developing IGF-Code amendments.