Hydrogen Fuel Cell

A hydrogen fuel cell is an electrochemical device that converts hydrogen and oxygen into electricity, heat, and water with no carbon dioxide at the point of use. Hydrogen oxidizes at the anode, oxygen reduces at the cathode, and the only tank-to-wake byproduct is water vapor. Marine units reach about 50 to 60 percent electrical efficiency, well above the 40 to 45 percent of a medium-speed diesel. The well-to-wake carbon footprint depends entirely on the hydrogen source: green hydrogen from electrolysis is near-zero, gray hydrogen from steam methane reforming is not. The proton exchange membrane type dominates marine demonstrations on power density.