[Gwypaas]

> Regarding bunker oil, there are ships under construction that will use hydrogen instead of bunker oil. Also interesting is that while large ships burn bunker oil, they do so to power a generator that powers an electrical engine. This is true for modern oil tankers and large container ships.

That is not the case. They are often direct drive through a reversible engine for maximum efficiency without any clutches and the most minimal gearbox possible. The engines themselves tend to be low rpm ultra-long stroke two-stroke diesel engines. They often even have shaft generators to shut down the smaller more inefficient generators. This further forces a set design speed to have the correct electrical frequency.

Ferries, off-shore vessels and cruise ships are increasingly becoming diesel electric though due to both large electrical loads and larger variations in load due to their operational patterns.