[osense]

I'm surprised to see the service speed listed at 6 knots. Seems quite low for a container ship, no? From my limited anecdotal evidence of having cargo ships pass my sailboat, they're usually doing easily 10-15 knots. I wonder if that's related to battery efficiency being better at lower power consumption? In any case, for a short route mostly in shielded waters, as presented in the article, this doesn't seem like a hige downside.

I also have to comment on the "emission-free" moniker. Was the construction of this ship emission-free? Definitely not. Is the maintenance of the ship going to be emission-free? Probably not. I'm not saying we shouldn't be trying to reduce our emissions, but seems like nowadays there's often an almost indistinguishable line between actually trying to produce a sustainable product, and just doing greenwashing to get more government grants and investors onboard.

[Stevvo]

Slower speeds are much more efficient. In displacement vessels the energy required is proportional to the square root of the speed.

[osense]

Is this independent of the hull shape and hydrodynamics? Or how does that influence the energy reuirements?

[Stevvo]

It all contributes, and depending on the sea state and heel angles also.