More cells than a Model S

[AndreN]

Instead of expensive solar cells and batteries, they could also just plug the ship into the grid at port. That's what two cruise ships do when they dock in Seattle:

Local News | 2 cruise ships will plug into Seattle's power grid | Seattle Times Newspaper

[rolosrevenge]

It seems that they also use the system to power electricity while out at sea so that reduces the total engine load and thus fuel consumption.

[dsm363]

Instead of expensive solar cells and batteries, they could also just plug the ship into the grid at port. That's what two cruise ships do when they dock in Seattle:

Local News | 2 cruise ships will plug into Seattle's power grid | Seattle Times Newspaper

This kind of thing should simply be mandated into the design of all new large passenger ships.

[Yggdrasill]

Here's the technology in action. They have this system in operation in Oslo. (The plug can transmit 4 MW.)

It takes time to get the system up and running, so while the system is connecting, you could use battery power.