Battery electric may work at some smaller scales such as local ferries but not for moving 100,000 tons across oceans. The energy density just isn't there.
Nuclear would be good but would make the ships a huge piracy/terrorism target. You'd need military escorts for them.
Dunno if this is actually true. There's plenty of stuff going around every day in unguarded ships that have significantly more accessible terror-potential than anything you can put together with a small nuclear reactor.
If recent events in the Panama Canal or Baltimore isn't convincing enough of the disruption a single misplaced cargo ship can cause, it's hard to argue against Tianjin[1] and Beirut[2]. Like those disasters, mind bogglingly destructive as they were, were caused by incompetence and negligence. It's hard to imagine what someone with malicious intent could cook up with nearly 3000 tons of ammonium nitrate.
It would definitely also work for 100 000 tons, but then a sizable percentage of those 100 000 tons will be battery and not freight. Unless the ship should make stops all the time to recharge, which is expensive as well, so no, batteries are not a economical solution for freight ships.
But fuel cells might be a solution
https://www.fraunhofer.de/en/press/research-news/2021/march-...
https://www.goodreads.com/book/show/40859000-delta-v
Though we only encounter microwave beaming in the sequel, Critical Mass
I found the book a very good read, super realistic. 10/10 for realism/science/research and 8/10 for story. It's very optimistic. Nice to read with the war in Ukraine and progressive climate change not filling with optimism.
If you like other optimistic (mostly) hard sci fi, I recommend the mars trilogy from Kim Stanly Robinson, in case you missed that so far.
A Panamax ship can consume 63,000 gallons a day. To do that with batteries, you'd basically need a whole ship of batteries.
63000*33*.33/(3854*0.9)*84000 = 16,782,563 lbs or ~7,600 metric tons worth of batteries for 1 day's worth of "electric fuel"
Lot's of possibilities, but I think the biggest hurdle is, that diesel is still very cheap.
How fast do you need to go to hydrofoil when you're carrying 200 cars?
They're working on a battery elecrtric version of my local ferry, and yeah, it's gonna be a lot of charging infra; but in theory the operating costs are much lower, and the charging plans mean they increased grid redundancy for me, so that's nice. This is my current ferry: https://wsdot.com/ferries/vesselwatch/VesselDetail.aspx?vess...
A sci-fi future would have small(ish) and safe fusion reactors propelling massive container ships on hydrofoils going wheeeee.
It has been attempted and found wanting, but it is certainly possible.
You'd probably not want to just replace the engines in current ships, and instead require that they be maintained and crewed by responsible countries.