Those are some big numbers. It makes me think of a crazy thought experiment:

How many MW could a container ship carry by literally shipping energy stored in batteries?

As in they fill up entirely with batteries, sail to a desert, plug into a cable to charge on cheap solar, charge up, sail to a population center, plug in to discharge. Repeat.

That's easy to work out from the parent comment. They conclude that 16,000 tons of batteries are needed for propulsion, with a total capacity of 3GWh.

For a typical 40kton cargo ship, that leaves 24,000 tons for more batteries, for a energy cargo capacity of 4.5GWh. The average US citizen uses ~770,000 BTUs of energy per day, or 0.23MWh. This "energy cargo" of this ship would provide the entire energy needs of a city of 20k people for one day. (I am being a little unfair, by assuming that everyone uses electricity for all of their energy needs in this scenario).

A japanese startup is working on a (surprisingly small) battery energy "tanker":

https://power-x.jp/en/newsroom/Introducing-the-world%E2%80%9...

I think there are some startups working on cargo train "tankers" in the US too.

An idea I had after seeing the tanker concept was to have the battery carrier also serve as a generator via wind power. If its a huge ship I suppose you could just stick a turbine on it and go where the wind is blowing. I think a more fun concept is generating power off of a smaller scale cat- or trimaran generating both propulsion and power by sailing conventionally.

Ha, that's like the quote: "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway."

Panamax ship is 5000 teu (twenty foot shipping container equivalent)

I think you get about 4 MWh per TEU ( based on my 12V 100Ah battery)

so about 20 GWh