460-foot “battery tanker” set to ship electrons by 2026

From article:

"Why not just put down an underwater cable? That's a fine question. PowerX points out that Japan is surrounded by deep seas, and prone to earthquakes, and says in a press release that "the ship-based solution resolves issues such as long downtime from undersea cable malfunctions and repairs, as well as the high costs associated with ultra-high voltage connections and substations.""

1) Two islands exist relatively close to each other. 2) Both have enough wind power to meet demand on windy days. 3) Deep waters, strong tidal currents, tsunami risk or some combination make power lines between the islands somewhat expensive or unreliable. 4) Battery storage is required to meet demand on days with little wind. 5) Storing these batteries on ships is not significantly more expensive than storing the batteries on land. (Maybe real estate prices are high, regulations are stricter on land, etc.)

In such a case, it may be more economical to move the ship holding the batteries than to set up cables intended just for low wind periods. And if there are many islands involved, an ecosystem of ships may scale better than cables, for instance if demand is seasonal or varies for other reasons.

Basically, these are similar reasons to why LNG regasification ships exist, instead of just building fixed land-based facilites where needed.

When you charge a battery you are pushing electrons from one chamber in the battery to another. A discharged battery is like two tanks of water at equal levels, charging is like pumping water from one to the other so one has a higher level and thus potential energy.

Then again, they could well be right on a one-ship basis and maybe that's all they need, and this needs less capital expenses like, say, a hydrogen handling terminal at each end.

The solution would seem to be to generate power in Japan not to transport it there by such bizarre (I agree with the title here) method. But let's reserve judgment and see how it plays out in practice, I'm going to watch this one just to see how real life matches my intuition about this project.

Even the larger version doesn't make a whole lot of sense, you'd be looking at keeping the ship in port for quite a while unless those batteries are going to be charging and discharging at very high rates but that would shorten their life (and hence the number of trips). They are aiming to do 'short runs' only (100 km is mentioned in the article but the economic range is a bit larger) which makes it even more dicey economically.

Their transportation costs per KWh as quoted in the article exceed current generation costs by a factor of three already. 214 MWh is a proverbial drop in the bucket on grid scale and even 10x isn't all that much, and you can only deliver power if you have enough of those vessels to guarantee overlap at the destination or you're going to have to deal with outages.

I wonder who is investing in this project.