Energy

Bizarre 460-foot "battery tanker" set to ship electrons by 2026

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PowerX is preparing to build a battery-powered ship full of batteries to transport clean electricity in 2026
PowerX
PowerX is preparing to build a battery-powered ship full of batteries to transport clean electricity in 2026
PowerX
The prototype will carry 96 container-sized marine batteries for a total capacity of 241 MWh
PowerX
The Battery Tanker X prototype is scheduled for manufacture in 2025 and trials in 2026
PowerX
Huge 2 GWh Power Arks with solar canopies – that's the eventual plan
PowerX
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Japanese company PowerX is moving ahead with its strange plan to build a "mobile power station" in the form of a 140-meter (460-ft) electric "battery tanker," which will carry 241 megawatt-hours of renewable energy across the sea over short distances.

The idea here is simple enough: renewable energy is often generated a fair distance from where it's most needed, so let's build an electric ship full of batteries, and jolly well ship it there.

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."

The Battery Tanker X prototype is scheduled for manufacture in 2025 and trials in 2026
PowerX

To a man with a hammer, they say, everything looks like a nail. PowerX has a couple of battery factories, which might explain why the company thinks it's a good idea to build a ship loaded with nothing but batteries. Ninety-six container-sized lithium-iron phosphate battery modules will be spaced around this relatively small demonstrator, as well as controllers and charge units.

Currently named "Battery Tanker X," the prototype won't be going very far. Pushing a vessel through draggy water is a nightmare for battery-powered electric propulsion systems, so the ship's maximum range before it burns through too much battery to make the trip economically feasible is slated at just 300 km (186 miles).

A full production "Power Ark" the same size, says PowerX, might move about 4,190 GWh of electricity annually from renewable sources in Hokkaido to meet demand in Aomori just 100 km (62 miles) away, making use of transmission infrastructure already in place but soon to be abandoned as fossil fuel-based generation capacity is gradually shut down.

Huge 2 GWh Power Arks with solar canopies – that's the eventual plan
PowerX

If four ships were deployed around the clock on this route, the company says the cost of power transport would be around US$0.17 per kWh. It doesn't go out of its way to mention that the average retail price of household electricity in Japan is around US$0.25, leaving a scant US$0.07 per kWh to be divided between the renewable power, distribution and retail companies.

The ships will be fitted with gas emission control and fire suppression mechanisms, although the lithium-iron phosphate chemistry is intrinsically quite stable and difficult to ignite. The full-size Power Ark will be much larger than this prototype, and it's proposing to carry eight times as much loaded lithium, meaning it'll hit the high seas carrying a colossal two gigawatt-hours of trapped energy – enough to run about 70,000 average US homes for a full day.

We find this idea somewhat environmentally confusing; assuming these ships are built without carbon-neutral green steel, one wonders how much clean energy they need to cart around, burning clean energy every step of the way, before they can be considered an environmental win.

Still, PowerX must see a business case here, and it's establishing a new subsidiary called "Ocean Power Grid, Inc" to commercialize the technology. With a detailed prototype design now complete, the company aims to have the Battery Tanker X built in 2025 , with "domestic and international field testing planned to commence in 2026." Currently funded to the tune of more than US$70 million, PowerX is setting up a number of partnerships around the idea.

Check out a video below.

Source: PowerX

Editor's note: this piece was amended Thursday June 1, to reflect the fact that these ships use a lower-density, safer chemistry that's unlikely to cause huge battery fires.

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15 comments
paleochocolate
I think it's better to think about the issue in economic terms rather than "green" terms when it comes to building the ship.
jeronimo
I agree. This is a nutty concept.
Set up industry where the power is created.
Brian M
Wonder how the efficiency, both economically and environmentally, stacks up compared to producing and shipping 'green' liquid hydrogen? Those batteries are going to be expensive.
Bob809
I could see an idea like this working around the off-shore wind farms. The ship docks at one of a number of electrical docking stations to 'fill-up' with electricity generated by the wind farms and directly into these ships. Then taken to areas of need wherever they are.
Expanded Viewpoint
Oh man, just when I thought that I had read about the stupidest idea yet in the world, along comes another one that tops it!! What is the cost/benefit ratio here? Or has that arcane idea been relegated to the trash heap of history, like so many other things that we used to guide and live our life by?
jerryd
Battery prices are dropping and getting more dense so this stands a chance. Depends how small a crew, maybe as few as 2 and how well the ship was made. If more time it can go slower on very little power.
Smarter would be selling it as peak power to get more money/kwh.
If $3/day/house, 12kwh average, it should bring in about $22k/trip minus charging, crew, etc costs. So $2k-10k profit/day or 2.
There are few places that can't make all the RE they need locally from solar, wind, hydro, river/tidal, bio/waste/synfuels, geothermal, CSP, CHP, etc.
Austin Heffernan
What are the environmental ramifications when a full production 4,190 GWh "Power Ark" sinks in salty sea water?
TechGazer
I don't recall reading about floating submerged (below ship level) power cables, but that sounds cheaper/simpler/safer than these ships. I haven't checked the state of microwave power transmission, but that seems a competitor too.
Username
What happens to the electricity generated while the ship is not there?
paul314
This might also be useful for smaller islands where there's not enough electricity consumption to make a cable installation profitable (and where conditions for some reason aren't right for solar or wave power). Even if this is an interim idea, it might make good economic sense for 20 years or so (which is going to be the kind of life you could expect from the batteries and the ships before major maintenance.)