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Comment by Gasp0de | Hacker News Reader

I would think this can only ever be useful in places where a connection is needed only for a short time, e.g. to compensate the loss of a connection. Not only are battery tankers a huge investment, they also have an extremely short lifespan. According to the article, their batteries have a lifespan of 6000 cycles and a capacity of 241MWh. That means that during it's lifetime, one ship can transport 1446000MWh of energy.

According to this study (https://www.sciencedirect.com/science/article/pii/S258900422...), it costs 41.5$ to transport 1MWh 1000 miles across high voltage dc lines (including initial investment). That would be 10,000$ for a 1000mile trip for this ship. I believe there might be some edge cases where it is absolutely impossible to build cables or the link is only needed for very short timespans but other than that I don't see this become profitable.

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I also checked the date of the article several times to make sure it's not an April fools' joke... and then I thought to myself "is it really so difficult to build power lines now that they have to resort to shipping batteries around?".

Even for those edge cases where it's absolutely impossible to build cables, shipping e.g. liquid hydrogen or another renewable fuel is probably a better alternative...

Or just accept that for some cases, using non-renewble energy sources is more feasible. E.g. disaster relieve, instead of parking a battery ship, that still needs a grid to connect to, use diesel generators and conventional tankers.

Worth noting that 6000 cycles of the most extreme hypothetical 180 mile round trip would take 15 years, assuming the ship always travels at its max speed of 10 knots, and always charges and discharges at its max rate of 0.33C. Realistic load and duty cycle would be much less than that, so lifetime would be multiples. This ship may or may not have a plausible use case, but it doesn’t sound like cycle life would be the limiting factor.

Time also degrades batteries, after 15 years you will have much less capacity than you started with even if you don't use any cycles.

> a capacity of 241MWh

At an expensive $100/MWh that's about $25k worth of power. Who builds an expensive ship to transport $25k worth of anything?

Even with electricity being one or two orders of magnitude more expensive, this would be a bad idea.

> It expands on earlier concepts presented by [...] startup [...]

Looks like the main business is fleecing VCs.

$100/MWh is pretty cheap. Around here the retail rate I pay on my power bill is something like 12 cents per kWh which is $120/MWh.

But on your broad point I agree. I couldn't see it being economical for anything other than emergencies or other situations where power is waaaaayyy more expensive than retail rates.

> Around here the retail rate I pay on my power bill is something like 12 cents per kWh which is $120/MWh.

A cargo ship does not retail its load. You would still need a transport and a distribution network behind it, as well as a production plant somewhere across the world.

With $100 worth of power at the ship terminal, you could very well pay another $50-60 of transport cost and maybe $30-40 in taxes.

This cannot be better than transporting electricity over wires. Currently long distance cables are laid for Internet. We already have experience doing that and does not increase sea faring traffic. Even if someone wants to just transport charged electrolyte instead of actual batteries why not use pipelines? Humans have experience transporting oil and gas over large distances over pipes so that too can be done. Poor investors behind this are so doomed.

> I would think this can only ever be useful in places where a connection is needed only for a short time, e.g. to compensate the loss of a connection.

The one place I can see this being really useful is islands. Although even then it would have to compete with the same set of batteries permanently onshore with a renewables setup.

No, I don't think battery tankers will ever work. Maybe if people get a good electricity-to-fuel solution or flow batteries then those will be shipped around, in more conventional tankers.

(Flow batteries are in their limit still less dense than fuels, because the fuels store energy in their bonds and electrolytes can only store it in their redox state)

This from the same site looks more promising: https://maritime-executive.com/article/startup-uses-ammonia-...

>The one place I can see this being really useful is islands.

Islands would likely be better off with wind, solar, permanently installed batteries and maybe the odd shipment of hydrogen.

It would still only be useful for islands that are so small they can't build enough solar, wind or geothermal and at the same time so far away from any mainland that cables are not feasible. How many of these islands do you know?

It might help to have some context. I pulled up the NH Net Metering rules and see that they charge the following:

Transmission fees (FERC/federal fees): $12.92/625kWh = $0.02

Distribution fees (PUC/local fees): $25.88/625kWh = $0.04

Compared to this ship: 1000 miles: $41.5 / 1000kWh = $0.04

A full comparison would require knowing what distances NH moves power over, and what other transmission would need to be coupled with one payload from the ship. But I think that this shows the costs may be in the right ballpark. And - having this as an option where lines are not possible (NIMBYism, etc), or in the face of natural disasters, is a huge win.

Now.. is that ship electric?

> having this as an option where lines are not possible (NIMBYism, etc)

Not a lot of nimbys have a backyard in the middle of an ocean, I'll grant you that.

> or in the face of natural disasters

If you really mind transporting a few generators on a plain cargo ship, this could be an alternative, I guess.

600 0-100-0 cycles or perhaps 6000 20-80-20 cycles. And then after you've hit the cycle limit, your batteries are still good, but only have 80% of original capacity. Not sure how much it helps to make the numbers feasible though.

We have an event two or three times a year which needs a lot of power at a remote site. We get in a hydrogen generator, the hydrogen is produced by renewable energy.

To me that feel more suitable for areas like building sites etc.

Any chance you could share some more details about this portable hydrogen generator that you’ve used? I’m not seeing many widely available commercially.

https://www.geopura.com/

Well, we have internet using hundreds of expendable satelites that is somehow expected to be cheaper than 5G or fibre. For some reason, people really seem to dislike cables...

Vast majority of our internet goes through submarine cable. Besides satellites aren’t launched from your home and land at google servers every time you open google.com which would be similar to what the tanker would be doing

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