Designs for battery tankers to transport renewable energy by 2026 | Hacker News Reader

Designs for battery tankers to transport renewable energy by 2026

maritime-executive.com

24 pointsrsecora46 comments

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.

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.

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

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.

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.

> 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?

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/

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.

> 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.

Other threads are discussing whether the specific numbers here pencil out, but to step back a second and take a high-level snapshot: the trend here is that batteries are becoming cheap enough to consider bulk transport of electricity.

Yes, there's questions about weight and power density and all that, but slap your classic techno-exponential curve on all that and ask yourself what becomes interesting after 10 years of riding the experience curve?

There's already companies looking at filling a shipping container with batteries and using them for temporary events like construction sites, concerts, or disaster relief. This ship idea takes it to the extreme: boats have the lowest dollar-per-weight-mile costs, so what use-cases become interesting when the limiting factor becomes techno-decreasing battery costs?

I see several shortcomings with this design:

- High investment cost to adopt the tech.

- High manufacturing and maintenance cost for this level of integration. (especially due to the battery short lifespan)

- Energy loss during power transfer, when unloading the electricity.

A more modular design could work better imo. Make it so the vessel can load/unload standard power modules via rails/warehouse-like robots. The standard power modules could be made from smaller, standard batteries such as Tesla powerpacks or future grid battery modules so that the cost of using this vessel on top of a renewable grid becomes marginal, and hot-swapping the fully charged modules with the empty ones ensures power is not transmitted twice.

Other benefits of standard modules is that production costs for battery modules will go down, and transmission could also happen on land over trains or trucks if the economic equation works out, or for extremely remote areas with limited local power generation capabilities.

In fact a whole ecosystem of hot-swappable residential modules could be bootstrapped, making it easy to deploy a single home installation or a microgrid in a remote area, all the way to a town, city, island or nation-wide grid.

The proposed capacity of 241 MWh is equivalent to a tank truck of gasoline, 26 m³.

Insane, the amounts of energy we casually carry around. It has to be said, though, that electricity is useful for a lot more than petrol is. If you'd want to use this 26m³ for powering some machine, like your vacuum cleaner, you'll lose a lot of this energy in the process (wikipedia says "most engines retain an average efficiency of about 18–20%") whereas putting electrons through a wire into an electric motor has much lower losses ("up to 98% for permanent magnet motors", another Wikipedia article).

Indeed, really you would need four tank cars (104 m³).

EDIT: or, 1.73kg of natural uranium used in a standard PWR fuel cycle.. or, 31 grams of natural uranium utilized in a fast reactor.

Edit edit: forgot to convert for thermal efficiency again, make that 7kg of uranium for a PWR cycle, and 124 grams in a fast reactor.

To clarify the 26 m³, that is the gasoline volume with the same energy content as the proposed ship. Tank truck capacities seem to be in the range from 10 m³ for small ones to semi-trailers with 40 m³.

I wonder if this is worth it. Such a ship is a large one-time investment - just like connecting landmasses with a cable is, which would be a lot more efficient long term I imagine.

The boat can change route.

And still needs a grid to connect to. Either that or a ton of USB plugs and really long USB-C cables.

Please dont make it a mini-usb connector, I have only just managed to purge the last of the electronics that require this standard from my home.

Nah, we are switching to USB-D

Wireless charging.

And as a bonus, during war times it doubles as a death ray.

I don't understand ... there are already transmission cables for moving electricity around ... what is a use case that makes this worthwhile?

"Forty percent of all shipping cargo consists of fossil fuels":

* https://qz.com/2113243/forty-percent-of-all-shipping-cargo-c...

* https://news.ycombinator.com/item?id=29850631

I'm not sure it is a good idea to expend energy to move energy.

All "unlocked" energy requires a certain energy investment: drilling, pipelines, refineries, tankers, setting power lines, running a solar silicon factory, setting up a wind turbine...

The question is always what's your multiple on energy return from energy invested, and how does it compare to the alternatives: https://en.wikipedia.org/wiki/Energy_return_on_investment

This is a terrible idea when nuclear powered aircraft carriers and submarines exist.

Just...build a couple of those reactors into this thing, put it under military control for logistics purposes and get a much better system.

Edit: in fact basically you'd take the tanker form factor, build in a large desalination plant, hospital and kitchen and basically produce the disaster relief/logistics supertanker hopefully at a lower price then an aircraft carrier.

The Russians already did something similar: https://en.wikipedia.org/wiki/Akademik_Lomonosov

Ok, according to https://en.wikipedia.org/wiki/Floating_nuclear_power_plant the US had a prototype in the 1960s already, but the project was ultimately scrapped...

Nuclear powered civilian ship run by minimum wage staff with a Liberian or Panamanian flag? Are you sure?

Oh, military control. At which point the cost becomes either ridiculous or hidden in a different budget.

>nuclear powered aircraft carriers and submarines exist.

provided you dont mind 10x-ing your electric bill...

A tanker full of batteries isn't going to move enough energy to be worth it.

Chemical batteries are god awful for stationary power applications. You'd be better off synthesizing carbon fuel from the air or electrolyzing hydrogen...or using the technology we already have which can just do it (nuclear).

That's basically the assumption made by this project.

Right. As I mentioned above I dont think it's a good idea either. Not energy dense enough.

It makes much more sense to just repurpose container ships - of which there is a glut I think.

What we should be transporting (ships, trains, trucks) is standard modular power units. Perhaps the glut of shipping containers could be repurposed to manufacture large standard modular power units.

it would be super ironic if we were using old crude oil powered container ships to move around units of renewable energy

This is not going to work.

Now I will get out of the way of the people trying to make it work.

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