Catl Expects Oceanic Electric Ships in Three Years
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The feasibility of electric ships is being put to the test as CATL announces its expectation of oceanic electric ships in three years, sparking a lively debate about the viability of generating enough power from solar panels to propel these vessels. Commenters swiftly chimed in, with some, like themanmaran, pointing out that even with 20,000 square meters of hull space covered in solar panels, the energy generated would be a mere 1-2% of what's needed, around 1-2 MW versus the 60 MW required for propulsion. As the discussion unfolded, a consensus emerged that solar power alone is unlikely to be sufficient, although some suggested that wind power, harnessed through modern sail designs or vertical windmills, could be a more promising alternative. The thread highlights the complexities and challenges of transitioning large ocean vessels to electric power, making it a timely and intriguing discussion.
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- 20k square meters of hull space
- If fully covered with solar panels, on a sunny day, you could expect 1-2 MWh (when averaging in night time)
- Current diesel engines typically output 60MWh continuously while underway.
And that's not factoring in the solar panels getting covered in salt over time and losing efficiency. Plus preventing the ship from actually loading / unloading cargo efficiently.
It's not just a matter of panel efficiency either. If we had magic panels that could absorb 100% of the suns power over the 20k sqm deck, it would only equate to about four times as much (8% of the overall power need).
- Solar: 1–2 MW of average power; ~24–48 MWh of energy per day.
- Diesel: about 60 MW of mechanical power while underway; ~1,440 MWh of energy per day.
60 MWh per what? Per hour? thats just 60 MW continuous POWER or 1440 MWh ENERGY per day.
I’m too lazy to do it myself but 5 minutes of searching and calculating will show you that the area of solar panels required to move a ship is far, far, larger than the area of that ship.
Not to mention that a container ship’s deck is typically completely covered with, well, containers.
Also, lithium isn’t scarce.
I guess in theory that could be solved either with huge removable panels around the containers (to be "put aside" somewhere during the loading operations), or placing containers with solar panels (and ways to deliver the energy to the ship) on the outer sides of the cargo.
Actually, maybe the batteries themselves could be loaded as containers on the sides of the cargo, with solar panels on them; that might increase the risk for the cargo if some catch fire, though
But, I guess it wouldn't be worthwhile.
Honestly DJI and Boeing should get into this business. A boat's sail basically a plane's wing, aerodynamically speaking. They share a lot of similarities with endurance gliders.
Try to approximate the area needed to generate e.g. 50MW propulsion. It would be measured in hectares.
There's more than enough lithium out there, more discovered every month, and the perception that we are limited by lithium is mostly out there because certain media sources are trying to help out there fossil fuel friends by delaying the energy interchange by a few years.
Whether battery ocean shipping containers make technical sense is a different question, but I wouldn't worry about lithium use!
If there is demand for batteries in ships, it is going to be far smaller than for cars, which is currently 80% of battery demand (the rest is mostly grid storage). So ship batteries will at most slow the fall of battery pricing by a small amount.
Lithium, rare earth metals, and a bunch of others are only "scarce" because right now China is the only country willing to put up with the pollution levels that the cheap, dirty version of their extraction produces.
Everything can be produced cleanly, safely, etc... but that comes at a price.
It's like when employers complain that "nobody wants to work". That needs to be translated to "nobody wants to work for the low wages I'm willing to pay".
I wouldn't underestimate what creative and dedicated engineers can accomplish.
If there was some way to expand the PV surface area to beyond the ship deck area.
Besides PV, there's a long history of wind powered ships of course.
Ships tend to go not change course nearly as much on a several day journey. I guess a propellor could run in reverse for regenerative breaking, but it wouldn’t help much.
Also wave based generators that could also act as dampers/suspension and they wouldn’t steal energy from forward motion like wind would (depending on if you’re generating wind energy or using wind to buttress the batteries).
Ideally a combination of sails coupled with batteries and wave generators sounds like it would be very energy efficient.
There are some vessels that have single use emergency brakes, but the latest trend is to have motor 'pods' that are electrical and that can be used both for normal propulsion as well as to perform emergency stops that are quite impressive given the size of the vessels they are on. Typically an oceangoing vessel requires at least 3, but commonly 5 to 10 ship lengths to come to a full stop from moving forward under power. This is not necessarily because of limitations of the propulsion unit, but simply because stopping that much tonnage too fast would do as much damage as a collision would. With classical engines there is far more rotating mass so it would take much longer than with electrical propulsion to react before the beginning of the braking phase.
Unless you have a large sail to generate thrust to spin the propeller...
Ocean going container vessels on the other hand use massive direct drive two stroke diesel engines (usually they only have a single engine). They have no gearbox. The only way to go-astern is to literally start the engine in reverse. This can only be done up to a limited speed, otherwise the windmilling effect of the water passing through the prop would overpower the starting air.
Suffice to say, I'd put a long bet on the overwhelming majority of containerships being powered by internal combustion engines in 30 years time. If we get our act together we might have come up with an alternative / synthetic fuel by then but I wouldn't hold my breath.
Check out the https://swzmaritime.nl/news/2022/11/08/how-abbs-braking-syst... 'wonder of the seas' e-brake system.
Interestingly, there are situations in which it might be helpful where it wouldn't have worked. For example, the Francis Scott Key Bridge incident. The vessel suffering from a blackout caused by a transformer being tripped by a single loose wire.
> The vessel suffering from a blackout caused by a transformer being tripped by a single loose wire.
Transformers don't 'trip'. Circuit breakers do.
Yes, it was a loose wire. But that vessel had regular diesel propulsion so that is not going to make any difference, loose wires can - and do - happen, usually with less far reaching consequences.
The point of the pods is that there are many of them, and they are somewhat redundant reducing the chance of such complete outages. It may well have prevented that particular accident but it may have caused another. This tech is just too new to draw any conclusions.
As far as I understand it every pod has its own dedicated power infrastructure section (batteries, drivers), with the ability to maintain symmetrical drive even in light of multiple failures. So these are right now not for normal propulsion on ocean going vessels (though in a diesel-electric setting they could already be used like that and there are a couple of vessels that use them but I'm not sure if that is for main propulsion as well), but these 'captive torpedos' definitely have a lot of potential.
I'm not sure what this pedantry adds. It's pretty common to say that a piece of equipment tripped for example whole power stations, a generator, a pump etc. When of course it's the circuit breaker protecting that equipment or even occasionally something like a physical over speed trip.
The pod drive architecture, and diesel electric more generally, only makes sense when the other benefits outweigh the efficiency losses of converting from mechanical to electrical and back again. It's very difficult to beat a shaft connected directly from the flywheel to the propeller.
https://en.wikipedia.org/wiki/MV_Ampere
They are quite impressive but they are still very far away from your average ocean going cargo vessel.
Near me, we now have a hybrid ferry, no charging infrastructure, but it still uses much less fuel than before it was refit, so that's cool too. It's bigger than the one you linked and sails on a longer route: 2,499 passengers, 202 vehicles, typically serves an 8.6 mile route.
https://en.wikipedia.org/wiki/MV_Wenatchee
What kind of boats are you talking about?
Most easy to invent types of boat are great if there are no waves. On a river there are basically never waves (yes rapids exist, no that's not common)
However at sea waves are commonplace. Situations where waves are minimal are extremely rare, usually occurring seasonally, when tides are smaller than usual and weather is calm. Sea Lion (the never attempted German invasion of mainland Britain) was predicated on absolutely calm sea because it would have used towed river barges to land troops. If there's a moderate sea but you green light the operation anyway, all your infantry drown and you've just lost the war immediately.
To be successful at sea you want even more buoyancy, to put the top of the waterproof outer parts of the boat above the waves, and you probably also want a keel, rather than having the vessel's bottom flat and sort of resting on the water which won't work well with waves. None of this is impossible, or even especially difficult with quite ancient technology, but it's not trivial, you definitely won't go from rafts to ocean-going freight transport in one attempt.
Diesel-electric, particularly when using Azipods, is great when you need to do a lot of maneuvering in narrow spaces like ports. But for long-haul it's hard to beat the economics of a two-stroke direct drive diesel.
Maybe a hybrid concept for a long-haul ship would be using a direct drive two-stroke main engine, but the auxiliary diesels replaced by batteries?
And this one, under construction now, will have a run time of 90 minutes and charge time of 40 minutes:
https://spectrum.ieee.org/electric-boat-battery-ship-ferry https://news.ycombinator.com/item?id=45844832
Sibling comment is perfectly correct that it starts small and ramps up.
From that article:
> "The ferry format, with its high-frequency turnaround, relatively short segment distances, and shore-based rapid charging, is one of the most promising early use cases for electrification in the maritime sector. Maritime electrification has gained momentum over the past few years"
Early. Momentum.
Moving some noticeable percentage of ships away from fossil fuels is still a win.
However, most large ships apparently have multiple times more fuel capacity than is required for 5,000km of range, which is what makes the electric version realistic.
The current solution is we can bring our own devices and reserve ports on a AWS Data Transfer Terminal. It costs $300-500/hour USD for a 100 GbE bandwidth so not really cheap.
While AWS is stopping doing devices for migration (not economical at low volumes these days). They however still support physical transfers so customers can pack their own planes so to speak with hard disks to the AWS terminal.
[1] https://apnews.com/article/uk-morocco-renewable-energy-xlink...
Allseas is putting the reactors on their vessels as well iirc.
Nuclear powered non military ships do exist, it just not economically feasible .
* a 5,000 km electric range. * 40MW continuous power requirement for a 21.5 knot cruise speed[1] for a 14000 teu container vessel: * the size and weight capacity for the batteries being the same as the fuel capacity for a 14000 teu container vessel (taking the upper figure from [2]) * the battery pack having similar gravimetric (weight) and volumetric(size) energy density as this battery pack in a modern Chinese NMC EV pack[3]
The short version is that the battery vessel would require about 25,000 tonnes of batteries for a 5,000km range under those assumptions, which compares to the current fuel capacity of approximately 13,000 tonnes. Volumetrically, it's even closer - about 17,000 cubic metres, compared to about 13,000 for the bunker fuel.
Furthermore, it's worth considering just how much cargo the ship carries. One teu corresponds to about 33 cubic metres of cargo space (not counting the space taken up by the walls of the container), so the ship can carry about 462,000 cubic metres of cargo. So the additional space required to carry an additional 3,500-odd cubic metres of batteries corresponds to only about 0.8% of the ship's total cargo-carrying capacity.
I was surprised at just how doable this is, to be honest. What threw me is just how much bunker fuel ships can carry; if I'm doing the sums right, a ship like this can carry enough fuel to circumnavigate the globe a couple of times over. It may well make economic sense but it's not really necessary to have that kind of range to operate the ship safely.
[1]https://www.man-es.com/docs/default-source/marine/tools/prop... [2]https://www.freightwaves.com/news/how-many-gallons-of-fuel-d... [3]https://www.batterydesign.net/zeekr-140kwh-catl-qilin/
https://www.sciencedirect.com/science/article/abs/pii/S09575...
https://old.reddit.com/r/electricvehicles/comments/1m8wlou/e...
To power your house (or, more generally, supply vaguely sine-wave like output at a constant voltage), you need a converter that will convert DC at the battery voltage to AC at the desired voltage. If a buck converter is used, for example, the AC voltage can only ever be lower than the battery voltage. If you use a cheap square wave inverter, it’s possible that the output and input voltages must actually be equal.
A motor, though, is a highly inductive load, and large motors will and do operate from truly gnarly supply waveforms as long as the current waveform is approximately correct. Industrial VFDs (variable frequency drives) do unspeakable things involving switching a DC bus voltage across the motor via H bridges at tens of MHz, which is a horrible thing to do the the wiring between the drive and the motor if it’s not extremely short. (There are, recently, some guidelines that specific types of wire with twisted conductors, better than average insulation, and high quality shields should be used to improve tolerance of the fact that rather impressive standing waves can appear in the wiring if the wiring is a quarter wavelength or longer.). I can easily imagine designing a VFD that works just fine over a respectable range of DC input voltages by adjusting its duty cycle accordingly.
One way to think of this is that a VFD looks kind of like a buck converter where the inductor is free in the sense that it’s already right there in the motor. If it’s designed right, it will handle the battery’s full voltage range, and the inductor will still be free :)
I imagine it's not the waveform or current that matters so much, as the voltage. These motors would be powering massive blades encountering incredible resistance, so you need megavolts to move them, with an input voltage all the way down to near zero.
> H bridges at tens of MHz
Imagine the MOSFETs on this thing! Do they have something that scales up to MV? That sounds like an engineering challenge in itself.
Full disclaimer: electronics is not my wheelhouse, though I have played around with motor controllers.
Assuming two days available to charge the vessel, you'd need about 100MW continuous. Not trivial, but doable.
As far as battery fires go, sure, but a) there are already a lot of electric ferries in service so designing safe maritime battery packs isn't a new challenge and b) the alternative isn't exactly risk free either; we've seen plenty of oil spills from ships.
I can only imaging how hard it is to put out a ship fire, but is there any reason to see that the situation would be different? Bunker fuel appears to be less flammable.
Petrol cars at most marginally more likely to catch fire, if at all. They cannot catch fire by simply being submerged in a foot of water, like an EV can. They are far easier to extinguish than EVs, which are practically unextinguishable and can reignite weeks or months later. You can use a fire extinguisher on a petrol car fire if you catch it early (they are usually electrical fires). If you catch an EV fire early, your best course of action is to run away as fast as possible.
Ships are not known to be subject to fires because the types of fuel they use are not generally so volatile, and they are literally surrounded by water which can be pumped to the deck or wherever to drown any fire. Some use diesel, which is difficult to light even with a match. Others use heavy crude oil that looks like tar and would be similarly difficult to ignite accidentally. A battery fire on a ship would be a HUGE problem, as we have seen with ships carrying EVs.
I think another often-overlooked risk of EVs is the arson risk. Even if batteries are less likely to catch fire (in the first few years of use, if you baby them), a bad actor can start an unextinguishable fire by shorting out or otherwise igniting a battery pack. This is easy to do and devastating.
“An American insurer found that just 25 out of 100,000 EVs suffer fire damage.
By comparison, 1530 per 100,000 ICE cars experience fire, and hybrid vehicles suffer a much higher risk of 3475 per 100,000 .”
https://www.autocar.co.uk/car-news/electric-cars/how-much-fi...
As I said, the fact that these fires can't be extinguished is a major arson risk, as is their toxicity. Insurers will eventually have to raise their rates to cover the extreme risk posed by EVs. https://www.himarley.com/news/ev-charging-fires-are-rare-but... Storing damaged EVs safely means you need to spread them out like a hundred feet apart or something, so that one of them igniting doesn't start a whole lot of EVs on fire with toxic and inextinguishable flames. There are no solutions to these problems after having EVs on the market for several years, because it's a very hard problem to solve.
Using containerized energy that can be offloaded and charged and swapped at ports is much more efficient way to spread the cost and infrastructure and safety around the world.
There are many ports where you really don't want any form of radiation/nuclear materials available.
You power this the same way you power aluminum smelters - you have a big honking grid connection and build the generation capacity in places with more room.
If they were all electric, all of this size, and required a full charge on arrival, you’re talking about (very roughly) 1 GW continuous power requirement for charging the ships. That’s a lot; no bones about it, but it’s not unprecedented - aluminium smelters and data centers are similarly hungry for power.
Fire hazards are there for any fuel, Safety systems evolve to handle them. The environmental impact would be more localized than an oil spill.
Is bunker fuel energy density just that bad or is it something else? A 50kg tank of diesel can easily outperform a 200kg pack of batteries in an ev.
You can bunker anywhere, even at sea if you're willing to pay. Ships have large tanks to allow for economically advantageous bunkering at cheap and low-tax ports.
Shanghai to Los Angeles is more than double that
Shanghai to LA is probably the worst example (since the pacific ocean is basically the emptiest spot on the planet, as land/port frequency goes), but Hawaii still exists and they could recharge there.
EDIT: Seems like they mostly use imported oil, so saying "bring us a bunch of oil and we'll charge your batteries with it" seems like the ship is just burning oil with extra steps.
Los Angeles port already tries to achieve zero-emissions operations by 2030 I presume more solar could be added. And I guess some/many ports and Los Angeles specifically could use wave energy. But, again, I could very well imagine Northern Australia supply ports in Eastern Asia.
How?
A grid can do it too, but spiky 400MW loads are difficult and annoying for a utility. And the port, who would probably have to call in to schedule charging.
It's much easier to "trickle" charge a grid scale battery bank, which can then be used however the port wants whenever they want without upsetting the grid.
I wonder what the "trickle" power requirement is? Knowing next to nothing about shipyard logistics... 20MW?
It likely will depend on patterns of harbour. Like how many ships visit, what sort of distance those go. And how much of total time is spend charging some ship.
Worst case is maximum distance trips and maximum utilization that is there being ship almost always being docked. Apart from times when docked ship change.
Ports can have 10+ container ships at once and unloading one can take multiple days. You're not surprising the power company with sudden loads, you're building a big power plant at the docks and then selling power to the grid during the part of the day when the price is high and charging the ships when it's low.
These kind of infrastructure is not something you can build in 3 year. You need more than one port having that.
The battery capacity you have calculated needs about 500 shipping containers.
A large shipping vessel carries 24000 container. So make the batteries containerized, and easy to load/unload.
You could imagine pretty fast charging like this, and at some point in the near future using the same infrastructure with containerized nuclear reactors.
https://world-nuclear.org/information-library/nuclear-power-...
Even if you built one, as some people have proposed designs, it doesn't get you nuclear reactors you can just stack up on a ship or something. Containerized reactors could be convenient for getting a reactor to a remote site where it's needed but once there you'll have to provide substantial shielding for it; usually the way this is meant to be done in these proposals is digging a big hole and/or putting up earthen berms around it. And those earthen berms will be subjected to a lot of neutron radiation, so you need a plan to deal with the site after you run this reactor for any substantial amount of time; the whole site will be radioactive.
There's really no getting around this, and most of the people pitching container-sized nuclear reactors are hoping investors don't realize it. The amount of shielding that you could ever hope to place in an ISO container isn't anywhere near enough.
Nuclear submarines and aircraft carriers already exist in pretty good numbers.
And the proposal was a containerised nuclear reactor, so you're going to irradiate the surrounding containers in the process.
Nuclear submarines and aircraft carriers are completely different beasts. The reactor core is very heavily shielded, is built into the ship/boat, and is tended by a team of expert operators, and (at least in the case of US/UK subs) uses bomb-grade uranium as fuel.
1. I'm ball-parking an onboard nuclear source would take up the equivalent displacement as 20-50 containers.
How many kwh are you lifting at a time with a container? How many kwh are you pumping in the same period?
You can imagine this needs solving pretty hardcore optimization problems.
Ships deliberately use cheaper, less energy dense petroleum products (heavy fuel oil), for pretty much the inverse reasons why airplanes use kerosene.
Planes run on kerosene because it's universal enough, hard to run them on heavy fuel, and there is issue with high emission of the HFO over population centers which isn't as much of a problem in middle of sea
A completely optimized high capacity cargo rail line can move 500 rail cars per hour. That's 1000 FEUs if we double stack containers. A lithium battery system in a FEU has around 2 MWh of storage. So that rail line has 2 GW transmission capacity if we saturate it with batteries - the same as a single high voltage transmission line. Being unable to build one of those in parallel to the rail line would be extremely sad.
Note that 500 rail cars per hour is actually an impressive feat of logistics. A normal rail yard at a port would be very happy with a sustained rate of 200 rail cars per hour, and will frequently drop below that.
In a perfect world however... endless cooling water unless they're in some shallow harbor. Would be the perfect application.
Still not, because all it takes is one thing going Seriously Fucking Wrong on another ship and boom, you got yourself a nuclear disaster. Just look at the Francis Scott Key Bridge and imagine that that ship hadn't hit a bridge support but a nuclear powered vessel.
Nuclear powered ships only make sense for ships operating in places where there is no other ship in sight for hundreds of miles (i.e. icebreakers) or for military ships that can and will shoot and sink anything with the potential of becoming a threat.
https://en.wikipedia.org/wiki/Russian_floating_nuclear_power...
Even navies are moving away from nuclear power due to how expensive it is.
- Weight is less of a limitation than you would think. Ship size is measured in tonnage. 40K-60K is a medium sized cargo carrying ship. So lets assume a ship like that.
- Battery weight calculations are going to be key. If you assume 170 wh/kg, 6 tonnes of battery equals about 1 mwh of battery.
- Energy usage of ships is speed dependent and it's a non linear relationship. You can save a lot of energy by going a bit slower. Going about 15 knots, a ship like this might use 15mw of power.
So the math becomes something like 6 x 15 = 90 tons of battery per hour. 5000km is about 2700 nautical miles (1 knot == 1 nautical mile/hour). So, you need about 180 hours of battery. Or about 16200 tons for a total of 15mwh x 180 = 2.7gwh of energy. That's a big battery.
The real limitation here comes from the cost of the batteries, which is dropping fast with sodium ion. The reason CATL is bringing this up is because they've been doing similar math with some informed $/kwh math. If they can get it down to around 20$/kwh, a mwh would cost 20K, and a gwh would cost 20M. So the battery would cost 54M$.
The key here is that this is still assuming 15knots. Energy usage might drop considerably if you drop it to 10 knots or even lower. You might only need 7200 tons of battery at those speeds.
The ship can handle the weight either way, though you are sacrificing useful load of course. The real constraints here are cost and speed. You pay a fat premium for a fast ship. Of course ships this size aren't cheap. A few tens of millions is normal. And they burn through many millions worth of fuel per year too. So, even though that amount of battery is expensive, the math might actually work out to these ships being cheap enough to operate that they'd earn back their battery.
You'd have to be pretty bullish about cost and performance of batteries. But CATL clearly feels that way. They have several battery chemistries at their disposal with higher densities (and cost). Over time, batteries might get cheaper and more dense. Ship designs might be optimized for batteries (e.g. structural hulls with battery). There's a lot of wiggle room here. But it's not an impossible proposition.
You'd probably want to use a mix of local wind/solar power and a grid connection. Of course, harbors usually already have lots of infrastructure to power heavy industry (steel, refineries, etc.) and transport (e.g. rail). This just adds to that.
There are also other solutions including using container batteries and simply swapping in fresh ones. Which especially in a container harbor shouldn't be that big of a deal.
TL;DR marine is the one niche where "we had to make it a lot bigger to hold the batteries" isn't actually a big deal. If you do this the right way, you still have heaps of volume for cargo, and solar cells on the hold covers.
If you expect _oceanic_ ships in 3 year, you need to start building infrastructure today, in multiple ports.
If you need to build those infrastructure today, you need to have something standardize.
otoh, if all you want are just some prototypes, we have them today already..
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