Is it possible for ocean vessel to generate from sun panels as much as needed for moving? I would suggest vessels does not need scarce Lithium, it is too needed for some other uses.
Cars have regenerative breaking which is a help in urban areas.
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.
I guess I want to know "oceanic" means in this instance. Is that just going out into the ocean a short distance? They mention the "Yangtze River Three Gorges 1" river cruise ship as an example. This thing has a range of like 100km. It seems we are far away from making true oceanic crossings of any long distance and I doubt that is coming by 2028.
I did some fast back of the napkin math on the idea of sahara solar + electrified shipping + sodium ion batteries. A lot depends on the, as yet, fully disclosed pricing of sodium ion batteries but the trend in pricing, and capacity, is clear and the price point may have already happened to make this viable. One thing is clear though, even if my napkin math was massively optimistic and it isn't economically feasible now it will be shortly and at that point energy production around the world is potentially disrupted. Ships can pull in and feed the grid directly or offload containers and onload empty ones to make the trip back for cheap, clean, renewable power. It is looking more and more viable to ship electrons like we do for oil and that is a major game-changer.
* 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 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.
Thinking of charging is also interesting. What is the power requirement for that? If they use 40MW under operation, it means they must charge faster unless they spend at least as long time charging. So that capacity requirement can get quite high.
Okay based on your calculation, here's a neat way to do this.
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.
Not really, kerosene is pretty close to heavy fuel oil on density.
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
Ships sail at the cost of static resistance in water. Larger ships are more efficient, once buoyant. There is a New Scientist story about a guy on guard duty moving a moored navy boat by leaning on it, for a long period of time.
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.
It would be amazing if they could leverage the container system, but instead of goods, there'd be battery containers they could just plug in to the ship. You could even charge a battery container somewhere and bring it in by (electrified) rail.
The germans tried that in the 60s see https://en.wikipedia.org/wiki/Otto_Hahn_(ship).
It was uneconomical.
You need specialized engineers for that, you need special permissions for ports and the important canals are off limits due to risk.
Here's some back of the envelope math for batteries and ships:
- 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.
What you are suggesting in the best case is completely uncompetitive with current ships both in terms of weight and cost. Even the charging costs for 1GWh is absurdly high compared to Heavy Fuel Oil. An orders of magnitude more expensive.
Not to mention dedicating 15-20% of deadweight tonnage (and a higher percentage, maybe 30-40% of its gross tonnage) would make a ship instantly uneconomical, especially as the batteries must be laid along the keel for stability, meaning the ship loses the ability to carry many cargoes.
What's possible in the medium term are Heavy Fuel Oil/Electric hybrids that use battery power in regulated Emission Control Areas instead of Low Sulfur Marine Fuel Oils or Diesel, and using HFO in blue waters and to charge batteries.
Transoceanic battery-powered cargo vessels are probably 100 years away - fusion will arrive first.
If your average solar array gives 2.5MW per hectare then 15MW would require 6 x 100m x 100m to run, or a beam of 150m for a 400m long vessel (eg Evergreen G-class.)
That’s only ~4x wider than the current big classes of ship. Maybe we will see twin hulls with a solar field slung in between?
The downside of course is you can no longer romantically sail by starlight (or at least, technically, by the starlight of non-Sol stars.)
The upper weight limit for both 20ft and 40ft shipping containers is around 28,300 kg. Since SodiumLion batteries in containers will be weight limited, it makes sense to use 20ft shipping containers. One container can probably store around 3MWh of energy. For a 2700nm trip at 15 knots with 15MW of power usage, you need 2700Mwh divided by 3MWh per container gives us 900 20 ft shipping containers (TEU) for the battery.
OTOH if we look at popular shorter range routes like within Asia or Europe the calculation looks a lot more favorable.
I've wondered if thermal storage might be superior. Lower round trip efficiency if one uses resistive heating, but I think that would be ok.
Lithium hydride, heated to melting, stores something like 4 MJ/kg, more than 6x the specific energy of your assumption there (admittedly with loss on discharge due to the losses in the turbine.) If that is too expensive, graphite is another possibility, at even higher temperature.
Those are some big numbers. It makes me think of a crazy thought experiment:
How many MW could a container ship carry by literally shipping energy stored in batteries?
As in they fill up entirely with batteries, sail to a desert, plug into a cable to charge on cheap solar, charge up, sail to a population center, plug in to discharge. Repeat.
If we could only complement that battery with a small nuclear reactor, then we'd be in business.
Come to think of it, shipping would be quite interesting for a SpaceX style disruption - there is a market for many many thousands of units - enough to actually get good at building them in a repeatable fashion.
Of course there are considerable engineering and political challenges, to put it mildly.
Sails [0] [1] [2] are obviously more sustainable than the gigantic industry needed around batteries this size. That'd of course massively increase the cost of shipping and suddenly producing most things locally would make more economical sense. Bye bye £2 jeans from Shein.
Since there is a lot of space out there in the ocean I wonder if some kind of big floating energy station could be a thing, using middle of the ocean wind, tidal or solar. I guess you don't have to pay anyone for the space or worry about too many regulations etc.
I like your idea. We can now generate substantial amount of power from floating wind turbines. Coupled with floating batteries (ie on cargo ships) we perhaps build floating charging stations along major shipping routes. There is no need for nuclear or to only charge at ports. Would it work?
Clusters of floating wind turbines each with their own battery storage might be useful here. I imagine along strategic (ie major) shipping channels. Would it pencil out? I have no idea.
39 comments
[ 0.17 ms ] story [ 76.0 ms ] threadShips 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.
Allseas is putting the reactors on their vessels as well iirc.
* 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 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/
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.
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
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..
- 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.
Not to mention dedicating 15-20% of deadweight tonnage (and a higher percentage, maybe 30-40% of its gross tonnage) would make a ship instantly uneconomical, especially as the batteries must be laid along the keel for stability, meaning the ship loses the ability to carry many cargoes.
What's possible in the medium term are Heavy Fuel Oil/Electric hybrids that use battery power in regulated Emission Control Areas instead of Low Sulfur Marine Fuel Oils or Diesel, and using HFO in blue waters and to charge batteries.
Transoceanic battery-powered cargo vessels are probably 100 years away - fusion will arrive first.
That’s only ~4x wider than the current big classes of ship. Maybe we will see twin hulls with a solar field slung in between?
The downside of course is you can no longer romantically sail by starlight (or at least, technically, by the starlight of non-Sol stars.)
OTOH if we look at popular shorter range routes like within Asia or Europe the calculation looks a lot more favorable.
I've wondered if thermal storage might be superior. Lower round trip efficiency if one uses resistive heating, but I think that would be ok.
Lithium hydride, heated to melting, stores something like 4 MJ/kg, more than 6x the specific energy of your assumption there (admittedly with loss on discharge due to the losses in the turbine.) If that is too expensive, graphite is another possibility, at even higher temperature.
How many MW could a container ship carry by literally shipping energy stored in batteries?
As in they fill up entirely with batteries, sail to a desert, plug into a cable to charge on cheap solar, charge up, sail to a population center, plug in to discharge. Repeat.
IMHO a hybrid approach would achieve similar to superior perfomance to the current state viz a viz cost/perfomance and enviromental impact.
Additionally as has been deployed for some longhaul trucks battery swaps can also cut down on the time to redeploy after offloading the cargo.
[1] https://gcaptain.com/berge-bulk-launches-worlds-most-powerfu...
[0] https://www.towt.eu/en/home/
[1] https://www.neoline.eu/
[2] https://graindesail.com/fr/voilier-cargo-grain-de-sail-3/
* https://en.wikipedia.org/wiki/Combined_diesel–electric_and_g...
* https://en.wikipedia.org/wiki/Combined_diesel–electric_and_d...
* https://en.wikipedia.org/wiki/Integrated_electric_propulsion