Technology
This is the official technology community of Lemmy.ml for all news related to creation and use of technology, and to facilitate civil, meaningful discussion around it.
Ask in DM before posting product reviews or ads. All such posts otherwise are subject to removal.
Rules:
1: All Lemmy rules apply
2: Do not post low effort posts
3: NEVER post naziped*gore stuff
4: Always post article URLs or their archived version URLs as sources, NOT screenshots. Help the blind users.
5: personal rants of Big Tech CEOs like Elon Musk are unwelcome (does not include posts about their companies affecting wide range of people)
6: no advertisement posts unless verified as legitimate and non-exploitative/non-consumerist
7: crypto related posts, unless essential, are disallowed
view the rest of the comments
Still doesn't really seem all that big. Some EVs have 100 KWh batteries. A container ship with the battery capacity of 500 cars doesn't sound like much.
Until you realize that the energy requirement is also different. Land transport in general is very inefficient. Ship is in fact one of the most energy efficient means of transport.
I don't disagree but every time I've seen a diesel engine on a cargo ship it was absolutely massive.
Size wise, it is small relative to the ship size. Look at car engine. How many % of volume is taken up for the engine and fuel tank of car? I think it is close to 30-40%
194 nautical miles isn't terribly far, though. For port to port, sure. For oceanic shipping, I don't think 194 is going to cut it. I think we will probably have to do SMRs or efuels to really cut cargo ship and cruise ship emissions when crossing the Pacific or Atlantic. Though I don't know where nuclear powered shipping (in non-military applications) is in terms of progress.
I do think that cargo ships are the one vehicle where solar panels would make sense though. Add that and a sail, and you should be able to increase the range considerably.
Ships are much more efficient than cars. Having said that, this wouldn't have a huge range, nor is it terribly big by container ship standards.
Add sails and solar panels and its quite a lot
Yep, and the Chevy Silverado EV manages 200kWh now. This cargo ship better be small and efficient because 250 American pickup trucks worth of battery really isn't much.
A cargo ship is probably more energy efficient than an American pickup lol
It's still not a lot of energy though. Some rough napkin math for how far this would get you is below:
Typical medium size cargo ships in the Panama Canal travel around 25 knots burning 63000 gallons per day of fuel with 5000TEU of cargo. That's roughly 600mi/63000gal or 1142miles per ton gallon. That Silverado EV somehow weighs 4 tons (totally safe to be driving at highway speeds), so this is the equivalent of roughly 285.5mpg per Silverado. The Silverado is 67mpge on its own, so the ship is just over 4x as efficient (and slower which is ignored here but would impact the vehicle efficiency).
So using the Silverado's 450 mile optimal range we can say it has at most an optimistic 7 gallons equivalent fuel in its 200kWh battery. 50 MWH would be enough for a theoretical 1750 gallons equivalent if efficiency were the same. But for the efficiency difference this corresponds to a 4.2x improvement to 7350 gallons equivalent. Therefore this is enough to run that typical ship above for 2.8 hours. So with 65000 tons of cargo in the above ship to do a 200 mile route this ship would need roughly 3x as large a battery. More likely it will just carry ~1/3 the cargo or have charging stops en-route.
The 19.4km/h top speed of this ship suggests they're well aware of the extremely limited range this will have for its size and it sounds like the Shanghai to Nanjing route will be pushing it's limits despite being less than 200 miles.
You took the worst possible path to calculate all of this. Just compare energy to energy, that's the whole point of Watts.
True but efficiency is not the same and not as simple to compare since we don't know how much of the ship's battery is converted into motion. Similarly we don't directly know it's mass. ICE cars can use ~20% of the energy in fuel while EVs 90%+ of the energy in a battery. But now much can that ship effectively use? I have no idea how efficient boats are or aren't, hence the roundabout method above.
I bet that cargo ship can only kill two, maybe 3 pedestrians on a good day. 250 american pickups could do that in an afternoon.