62
votes
A cargo ship equipped with rigid sails, each the height of a ten-story building, has departed on its inaugural journey
Link information
This data is scraped automatically and may be incorrect.
- Title
- Hard sail test hits the high seas, aiming to reduce cargo ship emissions by 30 percent | Engadget
- Word count
- 449 words
The ship in the article doesn't have any containers on it. How would this technology be used in a ship with 20,000 containers stacked at least half as high as the sails are built? Is it possible to build the sails so high above the containers that they can still meaningfully harness the wind? The image I have in my mind is a set of comically high sails. I don't have the engineering background to determine if that's realistic.
I can certainly see this technology being fairly easily applicable to cruise ships.
I think I’ve seen some vertical cylinders that use the magnus effect to reduce fuel usage that are able to work on container ships. They don’t do everything, but 20% fuel reduction is a huge win for emissions.
Check out this industry article about the limitations to putting this on a ship
There are cargo ships that don't move containers. Tankers, ore ships, etc
Yes, that's exactly it. Do an image search for "Cargo Container Ship Sails" and you'll find images showing how that'd be implemented. Either the base is higher or the shaft is taller.
This article is full of near-meaningless marketingspeak and low on actual details, which I guess isn't that surprising considering the source. That said, I heard something about this idea a while ago and it sounded promising, and I'm glad someone's trying it out. Looking at that picture though I have to wonder things like "What do they do with those things during a storm? When they're in port loading/offloading cargo, don't they get in the way?"
Theres a Viking Line ship with a round pylon sticking out of it. Apparently it spins and then magic happens and it helps the ship move. I've read the wikipedia article of how the thing works but I'm too dumb to understand it. Interesting anyways.
It works in tandem with winds/standard propulsion. When air is passing by a cylinder, it would normally curve around it, some what symmetrically. But if you spin the cylinder as air passes by you can create a turbulence that actually assists in propelling. It is almost like how a wing can create upward lift by taking advantage of air moving across it.
E: Ok I found an interesting answer to my question below. Turns out kites are a good option!
https://www.quora.com/Why-don%E2%80%99t-modern-civilian-cargo-ships-also-use-sails-in-addition-to-engine-power-to-reduce-fuel-consumption?share=1
Maybe this is a dumb question, but why don't modern ships already use sails? I mean I get that a of the time it could just cause more drag if the wind aren't favorable, so it'd need to be deployable, but still you'd think that they'd take the free movement when they could given the size of these vessels. Huh, maybe that's it, they can't make sails big enough to really matter for such a heavy thing?
It's not my field of expertise at all, however, for container ships they would get in the way of loading and unloading and make it harder to stack cargo as high as they currently do. Also they might require significantly more crew and skilled crew to work with them. I would love to see sails in use in some practical way. I think it is elegant technology and can be beautiful as well as being clean tech.
I think you're highly underestimating the massive amount of power that it takes to drive a big cargo ship. Solar panels would have to send power to a battery which, even with lithium, would have to be absolutely massive to be viable for holding power for anything but a very short haul.
And solar panels - just some quick math - a 1300 ft Class 3 cargo ship might have two 31,000 kW motors (42,000 hp each). A large home solar panel is rated at 500 watts (0.5 kW), so even if it output at full capacity that means a ship would need 124,000 panels to power it continuously. Each panel is about 28 sq. ft so that's 3,472,000 sq ft of panels. If the ship is 1300 ft long it would need panels spanning 2670 ft wide, or about 13 times the width of the ship to power those motors.
And thats only if the sun was shining directly down on the ship 24 hrs a day, which it obviously doesnt. Even if the sun was shining perfectly for 12 hours, the panels would need to double, so 26 times wider than the ship. Not exactly doable.
ps. Someone can check my math. I might be out to lunch.
The reason cargo ships still burn heavy oil is that carbon based fuel contains a lot more kW than solar and batteries ever do.
Let's stick a Thorium nuclear reactor on there and see how it goes :P
Why? You don't need to store that power, just use it. I agree with the rest of the sentiment that solar is just not worth it on a ship but you don't need a battery to make solar panels work.
Then the cargo ship is at the whims of the ocean currents overnight, and/or when it’s overcast or stormy or any other conditions that’s not clear skies…
You do because solar power is not constant. With full sun the panels might produce enough to power the motors at full speed. But the sun goes behind a cloud now they only produce two thirds of that. A really cloudy day they might produce half. And at night, nothing at all. The batteries are there to store power for the low power points and at night.
@gowestyoungman @ThrowdoBaggins
I kind of misread the comment chain. I was under the assumption that we were talking about a hybrid system with diesel generators and electric motors driving the screws. You wouldn't really need batteries in that situation.
Even so, I think you'd want batteries on board, even if only to absorb excess power. As solar power fluctuates the diesel generators would have to spool up and down to keep the power level constant, and that might take a few seconds for large engines. Batteries would help by supplementing power when the sun goes behind a cloud and the engines respond to the drop in solar, then reabsorbing that spike in energy as the cloud moves out of the way.
Fair enough. The leap from lead acid to lithium batteries made a huge leap forward for a lot of tech, but we need another order of magnitude leap in energy storage if things are going to actually change toward greener tech.
The fast chargers (DCFC) take around 30 minutes. The issue isn't that the technology doesn't exist, it's that it's not deployed in our transportation system at the rate gas stations are. That is, the government needs to de-incentivize the construction and operation of gas stations and incentivize electric charging infrastructure.
Clearly, scientific breakthroughs in charging speed would still be welcome, but it isn't a significant inconvenience to take a 30-minute break to eat lunch while the car charges on a road trip.
It is however inconvenient to add a 30 to 45 minute errand to an already busy day, even assuming there isn't a line at the charger. Until charging becomes faster, it's not going to work for people like me who park blocks away from home and don't have dedicated parking at work.
This still sounds like an issue of deployment and not technology. The solution here is just to add more public chargers in places that people park. If your car is parked somewhere overnight, then even if it's not a particularly fast charger, you will have a full or near-full battery in the morning.
So, one at every parking space on every residential block? You are right, that would solve the problem. The investment would be massive, but ok.
I don't know about every parking space (there are like two billion in the country), but how many cars can conceivably fit between two telephone poles on a typical street? Four? String up a couple outlets with a meter to each pole, — this infrastructure is already being used to transmit electricity, so it's not a huge stretch — and there you go. It's not like regular parking meters are a novel invention! This would cost money, but not nearly as much as installing DCFCs everywhere. The chargers don't have to be fast, they just have to exist. Most people don't drive more than 30 miles in a day.
This would only be strictly necessary in fairly dense areas where people park on the street because their homes or businesses don't have garages. In low-density residential areas, it isn't a problem. In those places, people choose to park on the street instead of in their electrically-equipped garages for reasons I cannot divine, so the municipality isn't obligated to cater to them.
The real answer is to manufacture locally and not in China so that we don't need nearly as many cargo ships
I think the only feasible way to replace fuel oil ships is going to be green hydrogen, which have had several new plants opening up to produce
I think ships are already electric drive for the most part. But they don't run off battery, instead driving the motors directly from the generators.
No, they are not electric drive, they're IC engine with a regular crankshaft for the most part and plenty use two stroke motors.
Seems there's conflicting information out there. This article claims 80% of cargo ships are diesel electric. https://www.resilience.org/stories/2022-07-28/making-waves-electric-ships-are-sailing-ahead/
I find that very hard to believe but I admittedly am only tangentially related to the marine shipping space.
Something to consider is that "80% of cargo carriers" is a bit of a vague metric since it does not concern itself with tonnage. One 100000MTS vessel is not the same as ten 1000MTS vessels.
Understood, but my point was originally that there's a lot of ships out there that are already electric drive. Those ships are going to be easier to retrofit with more electric generation options, though no idea how difficult those options would be to integrate.
Except for the article you linked I can't find anything supporting the 80% electric drive but I can't find anything definite on the actual % either, just vague insinuations that "this new thing might catch on".
If it's diesel-electric then that's it, it already has generators, solar panels or other methods would be negligible for the power requirements of large vessels. For reference, in the 60-100000MTS range the consumption is between 20 and 30 tons of fuel per day when sailing.