The Return of Sail Power: Cargo Ships Are Turning Back to the Wind
gcaptain.comNo, they’re really not.
Turns out, sail-power scales sublinearly and, shocker, the wind isn’t a reliable source of power for the logistics demands of today’s supply chains.
We’re never going back to wind, but we will be de-carbonizing shipping either with ammonia combustion, fuel cells, or both.
If you had bothered to at least skim TFA, this is addressed in the third paragraph:
> The idea is not to turn modern cargo ships back into sailing vessels. Instead, these systems are designed to work alongside conventional engines, using the wind to reduce fuel consumption whenever conditions allow.
News articles to this effect have been popping up occasionally for the past 20 years at least. So the economics don't seem to stack up. At least not yet; but if oil gets a bit dearer...
They really are being built and used commercially. Probably incentives play a part in this, but their numbers are slowly increasing, so it's not totally vaporware (of course we don't need new articles every ~6 month talking about how amazing this technique is) [0]
I think news publishing has recurring schedule for topics for filler articles, and this is just the regularly scheduled appearance of Flettner rotors.
I saw the headline, and immediately knew what it is. Always the same: headline implying sail power is back, body correcting that it's about minor fuel savings, and that some shipping companies are planning to install rotors on their fleet.
"The International Windship Association says more than 100 large merchant ships are now equipped with modern wind propulsion systems, representing more than 5 million deadweight tons of carrying capacity."
It's not much, but it's more than just planned stuff. I do generally agree with your sentiment.
Somewhere in a cube farm that hasn't been updated since the 90s:
"This month's analytics report indicates our college educated white collar employed left leaning traffic to our properties is down over the same month last year"
<puffs vape>
"Don't worry about it, I'm having AI re-write all the green tech articles from 2005-15, it'll be back by November"
Agree that it's not going to be a binary shift. The tech does look promising for at least rotor sails, but that's an improvement which also demands use of traditional powerplants to drive the rotors ofc. Still worth investigating imo considering the shipping industry is the area of the world that still contributes highest to carbon output and is sort of an "untouchable" industry due to criticality. If cheap enough this could help while we wait for e.g. "greener" fuel or other things to develop. But yeah, to underscore further, not like shipping will look like my sailing yacht any time soon.
Longer term I think we'll also use synthetic liquid hydrocarbon fuels manufactured through the Fischer–Tropsch process. People have proposed bringing back nuclear powered merchant ships but that's a non-starter for cost and security reasons. We can keep the nuclear plants safely on land and use them to make carbon-neutral fuel.
That is insanely inefficient however. It only makes sense for transoceanic air travel, probably supplanted by synthfuel from biomass, but in the long term we will see ships powered by batteries. Far far more efficient.
Batteries are already being used for ferries but they're too large and heavy for transoceanic merchant ships. I doubt that operators will be willing to make more frequent port calls just to recharge.
... at the moment. We might find ourselves with containers full of batteries being exchanged on sea by feeder ships. Doesn't help across the real oceans, but works along coastal routes (which Asia-Europe definitely is).
The more expensive oil is, the faster the transition will have to be done. Simply because at some point, even the trash that freight ships burn will be more expensive than a bunch of battery containers and an electric drivetrain.
Oil will not stay expensive for a long time without some carbon tax. Even if Hormuz will remain closed for years production will rise elsewhere. The main reason production is not increasing significantly right now - investors are not sure that prices will stay at the current level for a long time (3+ years) and expect prices to fall before they’ll get enough to recoup investments. The longer prices will stay around $100 the more will be invested into new oil wells.
I think it’s clear that they are not turning back to use them exclusively, but clearly are ‘turning back’ in an additive way.
Eg putting these things on ammonia powered vessel will reduce the amount of fuel needed, which is probably a net benefit.
We're not going "back" to wind, but there are vessels with modern sails already deployed to save a couple of % fuel costs. There were 9 in 2020 and are 64 now, according to Sintef. Of course kinks are still getting ironed out, but it seems likely it will continue to grow.
Couldn't they use sails plus that? Are these companies advocating for just sails, or sails plus other stuff?
Sails plus the regular engines, for a % in fuel reduction that adds up at scale.
That’s exactly what they’re doing to reduce fuel usage by up to 6%.
I think it's up to 24% for rotor sails,no?
And yet:
~ (September 16, 2026) https://www.watoday.com.au/national/western-australia/high-s...Klaveness Combination Carriers (KCC) has launched a brand-new vessel that aims to use wind technology that the company believes will not just reduce emissions, but also improve fuel efficiency on its voyages between China and Australia. Equipped with the first wind-assisted propulsion system in KCC’s fleet and a range of advanced energy efficiency technologies, MV Baltazar was officially launched at Fremantle Port this week .. According to the company, due to the ship’s trading area, size and advanced energy efficiency measures including suction sails, MV Baltazar has the lowest carbon footprint of any vessel in these trades.> de-carbonizing shipping either with ammonia combustion, fuel cells, or both.
Or methanol:
* https://methanol.org/what-fuels-shippingMethanol is emerging as one of the most practical low-greenhouse gas (GHG) fuels for deep-sea shipping.* https://www.dnv.com/maritime/publications/methanol-fuel-in-s...
* https://www.lr.org/en/knowledge/research/fuel-for-thought/me...
> methanol
Currently made from crude oil in a CO2 emitting process from a finite fossil fuel resource.
And yes, whilst methanol can be distilled from wood/crops (a more expensive process), this simply cannot scale, especially if humanity wishes to eat...... You do realise a large container ship is 1/4 mile long and carries north of 18,000 TEU containers; that's 9000 lorries worth. They are big.
> Currently made from crude oil ..
Much of it is, just like ammonia (see comment I responded to) but green methanol ships have been trialled using output from pilot green hydrogen plants.
> You do realise a large container ship is 1/4 mile long
People still use miles? Wow. I'm more familiar with the shipping of a billion tonne of iron ore per annum from the NW Australian coastline in bulk carrier ships but please, do blather on in that condescending tone.
> green hydrogen plants.
Splitting fresh water (salt water is a non-starter) for hydrogen is a rather energy inefficient and expensive process.
> People still use miles?
In maritime world, yes we do; nautical and statute.
> do blather on in that condescending tone.
I do appear to have touched a nerve old sport.
How about the equivalent of an space elevator turned 90°:
Can we built giant conveyer belts across the ocean?
Ships are ~5x more efficient than trains so unlikely a good trade off. It would have to be a maglev to beat shipping.
transpacific zipline (don't tell musk he might start a company)
s/start/buy
ftfy
Get rich quick scheme with the catch that you'll have to deal with Musk?
Guess I'll pass
Aren't the wind turbines & solar parks fucking up our landscapes ugly enough you dolt?
If anyone else was confused why those pictures were of giant tubes and not canvas sails, you are not alone. Apparently those are some version of "Suction Sails". The vendor's website has a graphic that explains it, though it was fighting my ability to scroll.
Possibly https://en.wikipedia.org/wiki/Rotor_ship ?
Most of the sails in the article seemed to be rotor sails, but the suction sail mentioned by GP seems to be a type of turbosail.
interesting that the rotor sail principle can be used with planes too:
https://en.wikipedia.org/wiki/Magnus_effect#In_aviation
(can't help but think "tilt rotor" of a different kind)
The rending of the Maersk ship really strains the concept. If the containers are stacked that high, would it not block the wind going to the solitary sail?
The force is perpendicular to the sail.
That is not how I read the article you linked. It says the force is perpendicular to the long axis AND airflow. And later it says the force is perpendicular to the wind.
So I am reasoning with a side wind 'on the beam' you get a force pusing forward. Which incidentally is a traditional rigs best point of sail. This doesn't appear to be the full story, since the boat in the photograph is healed over in the same way as the gaff rigged sailboat next to it, so there appears to be some sideways force too. Laterall resistance of the hull in the water will force that into a resultant force that is mostly forwards (but with some leeway) I presume.
I am supossing that when running before the wind this means the force is to one or other sides of the ships axis (depending on the rotation). The resistance of the hull to lateral motion forces this again into forward motion. But the sail is indeed being obstructed by the containers and I believe the force will therefore be diminished as per the OP, since the wind has led sail area to act on.
I am inferring all this since the wiki is light on detail.
I would be concerned that one cannot reef this kind of sail. In a storm it is going to heel the boat more, change its motion through the waves, perhaps press the bow down. Bearing in mind that on a traditional square rigger, one would lower the top part of the mast before a storm to reduce windage.
I feel a better reference would be an aid... but I'm with the op, at some points of sail the containers are in the way
I attempted to say perpendicular to the wind and failed.
Same principal that causes a soccer ball to bend. The magnus effect.
There are two visually similar sails. Some are rotating tubes that generate lift via the Magnus effect and even though they create low pressure zones, those are not “suction sails”, strictly speaking.
A suction sail is a more or less conventional airfoil that houses an axial compressor to basically suck in air which causes the boundary layer to stay attached which generates lift via the same mechanisms as an aircraft wing.
From a distance and to a casual observer they’re pretty similar.
The article did mention suction sails for the Maersk Tankers, but it does seem like the bulk of the article was about the rotating tubes.
59 different companies including mine responded to MARAD's recent RFI on nuclear powered merchant ships. Many people are realizing that wind, hydrogen, ammonia, etc are falling short for global scale shipping.
https://www.federalregister.gov/documents/2026/05/07/2026-09...
TBH this makes the most sense. Nuclear for large scale shipping + battery electric or hydrogen for smaller distances, rivers etc.
Sat next to a fusion researcher once on a commuter train.
This particular line struck me: "When oil prices go up, so does money for fusion research"
Feels the same for sail and cargo ships.
The most recent example, it's somewhat down the page at the gcaptain URL:
You can also sail on the Neoliner Origin as a passenger if you want to get a closer look: https://www.sailcoop.fr/en/our-crossings/north-america/
This seems to happen once every 20 years.
Yep. They alternate decades with the 'Airships are returning for cargo' groups.
I'd be down for a future of awesome looking ships and giant zeppelins gracing the sky.
I'd love to fly in a Zeppelin, too, but the problem is they are very vulnerable to the weather.
AIUI the problem is the economics are pretty unfavorable for smaller-scale prototypes due to square-cube issues (drag and thus fuel costs is proportional to cross-sectional area, lift and thus cargo capacity is proportional to volume). You'd need a very big airship to get a competitive economic niche between sea and traditional air freight, where you're faster and more flexible than sea transport and cheaper than traditional air freight.
Hmm. Couldn't you put solar panels on top for power (and fly above the clouds) + use some sort of sail when wind is available? It might be really slow, but if you can get the systems to be fully autonomous (no people needed to pilot it) and need very little / no fuel... then couldn't it become a rather cheap way to ship things that aren't urgent?
Solar panels don't have good enough power to weight ratios and aren't likely to contribute effectively.
As far as sails go, you need a second medium to act as a keel, otherwise it's impossible to get a net push in any direction other than downwind.
There is another niche if you make them several miles long and width. Then can use more conventional construction materials like a concrete shell. (We are of course not ready for that)
To date, they've achieved a very high level of advancement in making a new airship that looks like a butt. Sir Mixalot would be proud.
https://www.google.com/search?client=firefox-b-d&q=airship+t...
Soon we’ll need to provide proof-of-age just to look up at the sky.
I feel like I've seen that same thing for 20, 30 years now, lol
A very recent xkcd touched on this:
You mean once every 20 months. I've seen this article several times already. I first learned about Flettners from one - fascinating devices, btw. - which is why I notice when it resurfaces again, every year or two.
About the same frequency the US starts a major war or oil prices skyrocket for someone else's war. 20-ish years ago was the Iraq 2 war. 20-ish years before that was Iraq 1. Now it's the unholy combination of Ukraine beating Russia's refineries and US/Israel striking Iran.
And the higher oil prices go, the more people are interested in saving oil.
Skysails tried, now they appear to have fully pivoted to land based power generation.
My dream future would see the oceans swarming with kite driven robotic boats that just cruise around under kite power, harvesting electricity with hydrogenerators as they go, feeding that power into a hydrolyser slowly filling some hydrogen storage unit that they drop off for sale at a port when full.
Wouldn't it make more sense to store windpower at sea and transfer the resulting fuel to passing by ships?
I've also thought this. There are loads of offshore wind farms in the North Sea and I bet the cost per kWh at the offshore substation is a fraction of the cost compared to the same electricity once stepped up for transmission through the undersea cables to the shore, possibly curtailed due to grid congestion and then transmitted still further to the urban load centers.
If only there was a reliable, mature process to turn air\seawater plus energy at the windfarm into a synthetic fuel (ammonia or methanol maybe?) that could be then stored and used to refuel green shipping that burned no bunker fuel or diesel?
Why is every paragraph in this article at most 2 sentences long, with most of them being a single sentence?
Gotta adapt to the decreasing attention span economy.
We need to start fitting nuclear reactors on cargo ships.
The technology is proven and reliable. Not to mention no emissions.
> We need to start fitting nuclear reactors on cargo ships.
That's a great idea, and it's timely too. Right now, cargo ships are being attacked in many parts of the world.
If you think about this for a minute, maybe you'll be able to form a theory for why this is already very common for military vessels, but not so much for unarmed civilian ones...
Icebreakers are not military vessels and they have nuclear reactors.
Probably initial cost is the reason this did not become something more common.
Yes, but they're also not regular old merchant ships by any means. All existing ones see to be operated by a Russian government-owned corporation.
Growing up as I did in an old seafaring town, quite near Ahab's ports of call, I love the romance of the sea and I listen exclusively to sea chanties.
For low-value and bulk cargo, ships make sense, and modern computer-controlled sail trim and wind energy harvesting probably makes a great case. But high value cargo is largely today shipped by air. Nvidia wants money for its chips ASAP, too valuable to sit around non productively while being steamered. Maybe with surplus wind energy they could mine bitcoin while en route?
A sort of related topic, about 20 years ago during peak farm-to-table "buy local" fashion, the NY Times pointed out that lamb shipped from New Zealand (where is that on a map, I can't find it?) to New York City arrives with a lower carbon footprint than lamb delivered by trucks from nearby upstate NY farms, such are the economies of scale in shipping.
But now, blow me down me hearties, I look forward to dining on New Zealand lamb carried to my door by the winds of fortune!
Ooh what's your favourite sea shanty, or chanty gang?
https://m.youtube.com/watch?v=BgpBZB3Apno seems appropriate somehow
If there was a direct and maintained electric train route + stronger food regulation in the US you could dine on fresh local produce with a lower carbon footprint.
International cooperation and trade is great, but in the US specifically the economic behemoths have used globalization to paper over the real problems that we face at home (we haven't truly invested in infrastructure in a long time, the meat we produce is rejected on health standards abroad, etc). I doubt the smokescreen will last much longer with Trump et al blowing up international agreements.
>If there was a direct and maintained electric train route
What do you mean by this? Most US freight trains are already diesel electric. German freight uses overhead electric wires on most of the shared passenger rail network, which is great, but doesn’t make it any easier or faster to deliver freight to consumers. Are you thinking of high speed rail? Bullet and maglev trains aren’t used to deliver freight anywhere globally that I’m aware of.
Diesel... electric. Now remove the word diesel.
It reduces the carbon footprint considerably if you don't have to fill up your trains with carbon.
No, you don't need maglev to compete with a ship sailing from NZ on speed.
But you would need maglev if you wanted to compete on energy per ton of cargo per mile. Ships are several times more efficient than classic trains.
NZ is also several times farther.
Look around on youtube how dilapidated a lot of US freight rail is.
I'm German, so I'm well used to dishing out on our railways, but at least our rails don't look like spaghetti that have been way overcooked and can only safely be driven at walking speed. And the amount of black smoke the locomotives emit when spinning up their old engines... wouldn't pass any emissions inspections here in Germany.
US rail is in great shape. You are confusing lines that are nearly abandoned and will be soon but they can take a couple more trips for the state of US rail. US rail is in great shape overall, and very well maintained.
YouTube is not an unbiased source of information, please find a better source before making claims.
American diesel emission standards are famously more strict than Germany's. That's the whole reason why diesel cars aren't as common in the USA, and why Volkswagen had to cheat to pass emissions tests.
Railways have emissions standards different from road vehicles. And VW cheated because they couldn't pass European regulations, the thing is that the big lawsuit took place in the US because US courts allow far bigger monetary amounts.
I'd first question whether the NY Times' accounting included the carbon footprint within NZ, where the lambs are probably raised far from the shipping piers. Then you've got the infrastructure and power requirements for freezing for the long ocean voyage. Then...
After that, I'd question local sheep farmers about how suitable upstate NY is for raising lambs, compared to NZ. And about the regulatory and business environment they face. Agriculture in the US is a hellish mess, and the great majority of its problems are caused by neither its associated carbon emissions nor by underinvesting in transportation infrastructure.
NYers dine on fresh local produce without subsidies or government interference.
Farm fresh vegetable produce is perishable and goes from fresh to wilted/rotten very quickly. It is in the capitalist interest with no regulation to move fresh produce as quickly as possible to the supermarkets and onto the shelves. Every day trucks bring fresh produce from NJ and LI and upstate NY into the city and it immediately goes onto the shelves for sale. No communist system could do it as well.
Produce is an extremely profitable segment of supermarket sales. The markups are very low (no communist could compete) but the turnover is very quick. While a can of beans might sit there a few weeks, customers love fresh produce. So hypothetically, they could make a 0.5% markup (you going to take public transit to NJ to buy produce a half a point cheaper?), but that's every week, so in a year it's a healthy 25% markup for the supermarket's annual investment. I made up the numbers to explain the concept, but that in a nutshell is supermarket economics. Maybe they mark up 2% and the annualized profit is 100%. Tiny margin, healthy profit, point made. Very efficient, happy customers, happy supermarkets.
Trucks bring produce farm to table, maybe a distribution stop. Trains are for bulk stuff and not route flexible, so it's not clear they contribute any advantage to the mix, but I love me trains too.
And it's not just NYer's, that's just an urban extreme example, every supermarket chain the the country operates like this.
Can we bring zeppelins back next for air?