The Return of Sail Power: Cargo Ships Are Turning Back to the Wind
gcaptain.com87 points by gumby 8 hours ago
87 points by gumby 8 hours ago
No, 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.
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.
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.
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.
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.
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.
And yet:
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:
Methanol 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.
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.
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
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
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.
The most recent example, it's somewhat down the page at the gcaptain URL:
Why is every paragraph in this article at most 2 sentences long, with most of them being a single sentence?
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?
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...
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.
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!
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.
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.
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?