[Panino]

> The ships in service show a reduction in fuel consumption, and thus a similar drop in emissions, of between 5% and 25%, says Tuomas Riski, the firm’s outgoing ceo. Each rotor costs around €1m, which he says can be repaid in fuel savings over three to ten years.

> After six months at sea the WindWings have cut fuel consumption by about 15%, although the company reckons three sails could cut average fuel use by 30% or more.

> Oceanbird reckons the sails could deliver 50-60% lower emissions compared with conventional vehicle-carriers.

> Airseas tested a Seawing last year on a k Line cargo ship. They are expected to reduce carbon-dioxide emissions by some 20%, says k Line.

These are consistently good results across a range of carriers. If the industry moved to these sails, the aggregate emissions drop would be significant.

[yjftsjthsd-h]

I think the trick is that assuming everything holds up, it's just cheaper to run. Therefore, if it really works in the general case then the industry will move to these out of sheer naked self-interest unless there are major caveats (I dunno, maintenance issues? Seems unlikely but this is hardly my area of expertise).

[tuatoru]

If demand for shipping is elastic, cutting costs will mean more than proportionately more shipping happens. So will marine pollution be reduced?

[aetherson]

Shipping by container ship is already pretty cheap, and of course shipping isn't itself a good that people care about, it's a way to get some other good. It also seems like the supply bottleneck for shipping per se is probably more "number of ships" or "capacity of ports and big canals" than "fuel costs."

We should of course assume that ceteris paribus lower shipping costs produce more shipping on the margin, but I don't see a lot of reason to believe that this is the major supply bottleneck for most goods. I wouldn't expect to see a dramatic change in demand for shipping as a result of 20% lower fuel costs.

[kefabean]

Jevon’s paradox?

https://en.m.wikipedia.org/wiki/Jevons_paradox

[tuatoru]

That's what I had in mind. Thank you.

[szvsw]

I believe that generally speaking, shipping costs typically are considered a relatively small portion of overall costs for any given product - just going off discussions in Box by Levinson, in which he asserts that one of the paradigm shifts enabled by containerization which allows for globalization to emerge as a phenomenon is that container-based shipping drops the cost of shipping to a negligible fraction of the product being shipped.

Another thing to consider is that the cost to the shipping company goes down, which might just mean they get more margin to keep for themselves, if all the companies do that and don’t undercut each other.

[luplex]

Naively yes, it will be reduced, because these sails are not free.

[cess11]

They probably need to be tiltable to allow passage under bridges, as well as stable in pretty harsh conditions, such as storms, saltwater mist and ice buildup. Probably don't want to rely on it until you are very, very sure there is a stable supply of replacements for wearing parts.

[k99x55]

Lets hope Jevons paradox does not take effect: https://en.wikipedia.org/wiki/Jevons_paradox

[leptons]

That's great and all but the lowering of sulfur emissions from ships has recently been blamed for the consistent high temperature records across the globe due to less sun being blocked by those emissions. Be careful what you wish for?

>"Sulphur particles contained in ships’ exhaust fumes have been counteracting some of the warming coming from greenhouse gases. But lowering the sulphur content of marine fuel has weakened the masking effect, effectively giving a boost to warming."

https://www.carbonbrief.org/analysis-how-low-sulphur-shippin...

[itishappy]

Let's put that in context: we cut back on sulfur emissions because acid rain is terrible.

https://www.adirondackcouncil.org/page/acid-rain-86.html

https://www3.epa.gov/airmarkets/progress/reports/acid_deposi...

I don't believe anybody has suggested this policy was a mistake.

[leptons]

Sure acid rain is terrible, but warming oceans seem far worse. If the oceans warm enough, the methane trapped at the bottom releases, and goodbye habitable planet.

https://theconversation.com/frozen-methane-under-the-seabed-...