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Maersk installed 100-foot-tall rotating sails on one of its tankers

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Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#111
post #103

Earlier quoted context omitted.

Ignorant question: if operational costs trump all, especially fuel (Maersk says in the article 60% of operational cost) why not pure sail power? Is there some other maintenance cost or infeasability there? Or is there another hidden variable that is not satisfied?

I've long imagined some fun possibilities for this. I picture a small-ish shipping ship, say something moving 20 or 30 containers only, fully autonomous (100% crewless) with sails and solar only powering it. Solar electric motors handling the near-land operations and "not enough wind" conditions, sails otherwise. If you had autonomous loading and unloading, you would have zero variable/operational cost. I am certain…

No hostages for pirates to take either (though I guess they could help themselves to all of the goods on the ship)

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#112
post #105

Earlier quoted context omitted.

Ignorant question: if operational costs trump all, especially fuel (Maersk says in the article 60% of operational cost) why not pure sail power? Is there some other maintenance cost or infeasability there? Or is there another hidden variable that is not satisfied?

Slow is OK, but it must be exactly predictable. Don't be early, don't be late. So you can use sails to help, but if you rely on them you might be late.

You can keep the timetable no matter what -- use sails just to save fuel consumption when weather is favorable.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#114
post #103

Earlier quoted context omitted.

Ignorant question: if operational costs trump all, especially fuel (Maersk says in the article 60% of operational cost) why not pure sail power? Is there some other maintenance cost or infeasability there? Or is there another hidden variable that is not satisfied?

I've long imagined some fun possibilities for this. I picture a small-ish shipping ship, say something moving 20 or 30 containers only, fully autonomous (100% crewless) with sails and solar only powering it. Solar electric motors handling the near-land operations and "not enough wind" conditions, sails otherwise. If you had autonomous loading and unloading, you would have zero variable/operational cost. I am certain…

Another fun possibility: a train of such ships connected by cables, which wind and unwind generators as the distances between them change, to power propulsion.

As for very good reasons why this would never work, sometimes that is beside the point. I am not in the running to redesign trade and power on my own terms, but sometimes I can flush out assumptions that don't need to be held.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#115

Earlier quoted context omitted.

Clarification: I was talking about using excess electricity from shore based solar units. This would give operators somewhere to dump excess power cheaply (preventing negative electricity rates), all while providing fuel that's easy to store and usable in applications where batteries wouldn't work. Obviously at this point fuel cells cannot produce the power output that diesel engines can at a given weight. But your p…

> But your power estimates on what a hydrogen fuel cell can do are off by a bit My estimate didn't assume the ship left the shore with any hydrogen fuel. I (apparently incorrectly) assumed you meant that the ship would generate its own hydrogen during the day from excess solar while it was in transport.

Ah yes, that wouldn't work at all.

If solar cells got effective enough to generate that much power, you’d probably be better off with solar + battery anyhow.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#117
post #18

Some years ago I read The Box by Marc Levinson, a history of containerized shipping. Highly recommend it. If you live in SF and have wondered about the numerous barely used piers, this book explains their history as well - and why the major container terminal ended up in Oakland instead. One of the painful early lessons for the industry was the discovery that minimizing operational costs (particularly fuel and mainte…

Ignorant question: if operational costs trump all, especially fuel (Maersk says in the article 60% of operational cost) why not pure sail power? Is there some other maintenance cost or infeasability there? Or is there another hidden variable that is not satisfied?

I wonder: do sails alone generate enough power to move today's massive container ships? Or would the ships need to be smaller?

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#118
post #18

Some years ago I read The Box by Marc Levinson, a history of containerized shipping. Highly recommend it. If you live in SF and have wondered about the numerous barely used piers, this book explains their history as well - and why the major container terminal ended up in Oakland instead. One of the painful early lessons for the industry was the discovery that minimizing operational costs (particularly fuel and mainte…

Second the recommendation. Great book!

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#119
post #91

Wonder why ships aren't trying solar panels and electric motors and auto-pilot... they're out in clear Sun, have a large surface area, and no traffic...

How would you keep the salt off of them in order to keep them producing optimal power?

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#120
My small 12 meter long boat has a sail area of 900sqft. When sailing perpendicular to the wind it captures pretty much all of that.

The sail on that ship is 100' high, and looking at the aspect is around 15' wide, or 1500sqft. That type of sail I think only harneses half of that area, so half of 1500' or 750' best case.

I can say with complete confidence that if all the energy from two of my boats were towing one of those ships, even in a hurricane, it's going to increase fuel efficiency by approximately 0.0%

EDIT: I just did a random sample of wind speed [1] of points on the globe on international shipping routes [2] and it looks like they are generally around 10-15km/h. Thats barely enough to get my boat up to speed. There is a reason sailboats take very particular routes and don't just go from point A to B

[1] https://earthjustice.org/sites/default/files/world-cargo-shi...

[2] https://earth.nullschool.net/#current/wind/surface/level/ort...

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