16 ms·

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

• joering2 8y ago
  What these ships are mostly surrounded by are waterfields that go as far as you can see. Can they come up with some sort of rolled flexible solar panels that once ship goes into full sail they release their “solar tail” behind that floats on the water surface and captures sun and turns it into electricity for ships’ engines? I mean 300 meters square of solar panel should be sufficient to push the ship at its nominal speed. For free!
  • village-idiot 8y ago
    I think the issue would be salt water. Salt water destroys everything, I can’t imagine that a PV array floating in water would have a good life expectancy. On the plus side, if the insulation fails you could turn container ships into accidental fishing boats.
    • cwmoore 8y ago
      > Salt water destroys everything This is the statement I hear relating to all kinds of ocean-based renewable energy ideas. Sources are never provided. The problem must have to do with economic viability and the replacement/maintenance costs exceeding savings. Could you supply sources to elaborate on where the break even point of solar tail (or any two other ocean renewable energy) systems would be as relates to costs and benefits? Edit: I don't really want to argue whether or not steel rusts in saltwater. My argument was that the break-even point of a "solar tail" is dismissed out of hand without sources because of land-based technologies being considered as the only ones.
      • jacquesm 8y ago
        > Sources are never provided. We also do not need to provide sources for statements such as 'water is wet'. Anything on a boat, or even shoreside near to the ocean is subject to corrosion and corrosion protection is a serious maintenance issue. I've lived 2 km from the sea and even there the nails would rust right out of the building due to the salt that the wind would carry in.
        • cwmoore 8y ago
          Yes, salt water is corrosive. And yet, there are metal ships with viable lifetimes. This sub-thread is a bit less helpful than I am asking for. Edit: Come on. It's not impossible to engineer for ocean use. Wave power generation: https://www.bbc.co.uk/news/uk-scotland-scotland-business-25084721 https://www.bbc.co.uk/news/uk-scotland-scotland-business-250... Longer term: https://en.wikipedia.org/wiki/Submarine_power_cable https://en.wikipedia.org/wiki/Submarine_power_cable
          • jacquesm 8y ago
            Salt water is so corrosive that there is a whole branch of materials science dedicated to coatings and all kinds of other anti-corrosion measures such as galvanic protection using sacrificial material. The evidence is overwhelmingly on the side of statements such as 'simple systems that work well on the shore need extensive rework for ocean deployment assuming they can work at all'. Even a simple scratch is enough to lay all your carefully produced work to waste.
            • cwmoore 8y ago
              Agreed that the environment is vastly different than on land, that a scratch through a coating is akin to no coating at all, that anti-corrosion measures are a constant vigil in oceans. But I asked for sources treating the proposal in the original comment, and got told that "water is wet".
          • village-idiot 8y ago
            It’s obviously not impossible, it’s just expensive, which is a problem in the given context.
            • cwmoore 8y ago
              How big is the check and why? That's what's so hard to get an answer for when people are determined already to not to try. I mean, I guess I have Google and a long-weekend. I was hoping for someone to drop an URL that can explain this and provide key terms.
      • telchar 8y ago
        Here's a source for you that mentions that even some typical formulations of stainless steel are susceptible to corrosion in saltwater: https://www.clintonaluminum.com/304-stainless-steel-in-seawater/ https://www.clintonaluminum.com/304-stainless-steel-in-seawa...
        • cwmoore 8y ago
          White bread is bad in saltwater too, that doesn't mean there aren't better materials for the application. https://www.quora.com/Does-aluminium-react-with-salt-water https://www.quora.com/Does-aluminium-react-with-salt-water https://en.wikipedia.org/wiki/Organic_solar_cell https://en.wikipedia.org/wiki/Organic_solar_cell
          • blueprint 8y ago
            Salt water destroys everything so don't build boats guys
          • telchar 8y ago
            That's the point of the source you requested and I provided: there are some formulations of stainless steel that are actually kind of ok in salt water despite most being poor. No one is arguing that it's impossible to build a bear with solar panels. The point is that you can't slap a cheap panel from Alibaba on a float and have any assurance that it will work reliably. Thus costs go up and the whole idea may become infeasible.
      • GlenTheMachine 8y ago
        I don't have a source, but as an engineer working for the US Navy, we are frequently told that the Navy spends an enormous amount of money on corrosion control. Like, in the billions to tens of billions of dollars per year. As a consequence, corrosion control is a significant fraction of the Navy's R&D budget. https://www.gao.gov/assets/650/647926.txt https://www.gao.gov/assets/650/647926.txt https://www.onr.navy.mil/en/Science-Technology/Departments/Code-33/All-Programs/333-sea-platforms-weapons/Corrosion-Control https://www.onr.navy.mil/en/Science-Technology/Departments/C...
        • cwmoore 8y ago
          Thank you.
      • chooseaname 8y ago
        How would you keep them clean enough to produce optimal output? Every drop of salt water would quickly dry and leave a salty residue. How do you clean that while at sea?
        • cwmoore 8y ago
          I am not the author of the original comment, but I really like the concept. From what I understood this would be floating at surface level and would be continuously washed over by surface water. There are many good objections. It may be that the original comment does not illustrate the promise of this energy platform very thoroughly.
  • jacquesm 8y ago
    For free, when there are no waves, when the sun is shining, when there is no other vessel that crashes in to them and when you convince someone to make it all and then gift it to you.
  • LeifCarrotson 8y ago
    300m^2 only gets you a couple hundred kW on the brightest days at peak efficiency. These ships require powerplants providing on the order of 50,000 kW. A 40-acre floating solar farm would add a LOT of drag. Better to make the solar farm stationary, use it to synthesize fuel, and run the ship with an internal combustion engine for power density. Maybe someday batteries could be used.
    • cwmoore 8y ago
      I believe you. The difference between required and available power is large. Can you provide sources that derive/explain/summarize the figures you present so that others may better understand the reasoning?
      • deleted 8y ago
        [deleted]
      • LeifCarrotson 8y ago
        Sure, sorry. The rule-of-thumb max for solar irradiance is 1 kW/m^2 (noon, clear day, low latitude, etc): https://en.wikipedia.org/wiki/Solar_irradiance#Irradiance_on_Earth's_surface https://en.wikipedia.org/wiki/Solar_irradiance#Irradiance_on... The rule-of-thumb for the electric power output of a solar cell is about 20% of the irradiance. https://en.wikipedia.org/wiki/Solar_cell_efficiency https://en.wikipedia.org/wiki/Solar_cell_efficiency And because this drops in the morning and evening and falls to zero at night, you realistically only get a bit more than 1kWh/day with a 1 m^2 solar cell. And these ships require huge powerplants. Maersk's biggest ships use this engine: https://en.wikipedia.org/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RTA96-C https://en.wikipedia.org/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RTA9... which outputs over 80 MW. No citation for the drag caused by a floating mat of solar cells. The fact that these enormous ships burn this much fuel should be evidence that dragging a much more enormous mat should show that dragging an even more enormous and more draggy mat would be a non-starter.
        • cwmoore 8y ago
          Thanks! My acceptance of the idea that drag might be manageable has to do with volume displacement and not surface area. A long shallow "tail" could exert orders of magnitude less drag (vis a vis surface area) than a deep heavy hull pushing up a big wake. (Related to why boats are long and narrow...) https://en.wikipedia.org/wiki/Wave-making_resistance https://en.wikipedia.org/wiki/Wave-making_resistance Edit: The fact that you see that as a clear non-starter has me wading into Google results for hydrodynamics. It is definitely over my head, but I am curious. Is there a rule of thumb for drag in water that I'm not finding? https://www.boatdesign.net/threads/wetted-surface-area-approximate-formulas.930/ https://www.boatdesign.net/threads/wetted-surface-area-appro... http://www.engr.mun.ca/~bveitch/courses/r-p/Assignments/ITTC-calculation-procedures-Lab1.pdf http://www.engr.mun.ca/~bveitch/courses/r-p/Assignments/ITTC... http://www.fade.up.pt/cifi2d/files/effect-of-wetted-surface-area-on-friction-pressure-wave-and-total-drag-of-a-kayak.pdf http://www.fade.up.pt/cifi2d/files/effect-of-wetted-surface-...
  • CodeCube 8y ago
    I'm guessing that you're underestimating the cost of drag ... tailing a 300 sq meter "boat" would probably require more energy than it could produce. I have no data, and haven't done any back of the napkin calculations to back up my stance ... but just look at the speed difference between a monohull vs a catamaran vs a foil sailboat. Reducing the contact area with the water (and thus reducing drag) is _everything_.
    • cwmoore 8y ago
      Drag increases with the square of velocity [1]. Some of the ships might be able to travel much slower? I keep asking for sources because dismissals out of appeal to obviousness are so ubiquitous. [1] https://www.lmnoeng.com/Force/DragForce.php https://www.lmnoeng.com/Force/DragForce.php Edit: Admittedly, you may be right, but without even back-of-the-envelope calculations, and with the assumption that these boats must go as fast as possible, I don't know why.
      • CodeCube 8y ago
        I too freely admit that you might be right as well (if the assumption of speed can be dismissed) ... lol, this feels like it would be perfect fodder for one of those physics youtube channels that answers channels, or perhaps XKCD's https://what-if.xkcd.com/ https://what-if.xkcd.com/
  • a_c_s 8y ago
    I think you're vastly overestimating the power output of solar cells. Using 20% efficiency panels gives us 0.2KW/m^2/hr. According to this Quora answer [1] a small container ship uses 15,000kW: for one 24 hour day that means it needs 360,000KWH in energy. If we assume 10 hours a day of full sunlight then we need 180,000m^2 (equivalent to 18 hectares or 44.48 acres or 33.7 football fields) of solar panels. This of course overly optimistic as it assumes no drag nor increase in power needed to haul these solar panels (and batteries for use overnight, etc.). [1] https://www.quora.com/How-much-does-it-cost-to-fuel-a-cargo-ship https://www.quora.com/How-much-does-it-cost-to-fuel-a-cargo-...
    • telchar 8y ago
      Nitpick, but 0.2KW/m^2/hr would be an acceleration, not a constant rate. You mean 0.2KW/m^2 - this is constant power output. W already includes a per-unit-time component. I'm nitpicky on this topic because of how many professionally-written articles I've seen make similar mistakes.
    • ant6n 8y ago
      I think you're under-estimating the power of the square. 180,000m^2 is 2 x 300m x 300m.
  • cwmoore 8y ago
    To entertain the strongest interpretation of the idea, for purposes of understanding the reasoning: consider a very large, very slow ship trailing a towed PV array not made of steel [1], additionally harnessing sea-surface energy, and the extension/retraction of the tow cable [2, 2.5], made from non-corrosive plastic or plastic-coated materials, that costs hypothetically nothing to maintain, but must be completely replaced every 10 years. What are the specifications of such a system that it would generate sufficient power to cost-effectively augment or replace internal combustion, and what would the viable price-point for installation be considering costs of bunker fuel? Other comments [3, 4, 5] added the kind of information that might help to answer that. I am interested in sources, and discussion which isn't immediately dismissive of something unproven. Put another way, how much would low-grade petro-fuels have to cost before this became a viable alternative, and what sources support your conclusions? [1] https://en.wikipedia.org/wiki/Organic_solar_cell https://en.wikipedia.org/wiki/Organic_solar_cell [2] https://en.wikipedia.org/wiki/Wave_power https://en.wikipedia.org/wiki/Wave_power [2.5] https://www.tugtechnologyandbusiness.com/news/view,hybrid-propulsion-chosen-for-smartug-design-concept_46834.htm https://www.tugtechnologyandbusiness.com/news/view,hybrid-pr... [3] https://news.ycombinator.com/reply?id=17886124 https://news.ycombinator.com/reply?id=17886124 [4] https://news.ycombinator.com/reply?id=17886177 https://news.ycombinator.com/reply?id=17886177 [5] https://news.ycombinator.com/reply?id=17886190 https://news.ycombinator.com/reply?id=17886190 Edit: spelling Edit 2: added a reference
  • harg 8y ago
    A typical 250W PV panel is 1.6m^2. 300m2 of these will give a peak power of about 47kW which is about 63hp. for comparison a Wärtsilä RTA96C is rated for over 80MW which means you'd need over 0.5million m^2 of PV panels to match this. (about 85 football pitches). Feasible but expensive
    • cwmoore 8y ago
      The idea that it would need to be 1000X bigger is helpful. The original poster's figure of 300m^2 does not make much sense.
      • cwmoore 8y ago
        Rereading with the principle of charity in mind, I think the original poster meant (300m)^2, though it was not clearly so.
• fmsf 8y ago
  It's called the Flettner rotor, it uses the Magnus Effect. Cool stuff but not exactly new tech. It gives a nice read, here's some links to wikipedia on the topic: https://en.wikipedia.org/wiki/Magnus_effect https://en.wikipedia.org/wiki/Magnus_effect and https://en.wikipedia.org/wiki/Rotor_ship https://en.wikipedia.org/wiki/Rotor_ship I'm curious of what will be the results.
  • curiousDog 8y ago
    Apparently this is a turbo sail and not the same as the Flettner rotor. The Wikipedia article you linked to mentions the same. Ones powered by electricity and one by air? Both seem to take advantage of the Magnus effect though
    • spydum 8y ago
      https://www.google.com/amp/s/amp.theguardian.com/environment/2017/mar/14/spinning-sail-reboot-cut-fuel-make-ocean-tankers-greener https://www.google.com/amp/s/amp.theguardian.com/environment... It’s not a turbosail. Turbo sails don’t rotate..
      • curiousDog 8y ago
        Ah, looks like you're right! I got confused by its mention in the article.
  • robfitz 8y ago
    They claim 7-10% reduction in fuel usage, with fuel making up 60% of their total costs. Given that they soon expect to be spending $5 billion/year on fuel for 800 ships, fuel spend is a bit north of $6 million/year for an "average" ship. But size seems to vary widely (they note that only the 80 of their largest ships are being considered for these sails). At an installation cost of $2 million, saving 10% of an "average" ship would return 600k per year, or a 3.5 year paypack, which seems well worth doing where possible. And they'll obviously get better than that on their 80 largest. Not a magic bullet by any means, but certainly seems worth using.
• deleted 8y ago
  [deleted]
• chodeboy 8y ago
  Not a single word about flettner in that article. Do they hate Germans or does it not fit the ____GROUNDBREAKING____NEVER_DONE_BEFORE____ narrative of today's newspaper articles?
  • baxtr 8y ago
    I don’t think WSJ “hates Germans”. Probably just poorly researched
    • deleted 8y ago
      [deleted]
  • Retric 8y ago
    "Shipping executives said previous efforts didn’t catch on with operators because either the costs of such technologies were too high or tests didn’t yield the expected fuel savings. But modern, lightweight and relatively cheap rotating sails show more promise, they said." That seems less revolutionary than evolutionary.
• IB885588 8y ago
  Another option is skysails (giant kites that drag the ship forward): https://en.wikipedia.org/wiki/SkySails https://en.wikipedia.org/wiki/SkySails Hopefully someday almost all ships have a mix of these things + maybe run on algae-based advanced biofuels or something like that.
  • village-idiot 8y ago
    Hydrogen fuel cells are looking likely. Solar will probably produce too much electricity for usage during the day, so use that spare energy to split water to create Hydrogen fuel.
    • delecti 8y ago
      I was curious how much sense this actually made so I did the math, sources at the bottom. I suspect my sources aren't perfect, but they're probably close enough to get an idea of things. Our hypothetical container ship is roughly 400m x 59m, or 23600 m^2, and solar panels generate ~4.5 kWh/m^2 after inefficiencies, giving a total energy generated of 106.2 megawatt hours per day for a ship, if you had a big solar array above all the containers. Assuming an 85% efficient hydrogen fuel cell, that gives you losses both in storing and reclaiming electricity from that storage process. Assuming 1/3 of your energy can be used while generating it and the other 2/3 has to be stored as Hydrogen and then spent to power the energy, losing energy both ways, that leaves you an effective ~81 MWh/day. Meanwhile the existing engines on that same container ship can currently run at about 90 MW, which means it can output more energy burning bunker fuel in one hour than our solar panels gave us in the entire day. Container ship size: https://en.wikipedia.org/wiki/Container_ship#Size_categories https://en.wikipedia.org/wiki/Container_ship#Size_categories Energy per day: https://www.quora.com/How-much-solar-energy-is-generated-per-square-metre https://www.quora.com/How-much-solar-energy-is-generated-per... Fuel cell efficiency: https://en.wikipedia.org/wiki/Fuel_cell https://en.wikipedia.org/wiki/Fuel_cell Container ship energy usage: https://newatlas.com/shipping-pollution/11526/ https://newatlas.com/shipping-pollution/11526/
      • village-idiot 8y ago
• singularity2001 8y ago
  wouldn't it help to add little shovels for friction?
• billconan 8y ago
  found this video explaining it https://www.youtube.com/watch?v=2OSrvzNW9FE https://www.youtube.com/watch?v=2OSrvzNW9FE
• abtinf 8y ago
  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 maintenance) trumps every other value. A pioneering containerized shipping company went bankrupt pursuing a high-speed shipping strategy that cost marginally more than low-speed competition. Edit: Oh, there is a second edition! Updated link. Edit: replaced unhelpful snark. https://www.amazon.com/gp/aw/d/0691170819/ https://www.amazon.com/gp/aw/d/0691170819/
  • jherdman 8y ago
    You might enjoy "Containers", an eight episode podcast about the shipping industry too. https://medium.com/containers https://medium.com/containers
    • heywire 8y ago
      Two non-technology related containers story on the front page of hacker news, and they're both actually really interesting! Happy Friday!
      • dmoy 8y ago
        Hey sails are technology. Just, really old technology. And these "sails" are much newer tech...
        • 8note 8y ago
          and containers themselves are pretty new technology
      • JshWright 8y ago
        Hmm... I've seen a couple shipping related stories, but nothing container related. This one is about tankers, and the other was about bulk carriers.
• ValleyOfTheMtns 8y ago
  I've been wondering why shipping companies haven't been doing this for years now. Whenever I brought it up with friends they would say it's probably not worth the effort, but I can't see how it wouldn't be worth it. It's essentially free energy to help move the ship around. Got to say, I feel vindicated by this story.
  • gardaani 8y ago
    The interest is rising. Here's the story about Viking Grace, a passenger vessel with the Flettner rotor: https://www.maritime-executive.com/article/viking-line-installs-rotor-sail-on-cruise-ferry#gs.wWbA3Ho https://www.maritime-executive.com/article/viking-line-insta... Here's a passenger's video about it. It spins quite fast: https://www.youtube.com/watch?v=Ir8YSRhMsXA https://www.youtube.com/watch?v=Ir8YSRhMsXA
  • IB885588 8y ago
    Inertia is hard to fight. Sometimes all it takes is one player in a market doing it and then everybody else follows/feels they have to also to compete. That's one reason why Tesla was such a catalyst for the whole industry and EVs. As long as nobody else was really making too much of an effort, everybody could just drag their feet.
  • Someguywhatever 8y ago
    Upfront cost of installation, and ongoing maintenance, and the fragility of sails at the time may have prevented them being used before now.
  • tomtimtall 8y ago
    Essentially free energy... except the cost to install, the cost to operate, maintainable and of cause the cost when one of them breaks and causes damage. For a lot of these “why don’t they just” the answer is simply that they did the math and saw too small an upside for too big a risk. They are trying this out to see if the overall concept works in practice or if it falls short.
    • ant6n 8y ago
• DannyB2 8y ago
  From TFA... > Maersk Line spent around $3.4 billion on fuel last year for its fleet of around 800 vessels. Wouldn't savings from wind power be bad for the petroleum industry? And therefore by lobbyist extension bad for everyone?
  • macmac 8y ago
    That's Maersk Line, which is the container shipping division of Maersk. The rotor sails are being installed on a tanker vessel from Maersk Tankers. Deck space is a valuable commodity on a container vessel, so not as obvious where to place the rotors.
    • DannyB2 8y ago
      I quoted that line exactly from TFA. (the friendly article)
      • macmac 8y ago
        I am sure you did. That doesn't make it any less misleading.
  • hinkley 8y ago
    Reducing operating costs often leads to higher overall demand.
  • kardos 8y ago
    Not at all, energy used transporting energy is wasted and works to reduce EROEI.
• factsaresacred 8y ago
  Copying the first comment from WSJ 'cause it's interesting: > These are known as Flettner rotors after the German engineer Anton Flettner who invented them and made the first rotor sailing ship in 1924, with one sailing one across the Atlantic in 1926 - and they are not turbo sails. They have generally been in disuse as it has been deemed that the energy expended in propulsion by Flettner rotors was higher than that for propellers - perhaps it seems with modern materials, wind monitoring and computer assisted controls this has been tilted to the favor of Flettner rotors. Flettner also invented trim tabs which any large power boat operator knows very well. > An interesting note, Flettner was considered so valuable to the Germans in WW2 that Heinrich Himmler, the head of the Gestapo saw to it that Flettner's Jewish wife was escorted to Sweden for her safety for the duration of the war.
  • eanzenberg 8y ago
    >> An interesting note, Flettner was considered so valuable to the Germans in WW2 that Heinrich Himmler, the head of the Gestapo saw to it that Flettner's Jewish wife was escorted to Sweden for her safety for the duration of the war. That's nice and all but he still helped the nazis with military research while many of his colleagues fled, Einstein included.
    • lostlogin 8y ago
      It’s hard to understand, as that’s more or less moving her so he doesn’t kill her.
      • deleted 8y ago
        [deleted]
      • eanzenberg 8y ago
        Great for his fam, bad for the other 8M jews (my grandparents’ families included)
        • robbiep 8y ago
• nabla9 8y ago
  Viking Line installed similar 80-foot rotor sail on a LNG powered Cruise Ferry on the route between Helsinki-Stockholm. It reduces power usage roughly 20 percent (900 tonnes CO2 annually). Compared to tankers ferries don't carry significant amount of weight even when they are full. They are basically full of air and 60-100 cars or trucks. Together with using LNG, periodically cleaning the bottom of the ship, slower speed and connecting to electric grid while in harbor the CO2 emissions are down significantly. The best way to reduce energy consumption for a ship is to reduce the speed and make thinner ships. This is the new trend in shipbuilding. New cargo ships optimized for slow speed don't have the bulbous bow because it does not increase efficiency in lower speeds.
  • jabl 8y ago
    > Viking Line installed similar 80-foot rotor sail on a LNG powered Cruise Ferry on the route between Helsinki-Stockholm. Turku - Stockholm, actually. > The best way to reduce energy consumption for a ship is to reduce the speed and make thinner ships. Do you mean thinner as in narrower, or thinner materials to save weight? If you mean narrower, I've understood bigger ships tend to have a length/width ratio of about 6:1, as a rule of thumb compromise between seakeeping ability, fuel consumption, cargo space etc. Do you have some more information about design tradeoffs going into such narrower ships? > New cargo ships optimized for slow speed don't have the bulbous bow because it does not increase efficiency in lower speeds. Oh, interesting! Any links for further reading on this topic?
    • nabla9 8y ago
      Ah yes. you are correct on both counts: Turku and narrower (I had brainfarts). reading: https://gcaptain.com/cma-cgms-22000-teu-ships-to-feature-bulbless-bow-made-for-slow-steaming/ https://gcaptain.com/cma-cgms-22000-teu-ships-to-feature-bul...
  • unwind 8y ago
    Just for completeness' sake, the ship is the MS Viking Grace[1]. It's fun seeing the LNG supply vessel AGA Seagas [2] in the early mornings, required since the city of Stockholm did not allow the refueling to happen by tanker truck for safety reasons. [1] https://en.wikipedia.org/wiki/MS_Viking_Grace https://en.wikipedia.org/wiki/MS_Viking_Grace [2] http://www.aga.ee/en/products_ren/liquefied_natural_gas/maritime_fuel/seagas/index.html http://www.aga.ee/en/products_ren/liquefied_natural_gas/mari...
• komali2 8y ago
  > Fuel makes up approximately 60% of our total cost and this technology has a significant potential to cut fuel consumption by 7% to 10% on the ships that it will be installed." Jesus, I'm surprised we haven't seen all sorts of crazy ideas coming out of Maersk to reduce this overhead given that it's the bulk of their cost. Wind pillar things seem kinda tame compared to the shit I'd try to pull to save that level of money... Across all vessels no less!!
• carapace 8y ago
  Magnus Effect. As sled runners are to wheels, so the wing is to the Magnus effect rotor. Lift goes up with the square of the radius. Think about that. I'm in the process of ramping up a toy company that builds and sells kits for Magnus Effect drones. I plan to just keep making them bigger, first for cargo then for mass transport. It will be necessary to move people efficiently by the million in the decades to come. Already floods and wildfire have begun to increase, soon enough the waters will rise and it will be needful to move our asses. By using a simple recursive-fractal infrastructure there's pretty much no upper limit. Cf. "Tensarity"[1] and Alexander G. Bell's cellular kites[2]. Also Bucky Fuller's Cloud Nine[3]. Self-powered[4][5]. I imagine huge aerial machines, more like gauzy flying buildings than aircraft, that carry a million or more people at a time. Cities in the sky. [1] https://en.wikipedia.org/wiki/Tensairity https://en.wikipedia.org/wiki/Tensairity [2] https://duckduckgo.com/?q=Alexander+G.+Bell%27s+cellular+kites&t=hj&atb=v110-1_b&iax=images&ia=images https://duckduckgo.com/?q=Alexander+G.+Bell%27s+cellular+kit... [3] https://en.wikipedia.org/wiki/Cloud_Nine_%28tensegrity_sphere%29 https://en.wikipedia.org/wiki/Cloud_Nine_%28tensegrity_spher... [4] Tethered power generators, "Magenn" company, defunct? https://en.wikipedia.org/wiki/Airborne_wind_turbine https://en.wikipedia.org/wiki/Airborne_wind_turbine [5] https://en.wikipedia.org/wiki/Vaneless_ion_wind_generator https://en.wikipedia.org/wiki/Vaneless_ion_wind_generator
• ourmandave 8y ago
  In a different related article I learned that Ro-Ro vessels are Roll-on Roll-off cargo vs Lo-Lo vessels which are Lift on - Lift off. And I thought IT loved acronyms.
• mvpu 8y ago
  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...
  • ethagknight 8y ago
    Two problems with boats and solar propulsion: 1) they need 24/7 power. 2) Using a random LG 330 W panel on top of the Edith Maersk, it would take an array 1/3 of a mile by 1/2 of a mile in area to match Edith's 80,000 kW engine power output. Edith is 1/4 mile long and 3/100ths of a mile wide. Quite a gap, and thats before you start factoring in batteries for the night, structure to support the array, storms...
    • Faaak 8y ago
      Though you could power the ship from solar during the night and with diesel generators during the night.
    • Steko 8y ago
      > 2) Using a random LG 330 W panel on top of the Edith Maersk, it would take an array 1/3 of a mile by 1/2 of a mile in area to match Edith's 80,000 kW engine power output. Edith is 1/4 mile long and 3/100ths of a mile wide. Back of the envelope math says we're short by a factor of ~108. We can get savings in a few places: (1) We don't have to match the full engine output with solar. Many container ships use super slow shipping at a fraction of the power, [1] says 10% engine load. With batteries you can still increase throughput substantially when needed. (2) Panels can exceed current ship dimensions, perhaps greatly (tow a long tail of solar panels on floats?). Let's just go for double width and length for now. (3) Efficiency gains. We're at 20% in back of envelope above but I can get that for my house. Let's say Maersk ponies up for 30% cells. Still some ground to make up but at least we're in bullshitting distance of claiming it's viable. [1] http://articles.maritimepropulsion.com/article/Turbocharger-Retrofit-Aids-Slow-Steaming41703.aspx http://articles.maritimepropulsion.com/article/Turbocharger-... > thats before you start factoring in batteries for the night, structure to support the array Presumably there's some space/weight savings in not having an 80MW engine.
• adam 8y ago
  This should be a big deal for combatting CO2 emissions as well. I believe it was never refuted after it came out a few years ago that ~15 of these ships emit the same CO2 as all cars in the world? https://inews.co.uk/news/long-reads/cargo-container-shipping-carbon-pollution/ https://inews.co.uk/news/long-reads/cargo-container-shipping...
  • slapshot 8y ago
    The article says "pollution" not CO2. Given that they burn bunker fuel (very dirty oil left over after things like gasoline are refined away), it's likely the article means particulate or sulfur emissions. The CO2 emissions are easily estimated and not even close. A container ship can burn 225 tons of bunker fuel per day at normal cruising speed.[1] At a generous 300 days in transit per year (they spend time in port loading / unloading / waiting), that's 67,500 tons of fuel per year. It's a massive number, but a drop in the bucket relative to the 913 million tons of oil consumed by Americans every year, the majority of which is spent on motor vehicle fuels.[2] Even assigning just 50% of US oil consumption to cars, you're comparing about 450 million tons consumed by American drivers versus about 1 million tons for 15 large cargo ships. [1] https://transportgeography.org/?page_id=5955 https://transportgeography.org/?page_id=5955 [2] https://www.statista.com/statistics/264825/oil-consumption-in-the-united-states/ https://www.statista.com/statistics/264825/oil-consumption-i...
• tunnuz 8y ago
  https://en.wikipedia.org/wiki/Magnus_effect https://en.wikipedia.org/wiki/Magnus_effect
• lgats 8y ago
  https://www.fullwsj.com/articles/maersk-tankers-turns-to-wind-power-to-cut-soaring-fuel-costs-1535641239 https://www.fullwsj.com/articles/maersk-tankers-turns-to-win...
• chooseaname 8y ago
  Was hoping to see more than 10% reduction. Seems fuel prices could easily absorb that quickly.
• qume 8y ago
  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-shipping-lanes_957b.png https://earthjustice.org/sites/default/files/world-cargo-shi... [2] https://earth.nullschool.net/#current/wind/surface/level/orthographic=-157.21,10.45,671/loc=-131.119,24.791 https://earth.nullschool.net/#current/wind/surface/level/ort...
  • craftyguy 8y ago
    These use rotor sails, which are different than what you have on your boat. Unless of course you also have rotor sails?
• JamesCoyne 8y ago
  This led me to wonder how important height was a restriction on ships. Turns out "air draft" is reported for major ports. Some interesting findings: The Panama Canal has an air draft of 201 ft imposed by the Bridge of the Americas; the Port of Oakland has an air draft of 220 ft imposed by the Golden Gate Bridge. Height from waterline does not appear to be typically listed for ships, but I would guess that most cargo vessels do not have 100 ft of clearance to spare. I think this means these sails would only be fitted to vessels which generally don't care about height restrictions (e.g. ships larger than Panamax) or ships running predictable routes. https://en.wikipedia.org/wiki/Air_draft https://en.wikipedia.org/wiki/Air_draft
  • nattaylor 8y ago
    I believe the unloaded freeboard of a typical containership is 80-100' The bridge (navigation deck) is higher, but the "sails" would be mounted from the deck, so I expect most ships would be OK.
    • JamesCoyne 8y ago
      Right, but container ships are stacked with containers higher than the top deck. So maybe this only makes sense for tankers and bulk carriers, or any large cargo vessel that is not a container ship.
• Jsharm 8y ago
  A little embarrassed to ask but why would normal sails not work?
  • wingerlang 8y ago
    I don't know, but this looks very space saving and have much less moving parts.
  • interdocken 8y ago
    maintenance. the materials used for actual sails stretches eventually and is less effective. presumably these towers have very little to replace.
    • jhayward 8y ago
      They have a very expensive, hard to replace, and high maintenance bearing at the base of the tower that carries the full force of the sail leveraged by a long moment arm. This bearing (along with lack of height = low wind) has been the reason that Flettner sails and wind turbines haven't been economical in the past.
  • jabl 8y ago
    I guess too labor intensive, and probably problems scaling up to the size of current ships. Consider the last generation of sailing cargo ships before steam took over (https://en.wikipedia.org/wiki/Windjammer https://en.wikipedia.org/wiki/Windjammer ), those were around 2000-5000 GRT, compared to a big container ship today at something like 170000 GRT. The tonnage difference is rather massive. Also, if you look at pictures of windjammers, masts, rigging etc., would get in the way of cargo handling. Less so on a tanker compared to, say, a container ship, of course.
• lucidguppy 8y ago
  Think of the PR we could harness with this alternative energy source!!!
• Timmah 8y ago
  Would be excited to see this technology combined with the "underbelly bubbles" technology that I heard about a few years ago where they reduce drag by releasing air bubbles under the hull. Yeah it takes energy to do it but the decreased resistance is supposedly a net gain. Two 10% gains would be awesome.
  • nattaylor 8y ago
    Some fleets have implemented special bottom paint to reduce drag by reducing algae growth.
    • adrianN 8y ago
      I wonder how long a magnetic cleaning robot could survive on the hull of such a ship.
      • superkuh 8y ago
        After manned narco subs and towed sub capsules were mitigated by new police efforts drug traffickers experimented with magnetically attached parasite containers on the side of large shipping boats. But they didn't have to move.
        • Timmah 8y ago
          How do they mitigate narco subs? Sonar patrols I presume?
• poorman 8y ago
  I hear this is what Nautilus Labs is trying to solve https://nautiluslabs.co https://nautiluslabs.co
• newnewpdro 8y ago
  Calling these sails is a stretch, and IMHO just an attempt to market them as more "green" than they really are. They may as well be propellers. It's great to improve the fuel efficiency of these vessels, but the word sail evokes a mental image profitably inconsistent with reality.
• korbonits 8y ago
  SAILING FOR THE WIN
• krupan 8y ago
  How loud are these when they are rotating?
• paulsutter 8y ago
  Noting the use of the plural, How many are installed on the ship? We see two(?) in the photo? What’s the practical limit? > has installed 100-foot-tall rotating cylinders on one of its product tankers
• joeborza 8y ago
  Amazing, new, disruptive technology for shipping... Now who has the patent on SAILS! This kind of reminds me of constant remakes of Spiderman ;0)