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I recently read The Ministry for the Future by Kim Stanley Robinson, and one of the ideas in it that I thought was very good was replacing our cargo ships with
by chris12321 1y ago
I recently read The Ministry for the Future by Kim Stanley Robinson, and one of the ideas in it that I thought was very good was replacing our cargo ships with wind-powered ships, basically giant sailing ships. In the book, they were incredibly slow, with shipments taking months to complete, but if supply lines were set up correctly, that wouldn't matter for a lot of cargo. Cargo ships are a massive CO2 contributor, and it was interesting that a solution could be to return to sailing ships.
I know there are probably huge engineering problems preventing this from happening, so feel free to tell me why it's impossible.
- hyperhello 1y agoThere's nothing stopping it, here's a link to an article from 2023: https://www.bbc.com/news/technology-66543643 https://www.bbc.com/news/technology-66543643
- xterminator 1y agoWhy can't cargo ships deploy floating solar panels to power the ship motors?
- dragonwriter 1y agoBecause floating solar panels add drag proportional to their area, and it takes a lot of area of panels to power a motor that is sufficient for a cargo ship even without the added drag of the panels. Also, because oceans and the things one runs into in them aren't easy on solar panels being dragged along by cargo ships.
- PicassoCTs 1y agoWould make more sense to produce chemical from solar energy harvested on the water fuels, collect the fuel and then use this with ships
- retrocryptid 1y agoi wish there was more talk about this. it seems i heard a lot about making hydrocarbons from co2 in the air + solar or algae a couple years ago. if your hydrocarbons are made this way it seems they would be carbon neutral. i'm guessing there's more research to make it feasable since i haven't seen "carbon neutral gas alternative" at the local Chevron.
- crote 1y agoThere has been quite some buzz about ammonia, as it is fairly easy to turn electricity into hydrogen, and hydrogen into ammonia. It has a reasonably high energy density, is not too nasty to handle, and already has a huge industry built around it.
- jauntywundrkind 1y agoMy understanding is that drag is more about the "front-on" view of a craft than how long the craft is. Since solar panels are very thin and aimed up, it feels like they add minimal cross-sectional area to the craft. Your assertion seems trivially incorrect to me?
- numpad0 1y agoShips drag across sticky goop, not fly through soup.
- aliher1911 1y agoThere's a pressure drag and skin friction drag. Friction drag is supposedly a majority component unless you sail a brick. But I don't have sources to prove that.
- ben_w 1y agoOceans can be extremely rough, but even mild waves make it inappropriate to approximate PV as thin. The requisite area to power a ship is huge, something like 1.4km^2 (ballpark estimate for 20% cells, reasonable capacity factor guess, 60 MW consumption requirement). If a ship is about 30m wide, it's trailing about 45 km of PV. You're not even into 4 digits of cargo ships before the combined length is longer than the circumference of the planet.
- dragonwriter 1y ago> My understanding is that drag is more about the "front-on" view of a craft than how long the craft is. Drag (fluid mechanics generally) is... ludicrously complicated. For the typical shapes of ships, I believe you are correct that the main factor is cross sectional area perpendicular to the direction of travel, but that’s not universally true. i think that for a floating raft of panels, it would be proportional to the panel area, similar to how for winged aicraft its the wing area and not the cross section perpendicular to direction of travel.
- buckle8017 1y agoEconomics. The solar panels would be more expensive than bunker fuel. Sails would be cheaper.
- retrocryptid 1y agoit might be fun to try to make a modern wooden sailing ship cargo fleet. maybe with an emergency diesel engine in the back.
- seb1204 1y agoIt's been done, however the scale of modern Panamax containerships is baffling and most people underestimate their size. https://www.newscientist.com/article/2445620-worlds-largest-sailing-cargo-ship-makes-first-transatlantic-voyage/ https://www.newscientist.com/article/2445620-worlds-largest-...
- xnx 1y agoInteresting idea, but that would require more than a square kilometer (or a 100m strip 10km long) of solar panels (not accounting for the additional power required to tow the panel array).
- Retric 1y agoSolar power being useful doesn’t require 100% of propulsion to come from solar panels. You see solar panels added to a wide range of boats because even bunker fuel isn’t free and panels are light for the power they provide over even a few days. A current 399.9 * 61.3m container ship doesn’t need panels everywhere to benefit, but the potential savings is significant if they do.
- svnt 1y agoThis is unfortunately not true because of the dynamics of diesel engines: there is by design surplus energy relative to requirements from running them at efficient operating points. Otherwise the ship is not a good ship.
- Retric 1y agoYou can always scale design to fit reduced demand. Also, loss of efficiency is more than made up for with vastly lower energy demand. “Lowering speed reduces fuel consumption because the force of drag imparted by a fluid increases quadratically with increase in speed. Thus traveling twice as fast requires four times as much energy and therefore fuel for a given distance.” https://en.wikipedia.org/wiki/Slow_steaming https://en.wikipedia.org/wiki/Slow_steaming “Container ship Emma Mærsk in Aarhus, 5 September 2006 Mærsk Line's E-class container ships such as the Emma Mærsk can save 4 metric kilotons of fuel oil on a Europe-Singapore voyage by slow steaming.[5] At typical fuel prices of US$600-700 per tonne,[4] this works out to a saving of US$2.4-2.8 million on a typical one-way voyage. Maersk's Triple E-class container ships were designed for slow steaming and have less powerful engines than their predecessors.[5]”
- svnt 1y ago
- delusional 1y agoI'm not an expert, but I've worked close to some of the engines that power those ships. My gut feeling is that you're vastly underestimating how much power those ships consume (and therefore produce).
- aerostable_slug 1y agoCurrently, ships need human sailors. They perform maintenance aboard ship as well as have legal oversight of the craft. We are not yet able to replace the crew with automation. It's difficult to find skilled crewmembers willing to sign up to extremely long rotations away from home.
- hansvm 1y agoIt just takes money. $100k-$300k/yr is plenty to have your pick of pretty good people, especially if there are any perks like the food being halfway decent (should be basically a given if you have to pay the chef a lot anyway).
- B1FF_PSUVM 1y agoWith a fraction of the money, you pay for energy to move faster ...
- lelandbatey 1y agoThat's not even close to true for the kind of large shipping we're talking about. Crews are small (the Ever Given had 25 people on board) but the ships they crew take up to ~100k gallons of fuel per day (Ever Given has a fuel capacity of 3622168.679 gallons, 13711400 liters, and is set up for voyages of ~30 days underway). Fuel costs are ~$2.5 USD/gallon for bunker fuel. That means a cool $200k per day (conservatively). It is absolutely not the personnel costs that'd be the big differences in expenses.
- B1FF_PSUVM 1y agoGood point, I didn't have a handle on the fuel costs. Backup argument: if you go at half-speed, you'll need twice as many ships for the same throughput.
- hansvm 1y agoNot really. The unit economics work out heavily in favor of wind even with slower trips and absurd wages and the fact that oil has its externalities pushed to other people. Ignoring local manufacturing minima, the reason we don't do more of it is that the capital outlay is important and heavily favors faster trips, much like how excess solar for refinery power isn't often enticing because the factory spends too much time idle. Combine that with manuverability in canals (so you probably need a powerful engine anyway), and the project needs a lot of TLC to make economic sense while oil is subsidized to this degree, but unit costs aren't the culprit, and even wages at that extreme are totally fine.
- pragma_x 1y ago> if supply lines were set up correctly, that wouldn't matter for a lot of cargo. One of the big problems facing logistics across the board is just optimization. But at some point, you run out of intuition to uncover more efficiencies. This space is actually a really good use for AI. In fact, it's even useful for predicting what to put on that boat ahead of when it's ordered/purchased (up to a point). So yes, longer shipping times might not be that big a deal for non-perishables and frozen products.
- DickingAround 1y agoWe should not under-estimate the need for speed in supply chains. Predicting future demand is hard. To be more specific, we're talking about predicting ~100M unique products (the order of magnitude that moves on the pacific) and some of them have very lumpy demand (e.g. invent a new product, but it depends on 100 other obscure products).
- ted_dunning 1y agoWe should also not over-estimate the need for speed. Just because some items need speed, it does not follow that all items need speed.
- sightbroke 1y agoOr Nuclear Propulsion: https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#Merchant_ships https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#Merc... > Nuclear ships are currently the responsibility of their own countries, but none are involved in international trade. As a result of this work in 2014 two papers on commercial nuclear marine propulsion were published by Lloyd's Register and the other members of this consortium.... > This is a small fast-neutron reactor using lead–bismuth eutectic cooling and able to operate for ten full-power years before refueling, and in service last for a 25-year operational life of the vessel. They conclude that the concept is feasible, but further maturity of nuclear technology and the development and harmonisation of the regulatory framework would be necessary before the concept would be viable. > In December 2023, the Jiangnan Shipyard under the China State Shipbuilding Corporation officially released a design of a 24000 TEU-class container ship — known as the KUN-24AP — at Marintec China 2023, a premier maritime industry exhibition held in Shanghai. The container ship is reported to be powered by a thorium-based molten salt reactor, making it a first thorium-powered container ship and, if completed, the largest nuclear-powered container ship in the world.
- crote 1y agoNuclear ships are technically possible, but have a massive number of downsides. - The construction cost would be significantly higher than a conventional ship. - Reactors are far from trivial, so you'd double or triple the crew required. - Shipbreaking would become even more of an issue than it already is. You can't just beach a ship like this in Bangladesh and have a bunch of untrained people attack it with plasma cutters. - The ship would be a huge target for pirates and terrorists. It's essentially a floating dirty bomb, after all, just waiting for the USS Cole treatment. - A lot of countries would not accept nuclear ships, both due to perceived security risks and for more ideological reasons. ... and that's probably only the tip of the iceberg. Nuclear is barely economically viable with land-based large-scale nuclear power plants running for 50+ years. They are an attractive option for some military ships, but I doubt anyone would be willing to risk it for regular commercial shipping.
- sightbroke 1y ago
- kjkjadksj 1y agoWe probably don’t have the physical space to onshore 6x the capacity in warehouse or whatever it would work out to around ports. Short of multilevel warehouses but I mean containers have been stacked 5 high since covid around the port of LA and I think that is about the limit without some significant rethinking of process. Maybe the ships could just anchor off shore for longer and function as the warehouse.
- hedora 1y ago> Cargo ships are a massive CO2 contributor Not really. They’re 1.6% of global emissions if I multiplied the numbers on this page out right. The table says they’re 20% of shipping emissions, and the intro says shipping is 8% of global emissions (excluding ports and warehouses). This result seems surprising until you realize that semi trucks produce 100x more CO2 per kg-mile of cargo. https://climate.mit.edu/explainers/freight-transportation https://climate.mit.edu/explainers/freight-transportation