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Isn't it feasible for container ships to go electric ? They have such massive surface areas for batteries. I thought of solar but then the container loading/unl

by deepGem 10y ago

Isn't it feasible for container ships to go electric ? They have such massive surface areas for batteries. I thought of solar but then the container loading/unloading aspects will become quite cumbersome, unless you could somehow put solar panels on individual container roofs and load those on the top. A logistical nightmare nonetheless. A crude search yields this about Emma Maersk, one of the largest container ships. She is powered by a Wärtsilä-Sulzer 14RTFLEX96-C engine, the world's largest single diesel unit, weighing 2,300 tonnes and capable of 81 MW (109,000 hp) when burning 14,000 litres (3,600 US gal)[31] of heavy fuel oil per hour. At economical speed, fuel consumption is 0.260 bs/hp·hour (1,660 gal/hour).[32] She has features to lower environmental damage, including exhaust heat recovery and cogeneration.[33] Some of the exhaust gases are returned to the engine to improve economy and lower emissions,[34] and some are passed through a steam generator which then powers a Peter Brotherhood steam turbine and electrical generators. This creates an electrical output of 8.5 MW,[35] equivalent to about 12% of the main engine power output. Some of this steam is used directly as shipboard heat.[36] Five diesel generators together produce 20.8 MW,[35] giving a total electric output of 29 MW.[26] Two 9 MW electric motors augment the power on the main propeller shaft So you need about 285 Tesla Models P100D motors to power a ship of this size. Doable I guess. Again, I'm no expert on shipping.

ForHackernews 10y ago
One of the more interesting retro-futuristic ideas is to use wind power and large, high-altitude kites to help propel big oceangoing cargo ships: http://newatlas.com/cargill-ship-will-be-largest-ever-to-utilize-kite-power/18005/ http://newatlas.com/cargill-ship-will-be-largest-ever-to-uti...
Retric 10y ago
These ships are a very poor place for battery's vs cars because of how infrequently they recharge and how efficient their engines are. They extract ~2.5x as much energy from their fuel so the real solution is changing fuels and adding a catalytic converter not battery's. PS: Remember, this pollution has a short half life, so it's simply not around that long.
dredmorbius 10y ago
No. The combined power and capacity constraints make solar a nonstarter. Specialised, high-efficience, very light, all-electric boats have been built. They top out at about six knots, roughly 1/4 the speed of most shipping of the 1980s and 1990s (more recent ships have slowed somewhat to about 18-20 kt for efficiency, called slow steaming). We had a technology for low-fuel shipping, it's called sails, and achieved net speeds of 12-20 kt with cargoes. Commercial sail vessels actually operated through the 1940s, in rare cases, as fuel costs and limitations were still concerns. These ships could and did out-pace coal-fired boats. They are, however, dwarfed by modern monsters such as the Emma. https://en.m.wikipedia.org/wiki/Gustaf_Erikson https://en.m.wikipedia.org/wiki/Gustaf_Erikson https://en.m.wikipedia.org/wiki/Windjammer https://en.m.wikipedia.org/wiki/Windjammer
- deleted 10y ago
  [deleted]
- usrusr 10y ago
  Thank you for the Wikipedia ride, now I'm kind of waiting for Larry Ellison to enter grain shipping with ocean skimming carbon composite monstrosities ;) (Or at least for a Neil Stephenson novel about that happening)
  - dredmorbius 10y ago
    Carbon-composite monstrosities? So ... Clipper Ships? ;-)
jdblair 10y ago
You're using power (MWh) to make your point, but the crucial practical issue is energy storage (MWh). According to this chart[1], bunker fuel has about 80 times the energy density of lithium batteries. Something has to charge those batteries, too, so there will be another fuel source required generate the electricity. Container ships do have large surface area, and its conceivable - it might be practical to build a hybrid solar/diesel ship. I can imagine most of the system being packaged in containers with solar cells on the top, and batteries and inverters inside. They would then be loaded last, on top of of the load and connected to a ship-board motors. 1: https://people.hofstra.edu/geotrans/eng/ch8en/conc8en/energycontent.html https://people.hofstra.edu/geotrans/eng/ch8en/conc8en/energy...
- Pxtl 10y ago
  The challenge is that container ships don't have a roof over the containers. You'd have to have shipping container sized solar banks placed on top of each container, then wire them into the ship's power system. Every load and unload would add extra time spent unhooking, unloading, reloading, and reconnecting the solar roofs.
  - D-Coder 10y ago
    4U solar banks (each one fits over four, or some multiple, of containers). Cuts the annoyance down a bit.
  - ams6110 10y ago
    Container ships also sail at night.
    - jdblair 10y ago
      Its why this would purely speculative exercise would be hybrid - it would still need a diesel engine, it would just burn less fuel. Regardless, I expect the cost of running a ship's engine on bunker fuel is so low there's little incentive for this.
- jdblair 10y ago
planteen 10y ago
The issue is energy density, not motors. The ship burns 1,660 gal/hr = 6000 L/hr when at "economical speed". The energy density of fuel oil is about 10 kWhr/L. Googling tells me that a journey between China and California by ship takes 2-4 weeks. So for three weeks of economical speed, that is 30 MWhr of energy. That is the size of the largest battery installation in North America, the Tehachapi Energy Storage Project. The batteries will weigh about 25 times more than the diesel fuel would weight (assuming fuel oil at 13,000 Wh/kg and 500 Wh/kg for batteries).
- knodi123 10y ago
  That calculation is for a purely battery powered vessel. I think the person you replied to was suggesting much lower battery capacity, and running primarily while the sun shines, using non-stored electricity. Still isn't enough, but it's a different calculation.
  - Dylan16807 10y ago
    Let's do that calculation. It looks like if you covered the entire surface area of the ship in 100% efficient solar panels then at high noon near the equator you would get just about enough power to run at "economical speed". Put on realistic cells and account for the motion of the sun and you won't have 1/10th the power you want.
    - knodi123 10y ago
      Wow, I wouldn't have thought it could even get that close. But as long as we're spitballing.... If you're running on solar and you are only carrying enough batteries to last through the night, then your ship isn't carrying all that fuel, and the enormous engines to burn it (and, heck, alternators). So the boat will have a lot less mass, and a lot less draft - so you can significantly lower the power requirements. Add a SkySail, and relax your shipping deadlines, and maybe you could make it work? * https://en.wikipedia.org/wiki/SkySails https://en.wikipedia.org/wiki/SkySails
      - 10y ago
bluedino 10y ago
1 Westinghouse nuclear powerplant like used in an aircraft carrier will make 100MW.
- macmac 10y ago
  There have been nuclear merchant vessels in the past and there are still nuclear ice-breakers around. The nuclear merchant vessels were never a success, due to various challenges, some of the outlined in this article: https://www.flexport.com/blog/nuclear-powered-cargo-ships/ https://www.flexport.com/blog/nuclear-powered-cargo-ships/
  - dmoy 10y ago
    Huh the last bit of that article seems very pro nuclear container ship primarily due to oil price instability and environmental concerns. Interesting read though, I wonder if the US's nuclear ship was a decade later and actuallytrying to be commercially viable if we'd have nuclear container ships right now.
- hectorr 10y ago
  I love nuclear power, but there is a huge gap between how the Navy runs their nuke fleet and how the civilian maritime world operates. Navy nukes are some of the most insanely anal and uptight professionals you will ever meet. It's a zero-defect culture, because it has to be. The job of civil maritime is to provide commodity supply - the only way to make money over the long term is to be a low cost operator. The best (usually Greek) shipowners will milk every last dollar out of an asset, which down in the bilges means fixing boilers with duct tape and bailing wire. That's not how you want to run a nuclear plant.

by deepGem 10y ago

ForHackernews 10y ago

One of the more interesting retro-futuristic ideas is to use wind power and large, high-altitude kites to help propel big oceangoing cargo ships: http://newatlas.com/cargill-ship-will-be-largest-ever-to-utilize-kite-power/18005/ http://newatlas.com/cargill-ship-will-be-largest-ever-to-uti...

Retric 10y ago

These ships are a very poor place for battery's vs cars because of how infrequently they recharge and how efficient their engines are. They extract ~2.5x as much energy from their fuel so the real solution is changing fuels and adding a catalytic converter not battery's. PS: Remember, this pollution has a short half life, so it's simply not around that long.

dredmorbius 10y ago

No. The combined power and capacity constraints make solar a nonstarter. Specialised, high-efficience, very light, all-electric boats have been built. They top out at about six knots, roughly 1/4 the speed of most shipping of the 1980s and 1990s (more recent ships have slowed somewhat to about 18-20 kt for efficiency, called slow steaming). We had a technology for low-fuel shipping, it's called sails, and achieved net speeds of 12-20 kt with cargoes. Commercial sail vessels actually operated through the 1940s, in rare cases, as fuel costs and limitations were still concerns. These ships could and did out-pace coal-fired boats. They are, however, dwarfed by modern monsters such as the Emma. https://en.m.wikipedia.org/wiki/Gustaf_Erikson https://en.m.wikipedia.org/wiki/Gustaf_Erikson https://en.m.wikipedia.org/wiki/Windjammer https://en.m.wikipedia.org/wiki/Windjammer

deleted 10y ago
[deleted]
usrusr 10y ago
Thank you for the Wikipedia ride, now I'm kind of waiting for Larry Ellison to enter grain shipping with ocean skimming carbon composite monstrosities ;) (Or at least for a Neil Stephenson novel about that happening)
- dredmorbius 10y ago
  Carbon-composite monstrosities? So ... Clipper Ships? ;-)

jdblair 10y ago

You're using power (MWh) to make your point, but the crucial practical issue is energy storage (MWh). According to this chart[1], bunker fuel has about 80 times the energy density of lithium batteries. Something has to charge those batteries, too, so there will be another fuel source required generate the electricity. Container ships do have large surface area, and its conceivable - it might be practical to build a hybrid solar/diesel ship. I can imagine most of the system being packaged in containers with solar cells on the top, and batteries and inverters inside. They would then be loaded last, on top of of the load and connected to a ship-board motors. 1: https://people.hofstra.edu/geotrans/eng/ch8en/conc8en/energycontent.html https://people.hofstra.edu/geotrans/eng/ch8en/conc8en/energy...

Pxtl 10y ago
The challenge is that container ships don't have a roof over the containers. You'd have to have shipping container sized solar banks placed on top of each container, then wire them into the ship's power system. Every load and unload would add extra time spent unhooking, unloading, reloading, and reconnecting the solar roofs.
- D-Coder 10y ago
  4U solar banks (each one fits over four, or some multiple, of containers). Cuts the annoyance down a bit.
- ams6110 10y ago
  Container ships also sail at night.
  - jdblair 10y ago
    Its why this would purely speculative exercise would be hybrid - it would still need a diesel engine, it would just burn less fuel. Regardless, I expect the cost of running a ship's engine on bunker fuel is so low there's little incentive for this.
jdblair 10y ago

planteen 10y ago

The issue is energy density, not motors. The ship burns 1,660 gal/hr = 6000 L/hr when at "economical speed". The energy density of fuel oil is about 10 kWhr/L. Googling tells me that a journey between China and California by ship takes 2-4 weeks. So for three weeks of economical speed, that is 30 MWhr of energy. That is the size of the largest battery installation in North America, the Tehachapi Energy Storage Project. The batteries will weigh about 25 times more than the diesel fuel would weight (assuming fuel oil at 13,000 Wh/kg and 500 Wh/kg for batteries).

knodi123 10y ago
That calculation is for a purely battery powered vessel. I think the person you replied to was suggesting much lower battery capacity, and running primarily while the sun shines, using non-stored electricity. Still isn't enough, but it's a different calculation.
- Dylan16807 10y ago
  Let's do that calculation. It looks like if you covered the entire surface area of the ship in 100% efficient solar panels then at high noon near the equator you would get just about enough power to run at "economical speed". Put on realistic cells and account for the motion of the sun and you won't have 1/10th the power you want.
  - knodi123 10y ago
    Wow, I wouldn't have thought it could even get that close. But as long as we're spitballing.... If you're running on solar and you are only carrying enough batteries to last through the night, then your ship isn't carrying all that fuel, and the enormous engines to burn it (and, heck, alternators). So the boat will have a lot less mass, and a lot less draft - so you can significantly lower the power requirements. Add a SkySail, and relax your shipping deadlines, and maybe you could make it work? * https://en.wikipedia.org/wiki/SkySails https://en.wikipedia.org/wiki/SkySails
    - 10y ago

bluedino 10y ago

1 Westinghouse nuclear powerplant like used in an aircraft carrier will make 100MW.

macmac 10y ago
There have been nuclear merchant vessels in the past and there are still nuclear ice-breakers around. The nuclear merchant vessels were never a success, due to various challenges, some of the outlined in this article: https://www.flexport.com/blog/nuclear-powered-cargo-ships/ https://www.flexport.com/blog/nuclear-powered-cargo-ships/
- dmoy 10y ago
  Huh the last bit of that article seems very pro nuclear container ship primarily due to oil price instability and environmental concerns. Interesting read though, I wonder if the US's nuclear ship was a decade later and actuallytrying to be commercially viable if we'd have nuclear container ships right now.
hectorr 10y ago
I love nuclear power, but there is a huge gap between how the Navy runs their nuke fleet and how the civilian maritime world operates. Navy nukes are some of the most insanely anal and uptight professionals you will ever meet. It's a zero-defect culture, because it has to be. The job of civil maritime is to provide commodity supply - the only way to make money over the long term is to be a low cost operator. The best (usually Greek) shipowners will milk every last dollar out of an asset, which down in the bilges means fixing boilers with duct tape and bailing wire. That's not how you want to run a nuclear plant.