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Can anyone run the math on how many megawatt hours a full oil tanker might be for comparison? https://transportgeography.org/contents/chapter4/transportation-a

Can anyone run the math on how many megawatt hours a full oil tanker might be for comparison? https://transportgeography.org/contents/chapter4/transportation-and-energy/combustibles-energy-content/ https://transportgeography.org/contents/chapter4/transportat... Is the ratio something like this? 41 to 0.5? 82x?

Manuel_D 3y ago
Sources say 13.7 MWh of energy per ton of LNG. This is in BTUs so at 60% efficiency of a fairly modern gas plant would yield 8.2MWh of electricity generation potential per ton. The largest LNG carrier carries over 80,000 tons of LNG https://en.m.wikipedia.org/wiki/LNG_carrier https://en.m.wikipedia.org/wiki/LNG_carrier So that would work out to 656 GWh of electric generation potential for a full load of the largest LNG carrier. More than 2000x the capacity of the battery carrier.
- Schroedingersat 3y ago
  Now do an LNG tanker the size of a 100TEU feeder ship as an actual comparison.
  - defrost 3y ago
    Indeed, who'd have thought an elephant would be bigger than a mouse. Direct comparison of the largest LNG carrier in existance Vs. early proof of concept "maybe this is worth a shot" vessel isn't especially meaningful. A sensible 'normalised' comparison might be energy carried per displacement kilotonne or some such.
    - Schroedingersat 3y ago
      Answering the original question, it's about 10-20x as much usable energy for the oil. So if there's a wind farm 5% of the distance than an oil farm, the cost of the ship part is a wash.
      - Manuel_D 3y ago
        LNG is 20x the energy for a given volume than Lithium ion batteries. It's 50-60x as much energy for a given mass. The mass is the limiting factor for ocean transportation.
        Schroedingersat 3y ago
        Also false. LNG carriers are volume limited. Hence Q-Max vessels carrying about 100,000 tonnes vs bulk carriers of similar length carrying 400,000 tonnes. Also I said useful energy. Depending on application, electricity is 1.5-5x as useful per joule. Have you considered not just reaching for the stupidest possible lie on every occasion?
        Manuel_D 3y ago
        LNG carrier are volume limited, a freighter carrying bulk lithium ion batteries is mass limited. Have you considered rethinking whether you misread a parent comment before accusing them of "reaching for the stupidest possible lie"? Let's re-read my comment: > LNG is 20x the energy for a given volume than Lithium ion batteries. It's 50-60x as much energy for a given mass. The mass is the limiting factor for ocean transportation. Liquid natural gas is less dense than water, so of course ocean transportation of it is not mass limited. Did it really no occur to you that I was referring to transportation of lithium batteries? Anyway if you doubt that ocean transportation of lithium batteries is mass limited here's some math for you: The biggest freighter has a volume capacity of 24K TEU and a mass capacity of 235,579 tonnes: https://en.m.wikipedia.org/wiki/Evergreen_A-class_container_ship https://en.m.wikipedia.org/wiki/Evergreen_A-class_container_... TEU to volume conversion is inexact, but the most common 20' x 8' x 8'6" container is 33.2 cubic meters. This yields 33.2 * 24K = 796800 cubic meters for our Evergreen Ace. The density of lithium ion batteries is more complicated. Sources say a 18650 battery weights 45g. The dimensions an 18650 are 18mm diameter base and 65mm length, yielding 16.54 cubic centimeters. So mass per cubic meter is 2720Kg, or 2.72 tonnes. If we filled the Evergreen Ace with containers full of lithium ion batteries we'd have 2.72 tonnes per cubic meter * 796800 cubic meters would yield 2,167,296 tonnes versus our DWT of 235,579. We're almost an order of magnitude over weight if we fill out ship to the brim with batteries. Sure, there's nuances like packing efficiency (there's gaps between battery cells), but transportation of lithium ion batteries are overwhelmingly mass limited
  - Manuel_D 3y ago
    Or just compare energy density, directly: https://en.wikipedia.org/wiki/Energy_density#/media/File:Energy_density.svg https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...
    - Schroedingersat 3y ago
      Yes. You could have done that rather than comparing to a ship two orders of magnitude larger. That wouldn't have been a ridiculous attempt to mislead.
Schroedingersat 3y ago
Oil is much more energy dense. Using current gen batteries, this is a cargo of about 1200t for 240MWh Oil would be 13000MWh of chemical energy. Or a replacement for 2000-7000MWh of electricity. It would never be worth transporting electricity from the oil well, but if the option is transporting oil 3000km or transporting electricity from a wind turbine 200km away, the battery-ship is a better use of the ship (but maybe not a better use of the batteries than using a wire).

Manuel_D 3y ago

Sources say 13.7 MWh of energy per ton of LNG. This is in BTUs so at 60% efficiency of a fairly modern gas plant would yield 8.2MWh of electricity generation potential per ton. The largest LNG carrier carries over 80,000 tons of LNG https://en.m.wikipedia.org/wiki/LNG_carrier https://en.m.wikipedia.org/wiki/LNG_carrier So that would work out to 656 GWh of electric generation potential for a full load of the largest LNG carrier. More than 2000x the capacity of the battery carrier.

Schroedingersat 3y ago
Now do an LNG tanker the size of a 100TEU feeder ship as an actual comparison.
- defrost 3y ago
  Indeed, who'd have thought an elephant would be bigger than a mouse. Direct comparison of the largest LNG carrier in existance Vs. early proof of concept "maybe this is worth a shot" vessel isn't especially meaningful. A sensible 'normalised' comparison might be energy carried per displacement kilotonne or some such.
  - Schroedingersat 3y ago
    Answering the original question, it's about 10-20x as much usable energy for the oil. So if there's a wind farm 5% of the distance than an oil farm, the cost of the ship part is a wash.
    - Manuel_D 3y ago
      LNG is 20x the energy for a given volume than Lithium ion batteries. It's 50-60x as much energy for a given mass. The mass is the limiting factor for ocean transportation.
      - Schroedingersat 3y ago
        Also false. LNG carriers are volume limited. Hence Q-Max vessels carrying about 100,000 tonnes vs bulk carriers of similar length carrying 400,000 tonnes. Also I said useful energy. Depending on application, electricity is 1.5-5x as useful per joule. Have you considered not just reaching for the stupidest possible lie on every occasion?
        Manuel_D 3y ago
        LNG carrier are volume limited, a freighter carrying bulk lithium ion batteries is mass limited. Have you considered rethinking whether you misread a parent comment before accusing them of "reaching for the stupidest possible lie"? Let's re-read my comment: > LNG is 20x the energy for a given volume than Lithium ion batteries. It's 50-60x as much energy for a given mass. The mass is the limiting factor for ocean transportation. Liquid natural gas is less dense than water, so of course ocean transportation of it is not mass limited. Did it really no occur to you that I was referring to transportation of lithium batteries? Anyway if you doubt that ocean transportation of lithium batteries is mass limited here's some math for you: The biggest freighter has a volume capacity of 24K TEU and a mass capacity of 235,579 tonnes: https://en.m.wikipedia.org/wiki/Evergreen_A-class_container_ship https://en.m.wikipedia.org/wiki/Evergreen_A-class_container_... TEU to volume conversion is inexact, but the most common 20' x 8' x 8'6" container is 33.2 cubic meters. This yields 33.2 * 24K = 796800 cubic meters for our Evergreen Ace. The density of lithium ion batteries is more complicated. Sources say a 18650 battery weights 45g. The dimensions an 18650 are 18mm diameter base and 65mm length, yielding 16.54 cubic centimeters. So mass per cubic meter is 2720Kg, or 2.72 tonnes. If we filled the Evergreen Ace with containers full of lithium ion batteries we'd have 2.72 tonnes per cubic meter * 796800 cubic meters would yield 2,167,296 tonnes versus our DWT of 235,579. We're almost an order of magnitude over weight if we fill out ship to the brim with batteries. Sure, there's nuances like packing efficiency (there's gaps between battery cells), but transportation of lithium ion batteries are overwhelmingly mass limited
- Manuel_D 3y ago
  Or just compare energy density, directly: https://en.wikipedia.org/wiki/Energy_density#/media/File:Energy_density.svg https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...
  - Schroedingersat 3y ago
    Yes. You could have done that rather than comparing to a ship two orders of magnitude larger. That wouldn't have been a ridiculous attempt to mislead.

Schroedingersat 3y ago

Oil is much more energy dense. Using current gen batteries, this is a cargo of about 1200t for 240MWh Oil would be 13000MWh of chemical energy. Or a replacement for 2000-7000MWh of electricity. It would never be worth transporting electricity from the oil well, but if the option is transporting oil 3000km or transporting electricity from a wind turbine 200km away, the battery-ship is a better use of the ship (but maybe not a better use of the batteries than using a wire).