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You seem to be trying to make a point while ignoring the fact that your point has been explicitly addressed by the article you are attempting to discus (apparen

by shkkmo 4y ago

You seem to be trying to make a point while ignoring the fact that your point has been explicitly addressed by the article you are attempting to discus (apparently without having read it). FTA: > Past work has suggested that battery electrification of marine vessels is unfavourable given the low energy density of batteries relative to hydrocarbon fuels28,29,30,31. However, their assumptions about battery energy density and cost are outdated, differing in some cases by one to two orders of magnitude from today’s best-available figures of 210 Wh kg−1 specific energy32 and US$100–134 kWh−1 (ref. 33). Furthermore, these studies assumed that the maximum battery capacity is limited by the existing onboard space dedicated to mechanical propulsion systems and fuel storage, so their findings suggest that battery-electric ships would require several recharges to traverse even short routes. > For example, for a 5,000 km range small neo-Panamax ship, we estimate that a 5 GWh battery with lithium iron phosphate (LFP) chemistry, with a specific energy of 260 Wh kg−1 (ref. 34), will weigh 20,000 t and increase the draught by 1 m—a small fraction of the ship’s total height and well within the bounds of the vessel’s Scantling (maximum) draught. For voyages longer than 5,000 km, the increase in draught exceeds the vessel’s Scantling draught. > We find that minimal carrying capacity must be repurposed to house the battery system for most ship size classes and along short to medium-length routes. For a small neo-Panamax containership, representing an average containership in the global fleet, the volume required by the battery system is less than the volume currently dedicated to the ICE and fuel tanks for routes under 3,000 km. For the longest modelled route of 20,000 km for this ship class, the battery would occupy 2,500 twenty-foot equivalent unit (TEU) slots or 32% of the ship’s carrying capacity. Supplementary Table 1 provides the baseline values used for each ship class. > In the baseline scenario, the TCP of a battery-electric ship is lower than that of the incumbent ICE vessel only for ship classes larger than 8,000 TEUs over voyages of less than 1,000 km (refs. 5,40,47,49,50). Over longer voyages, the additional cost of the battery system, increased power requirements and charging infrastructure outweighs the savings from fuel switching and the efficiency gains of direct electrification. However, if the environmental costs of NOx, SO2 and CO2 are considered, the cost-effective range increases to 5,000 km across all size classes given the high emissions rates of HFO relative to the emissions intensity of the US grid.

LeChuck 4y ago
A typical Panamax ship has a DWT of approximately 55000 t (more actually, but this is roughly the max in order to transit the Panama Canal). It's not tenable to sacrifice more than 1/3 of that for batteries. And this for a range of not even 3000 NM!
- nicoburns 4y ago
  It's also not tenable to continue emitting CO2 at the levels we currently are. So something's going to have to give. It may end up being that we ship less things, and that shipping becomes more expensive. We can't just assume that we will be able to continue to consume at the levels that we currently do.
- shkkmo 4y ago
  You must have read too quickly. The section of the article I quoted says that 3000 km range requires LESS space than is currently used for ICE engines and fuel so no carrying capacity is lost. It is for a 20,000 km that a third of the cargo space needs to be dedicated to batteries. Again, the article goes into all of this. If you want to discuss this productively, you need to read the article and criticism where their assumptions, model, or calculations are flawed.
  - LeChuck 4y ago
    I was talking about 3000 nautical miles, which is a bit more than 5000 km. The section above the one you're referencing. > For example, for a 5,000 km range small neo-Panamax ship, we estimate that a 5 GWh battery with lithium iron phosphate (LFP) chemistry, with a specific energy of 260 Wh kg−1 (ref. 34), will weigh 20,000 t [...]. Even then, a ship with 5000 km range is only useful in very limited circumstances. 3000 km range is almost useless.
    - shkkmo 4y ago
      Again, this is already covered by the article: > The sector’s trend towards containership gigantism has promoted a hub-and-spoke model of trade, whereby high-capacity mega-containerships transport goods over long distances from one hub to another54. From the destination hub, a host of smaller feeder ships transport the containers to their final destinations in smaller regional ports. Nearly all of these feeder ships traverse short routes that could be electrified, which would increase battery-electric containership adoption well beyond the potential suggested by intraregional trade figures. Figure 5 depicts the ten best-connected ports in the world, all of which are intraregional routes less than 5,000 km in length2. Moreover, feeder ships are older on average than their larger-capacity counterparts, and many are reaching the end of their useful service lives56. The 2020 IMO regulation limiting sulfur content will probably lead to the premature scrapping of these fuel-inefficient ships, creating an opportunity for battery-electric models to enter the fleet57. > Although containerships, with their standardized cargo and volume dependency, are useful for understanding the technoeconomics of battery-electric shipping, they represent only 23% of total maritime shipping emissions58. Achieving larger emissions reductions will require electrifying additional ship types, including oil tankers, bulk carriers, general cargo ships and cruise liners. Of those, bulk carriers and oil tankers seem to have the largest emission footprint. Unlike containerships, some of these ship types are primarily constrained by weight rather than volume41. Energy density by weight is therefore the critical technical parameter for the batteries that would power these ships.

by shkkmo 4y ago

LeChuck 4y ago

A typical Panamax ship has a DWT of approximately 55000 t (more actually, but this is roughly the max in order to transit the Panama Canal). It's not tenable to sacrifice more than 1/3 of that for batteries. And this for a range of not even 3000 NM!

nicoburns 4y ago
It's also not tenable to continue emitting CO2 at the levels we currently are. So something's going to have to give. It may end up being that we ship less things, and that shipping becomes more expensive. We can't just assume that we will be able to continue to consume at the levels that we currently do.
shkkmo 4y ago
You must have read too quickly. The section of the article I quoted says that 3000 km range requires LESS space than is currently used for ICE engines and fuel so no carrying capacity is lost. It is for a 20,000 km that a third of the cargo space needs to be dedicated to batteries. Again, the article goes into all of this. If you want to discuss this productively, you need to read the article and criticism where their assumptions, model, or calculations are flawed.
- LeChuck 4y ago
  I was talking about 3000 nautical miles, which is a bit more than 5000 km. The section above the one you're referencing. > For example, for a 5,000 km range small neo-Panamax ship, we estimate that a 5 GWh battery with lithium iron phosphate (LFP) chemistry, with a specific energy of 260 Wh kg−1 (ref. 34), will weigh 20,000 t [...]. Even then, a ship with 5000 km range is only useful in very limited circumstances. 3000 km range is almost useless.
  - shkkmo 4y ago
    Again, this is already covered by the article: > The sector’s trend towards containership gigantism has promoted a hub-and-spoke model of trade, whereby high-capacity mega-containerships transport goods over long distances from one hub to another54. From the destination hub, a host of smaller feeder ships transport the containers to their final destinations in smaller regional ports. Nearly all of these feeder ships traverse short routes that could be electrified, which would increase battery-electric containership adoption well beyond the potential suggested by intraregional trade figures. Figure 5 depicts the ten best-connected ports in the world, all of which are intraregional routes less than 5,000 km in length2. Moreover, feeder ships are older on average than their larger-capacity counterparts, and many are reaching the end of their useful service lives56. The 2020 IMO regulation limiting sulfur content will probably lead to the premature scrapping of these fuel-inefficient ships, creating an opportunity for battery-electric models to enter the fleet57. > Although containerships, with their standardized cargo and volume dependency, are useful for understanding the technoeconomics of battery-electric shipping, they represent only 23% of total maritime shipping emissions58. Achieving larger emissions reductions will require electrifying additional ship types, including oil tankers, bulk carriers, general cargo ships and cruise liners. Of those, bulk carriers and oil tankers seem to have the largest emission footprint. Unlike containerships, some of these ship types are primarily constrained by weight rather than volume41. Energy density by weight is therefore the critical technical parameter for the batteries that would power these ships.