4 ms·

The relocation was the big question on my mind. The other is: when will they charge? Does this ship not run at night?

by wepple 9mo ago

pjc50 9mo ago
Also: installing the charging infrastructure. Special docking requirements for the non electric Spirit Of Tasmania were a big problem.
robin_reala 9mo ago
If it’s anything like the electric ferries that cross the Öresund beween Helsingborg and Helsingør, they grab charge while they’re unloading and loading at each terminal: Each trip consumes approximately 1,175 kWh, which is nearly the same amount a residential home consumes in a month. In each port is a tower with a robot arm that connects the charging cable automatically every time the ship comes to the dock. The system charges 10.5 kV, 600Amp and 10.5MW. The batteries have a total capacity of 4,160 kWh, which means that we always have a surplus of electricity if for some reason we cannot load during a stop or if the transit takes more time than usual. In Helsingör the ferries charge for approx. 6 minutes and in Helsingborg the ferries charge for approx. 9 minutes. This is enough to suffice for the journey across the strait.[1] Side note: you can also charge your car on board from the boat’s batteries. [1] https://www.oresundslinjen.com/about-us/sustainability https://www.oresundslinjen.com/about-us/sustainability
- leoh 9mo ago
  10.5MW on demand is wild
  - jasonwatkinspdx 9mo ago
    So in the Fully Charged video about this ship, the shipyard CEO just casually mentions the customer is looking at having 40 MW at each end.
    - M95D 9mo ago
      It would also be interesting to know how they plan to balance the grid when the ship plugs is.
  - phire 9mo ago
    It’s not that big when you consider many DC car chargers can deliver 0.25 MW. So ”only” 42 car sized chargers for a massive boat, there are probably some massive Tesla superchargers sites that approach that.
  - iancmceachern 9mo ago
    The Cruise Ship Terminal in San Francisco has 12 mW. Apparently it's uncommon in that it's wired with enough power available so the cruise ships don't have to run their on board generators while docked in port here. It's a major pollution thing.
SideburnsOfDoom 9mo ago
Q: > when will they charge? A: > The ship... will travel between the ports of Buenos Aires, Argentina, and Colonia del Sacramento, Uruguay. The two cities are 60 kilometers apart, a distance it is expected to travel in 90 minutes. > Direct-current charging stations will be installed at each port... A full charge is expected to take just 40 minutes. https://spectrum.ieee.org/electric-boat-battery-ship-ferry https://spectrum.ieee.org/electric-boat-battery-ship-ferry
- bryanlarsen 9mo ago
  Full charge is 40 but the charge for each journey is 6 / 9 minutes. Big difference, since I imagine the turnaround time on a similar ICE ferry would be less than 40 minutes but more than 10.
  - SideburnsOfDoom 9mo ago
    Indeed, the turnaround time necessary for unloading passengers, and loading the next lot is likely sufficient to keep charge.
    - jillesvangurp 9mo ago
      Something people overlook with these things is that you don't actually need to fully charge batteries because they won't be completely empty and probably a 70-80% charge is more than enough for a single crossing with a healthy safety margin. Also charging speeds are non linear. Charging speeds typically drop when the battery gets closer being full. Charging from 80% to 100% is a lot slower than charging from 20% to 80%. And depending on the battery chemistry, completely discharging or charging them to the max isn't necessarily great for battery longevity. Another point with battery powered ships is that the rate at which they discharge is speed dependent and that's a non linear relationship because the drag increases quadratic with speed. So, if you are at 30%, you can still make it across. Just not at the full speed. This is less about range anxiety than it is about just being able to stick to schedules. If the ship did not charge enough it would have to go slower. But it would still get there. This ship is designed to go quite fast which means it would have a lot of wiggle room. So they might make it across at full speed even at maybe a 60% charge. The risk is that they'd run low and might have to slow down a bit. It would get there but with a delay if that happens. And then it would have to sit there a bit longer recharging leading to more delays. The trick is optimizing the amount of batteries to minimize turnover and delays; not around being able to charge them from 0 to 100%. The sweet spot is probably around the 20-80% mark, meaning you'd want to be able do a crossing at full speed using about 50-60% of the battery capacity. The rest is just there as safety margin to avoid delays. If you burn into that, you need to charge a bit more. With 40-50 minutes turnover, there's plenty of time to do that typically.

The relocation was the big question on my mind. The other is: when will they charge? Does this ship not run at night?

by wepple 9mo ago

The relocation was the big question on my mind. The other is: when will they charge? Does this ship not run at night?

pjc50 9mo ago

Also: installing the charging infrastructure. Special docking requirements for the non electric Spirit Of Tasmania were a big problem.

robin_reala 9mo ago

If it’s anything like the electric ferries that cross the Öresund beween Helsingborg and Helsingør, they grab charge while they’re unloading and loading at each terminal: Each trip consumes approximately 1,175 kWh, which is nearly the same amount a residential home consumes in a month. In each port is a tower with a robot arm that connects the charging cable automatically every time the ship comes to the dock. The system charges 10.5 kV, 600Amp and 10.5MW. The batteries have a total capacity of 4,160 kWh, which means that we always have a surplus of electricity if for some reason we cannot load during a stop or if the transit takes more time than usual. In Helsingör the ferries charge for approx. 6 minutes and in Helsingborg the ferries charge for approx. 9 minutes. This is enough to suffice for the journey across the strait.[1] Side note: you can also charge your car on board from the boat’s batteries. [1] https://www.oresundslinjen.com/about-us/sustainability https://www.oresundslinjen.com/about-us/sustainability

leoh 9mo ago
10.5MW on demand is wild
- jasonwatkinspdx 9mo ago
  So in the Fully Charged video about this ship, the shipyard CEO just casually mentions the customer is looking at having 40 MW at each end.
  - M95D 9mo ago
    It would also be interesting to know how they plan to balance the grid when the ship plugs is.
- phire 9mo ago
  It’s not that big when you consider many DC car chargers can deliver 0.25 MW. So ”only” 42 car sized chargers for a massive boat, there are probably some massive Tesla superchargers sites that approach that.
- iancmceachern 9mo ago
  The Cruise Ship Terminal in San Francisco has 12 mW. Apparently it's uncommon in that it's wired with enough power available so the cruise ships don't have to run their on board generators while docked in port here. It's a major pollution thing.

SideburnsOfDoom 9mo ago

Q: > when will they charge? A: > The ship... will travel between the ports of Buenos Aires, Argentina, and Colonia del Sacramento, Uruguay. The two cities are 60 kilometers apart, a distance it is expected to travel in 90 minutes. > Direct-current charging stations will be installed at each port... A full charge is expected to take just 40 minutes. https://spectrum.ieee.org/electric-boat-battery-ship-ferry https://spectrum.ieee.org/electric-boat-battery-ship-ferry

bryanlarsen 9mo ago
Full charge is 40 but the charge for each journey is 6 / 9 minutes. Big difference, since I imagine the turnaround time on a similar ICE ferry would be less than 40 minutes but more than 10.
- SideburnsOfDoom 9mo ago
  Indeed, the turnaround time necessary for unloading passengers, and loading the next lot is likely sufficient to keep charge.
  - jillesvangurp 9mo ago
    Something people overlook with these things is that you don't actually need to fully charge batteries because they won't be completely empty and probably a 70-80% charge is more than enough for a single crossing with a healthy safety margin. Also charging speeds are non linear. Charging speeds typically drop when the battery gets closer being full. Charging from 80% to 100% is a lot slower than charging from 20% to 80%. And depending on the battery chemistry, completely discharging or charging them to the max isn't necessarily great for battery longevity. Another point with battery powered ships is that the rate at which they discharge is speed dependent and that's a non linear relationship because the drag increases quadratic with speed. So, if you are at 30%, you can still make it across. Just not at the full speed. This is less about range anxiety than it is about just being able to stick to schedules. If the ship did not charge enough it would have to go slower. But it would still get there. This ship is designed to go quite fast which means it would have a lot of wiggle room. So they might make it across at full speed even at maybe a 60% charge. The risk is that they'd run low and might have to slow down a bit. It would get there but with a delay if that happens. And then it would have to sit there a bit longer recharging leading to more delays. The trick is optimizing the amount of batteries to minimize turnover and delays; not around being able to charge them from 0 to 100%. The sweet spot is probably around the 20-80% mark, meaning you'd want to be able do a crossing at full speed using about 50-60% of the battery capacity. The rest is just there as safety margin to avoid delays. If you burn into that, you need to charge a bit more. With 40-50 minutes turnover, there's plenty of time to do that typically.