The relocation was the big question on my mind.
The other is: when will they charge? Does this ship not run at night?
The other is: when will they charge? Does this ship not run at night?
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.
So ”only” 42 car sized chargers for a massive boat, there are probably some massive Tesla superchargers sites that approach that.
> 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.
Big difference, since I imagine the turnaround time on a similar ICE ferry would be less than 40 minutes but more than 10.
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.
People who charge electric vehicles at home emphasise that you plug it in as a matter of routine every night (ABC: Always Be Charging) and since it's software-controlled, you can e.g. tell it to charge up to 80%, and figure out the most cost-effective way to do that by 8am.
The ABC of such a ship, is that it would be plugged whenever it is docked, during the turnarounds. And there is enough time in that turnaround to keep charge. It likely also has some downtime at night as well, but that matters less in this case.