5 ms·

How long would it take to charge the batteries?

jacquesm 5y ago
That is a very good question. I tried to find you an answer but the only bits about the charging that I could find is that it is fully automatic and that they expect it to happen during the unloading or loading, but not how long that would take.
- guerby 5y ago
  Video of robotic plug: https://www.youtube.com/watch?v=Kc2CBGVa_kw https://www.youtube.com/watch?v=Kc2CBGVa_kw Worlds largest electric ferry connecting to a automatic robotic charger station Here it says "5 minutes" for charging (15 minutes trip): https://press.siemens.com/global/en/feature/pioneer-position-green-solutions-shipbuilding-industry https://press.siemens.com/global/en/feature/pioneer-position... "At nearly 98 meters long and 16 meters wide, the Elektra can transport up to 90 cars per trip. The ferry purchased by FinFerries will now be traveling this route every 15 minutes. The batteries will be charged in roughly five minutes while cars move off and onto the ferry. The two lithium-ion batteries each have a capacity of 530 kWh. "
  - jacquesm 5y ago
    So this one having 7 times larger batteries charged via the same connection would charge in a bit over 30 minutes on a trip like that, and on the route that it is planned for probably more like several hours, which seems reasonable given that they also need to load and unload.
Mengkudulangsat 5y ago
If you have one charge point at the loading dock and another charge point at the unloading dock (and charge the ship during the average loading / unloading times).. theoretically you can estimate the max range between the two docks where you never have to worry about charging.
- jacquesm 5y ago
  Well, you'll never have to worry about charging anyway, but ships that don't move are losing money so ideally charging would not add to the turn-around time. I think it is the money that the owners would be worrying about. 7 MWh is a pretty beefy battery, I am going on the assumption that its size was carefully chosen to give it sufficient capacity during the operating life of the vessel to serve its route. Filling that up from an industrial drop at 20KV with 100A is doable in under four hours.
  - lallysingh 5y ago
    I wonder how much money is saved in fuel and maintenance.
    - jacquesm 5y ago
      It may well be that the decision to go uncrewed was given in by either higher purchase price or higher operating costs so they had to do one more thing to make the ship competitive. But making an electric ship uncrewed is feasible, doing that with a diesel would be a little bit more tricky, boats that size are - unsurprisingly, I guess - mechanically quite complex. In this case they 'crew' the boat from the shore, which will probably work well as long as conditions are good, but I'd hate to be in the driving seat of one of those and to see the comms link go down.
pengaru 5y ago
At least it won't be difficult to keep them cool, with all that seawater at the ready.
eitland 5y ago
Most new ferries in Norway seems to use batteries these days and last time I was on the west cost back in September I made sure to look at it. It seems they attach a charger while they lower the ramp fir unloading and disconnect it just before leaving. The unload / load process seemed as fast as before to me but I haven't used ferries a lot since before covid. I also guess they might do slightly longer maintenance charging cycles at night since there are fewer departures then.
- jonsen 5y ago
  I don't get why they don't have roll-on roll-off batteries. It's a ferry after all. Plenty off time to charge then.
  - fulafel 5y ago
    The cost savings from slow charging would need to be really big to offset the cost of having 2x as many batteries and operating the logistics of battery shuffling.
    - jonsen 5y ago
      2x as many batteries would last 2x as long. Maybe longer when charged more slowly. I read about maybe the first electric ferry, that the grid could not supply the power demand when speed charging the ferry. A new power line with greater capacity was then build. Grid operations are generally better off with lower peak demands.

That is a very good question. I tried to find you an answer but the only bits about the charging that I could find is that it is fully automatic and that they expect it to happen during the unloading or loading, but not how long that would take.

guerby 5y ago
Video of robotic plug: https://www.youtube.com/watch?v=Kc2CBGVa_kw https://www.youtube.com/watch?v=Kc2CBGVa_kw Worlds largest electric ferry connecting to a automatic robotic charger station Here it says "5 minutes" for charging (15 minutes trip): https://press.siemens.com/global/en/feature/pioneer-position-green-solutions-shipbuilding-industry https://press.siemens.com/global/en/feature/pioneer-position... "At nearly 98 meters long and 16 meters wide, the Elektra can transport up to 90 cars per trip. The ferry purchased by FinFerries will now be traveling this route every 15 minutes. The batteries will be charged in roughly five minutes while cars move off and onto the ferry. The two lithium-ion batteries each have a capacity of 530 kWh. "
- jacquesm 5y ago
  So this one having 7 times larger batteries charged via the same connection would charge in a bit over 30 minutes on a trip like that, and on the route that it is planned for probably more like several hours, which seems reasonable given that they also need to load and unload.

Mengkudulangsat 5y ago

If you have one charge point at the loading dock and another charge point at the unloading dock (and charge the ship during the average loading / unloading times).. theoretically you can estimate the max range between the two docks where you never have to worry about charging.

jacquesm 5y ago
Well, you'll never have to worry about charging anyway, but ships that don't move are losing money so ideally charging would not add to the turn-around time. I think it is the money that the owners would be worrying about. 7 MWh is a pretty beefy battery, I am going on the assumption that its size was carefully chosen to give it sufficient capacity during the operating life of the vessel to serve its route. Filling that up from an industrial drop at 20KV with 100A is doable in under four hours.
- lallysingh 5y ago
  I wonder how much money is saved in fuel and maintenance.
  - jacquesm 5y ago
    It may well be that the decision to go uncrewed was given in by either higher purchase price or higher operating costs so they had to do one more thing to make the ship competitive. But making an electric ship uncrewed is feasible, doing that with a diesel would be a little bit more tricky, boats that size are - unsurprisingly, I guess - mechanically quite complex. In this case they 'crew' the boat from the shore, which will probably work well as long as conditions are good, but I'd hate to be in the driving seat of one of those and to see the comms link go down.

pengaru 5y ago

At least it won't be difficult to keep them cool, with all that seawater at the ready.

eitland 5y ago

Most new ferries in Norway seems to use batteries these days and last time I was on the west cost back in September I made sure to look at it. It seems they attach a charger while they lower the ramp fir unloading and disconnect it just before leaving. The unload / load process seemed as fast as before to me but I haven't used ferries a lot since before covid. I also guess they might do slightly longer maintenance charging cycles at night since there are fewer departures then.

jonsen 5y ago
I don't get why they don't have roll-on roll-off batteries. It's a ferry after all. Plenty off time to charge then.
- fulafel 5y ago
  The cost savings from slow charging would need to be really big to offset the cost of having 2x as many batteries and operating the logistics of battery shuffling.
  - jonsen 5y ago
    2x as many batteries would last 2x as long. Maybe longer when charged more slowly. I read about maybe the first electric ferry, that the grid could not supply the power demand when speed charging the ferry. A new power line with greater capacity was then build. Grid operations are generally better off with lower peak demands.