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Comment by pzo | Hacker News Reader

I think another problem is how fast you will be able to charge such a huge battery and how expensive such ship battery charger will be and if you expect to have such charger at most ports (ideally for every docked ship). Will you even need a power plant at every port?

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You'd need big batteries in the port to act as a buffer and enough energy to charge those in between when no ships are docked. But the ship would be there for quite some time (up to a day or even more). So a few tens/hundreds mw of power would go a long way.

You'd probably want to use a mix of local wind/solar power and a grid connection. Of course, harbors usually already have lots of infrastructure to power heavy industry (steel, refineries, etc.) and transport (e.g. rail). This just adds to that.

There are also other solutions including using container batteries and simply swapping in fresh ones. Which especially in a container harbor shouldn't be that big of a deal.

Heavy oil is almost a waste byproduct of oil refinery, could be found anywhere and quite cheap: 500$ per tonne, 500$ per 40GJ of energy.

Pretty sure electric ships are not coming anywhere near long haul shipping. However for anything close to shore - it's a real future: tugboats, bunkers, tourist boats etc.

If the demand for other oil products starts to drop due to EV prevalence, there might be less byproducts.

Somehow I'd imagine that you could have container size and shape batteries and maybe even stop more often in ports to swap them out using existing crain mechanisms

2.7GWh / 24h ~= 100MW. That's SMR territory per ship, or a proper nuclear power plant if a few of them charge at the same time from empty to full, assuming they aren't all empty at the same time...

That kind of load is roughly comparable to what a modern rail network consumes. We're talking heavy transport here, of course it consumes power. The London underground consumes something like 1.2twh per year. Peak loads of around 150 mw. It's very comparable.

Harbors are already very large consumers of power. Sure, this adds to that demand but if you think about all the cranes, heavy industry, refineries, freight trains, etc. you can get to a few hundred mw easily. Adding more would definitely need planning. But it's not so dramatic. This just sounds like a good reason to invest in power generation.

Charging big battery takes the same amount of time as charging small battery if charger's power is proportionally larger. E.g. charging Tesla at Supercharger takes same amount of time as charging phone using fastest phone charger.

I don't think you can just take tesla supercharger and scale it that easily to use in ships. You have to think how thick charging cables you have, how many of those you need to connect to your ship, how heavy they are, how long they are, how much heat the generate. Remember such battery would be many orders of magnitude bigger than in tesla. Tesla charger cable is many times order thicker than your usb charging cable. Now imagine many times order thicker ship charging cable and how heavy it is, how less elastic it is, how much heat generates, how much isolating cover needs (for heat, protection, magnetic field).

Scaling won't be hard - worst case you could just install 1000 250 kilowatt superchargers on the dockside, plug them all in and get 250 megawatts.

Obviously there are better solutions, but that solution demonstrates feasibility with no further engineering work required.

Yes, this is true. Realistically, a "charging station" for a ship this size would have a large pierside structure to transform/regulate, and a very large cable array that would probably be moved to the ship via a crane. The connectors would almost certainly require manual fitup and the operation would require several personnel.

(Similarly, refueling a ship is substantially more complicated than refueling an automobile.)

Maritime engineers and workers can get this job done.

You could increase the battery pack voltage and/or charge several packs in parallel. Why not have 20 charging cables. Shouldn't be a problem for a ship. Would of course be fairly inconvient for a car.

There already exist purpose-built chargers for electric ships. See, for example, https://www.stemmann.com/en/products/charging_systems/ferryc...

To support a 48 hour recharge of the battery hypothesized upthread, you would only need to scale up this system by about 10x. Or attach 10 along the length of the ship. Or some combination of those options.

This is a non-problem.

Edit: Excuse me, but I misread the brochure. The existing system need be only scaled up by a factor of 2.5x to recharge a container ship in 48 hours.

They spend like a day at port so there is a bit of time to load. The logistics of getting the power to the port gonna be harder, as it's literally hundreds of megawatts to load it at reasonable rate

Stick the batteries in containers and you just swap them and load them whenever it is convenient.

That is a neat solution that would make it part of the standard physical interface of the port.

All of the machinery is already designed to handle containers so it just becomes another type of container.

Very spicy containers if they get damaged.

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