Fire hazards are there for any fuel, Safety systems evolve to handle them. The environmental impact would be more localized than an oil spill.
Assuming two days available to charge the vessel, you'd need about 100MW continuous. Not trivial, but doable.
As far as battery fires go, sure, but a) there are already a lot of electric ferries in service so designing safe maritime battery packs isn't a new challenge and b) the alternative isn't exactly risk free either; we've seen plenty of oil spills from ships.
I can only imaging how hard it is to put out a ship fire, but is there any reason to see that the situation would be different? Bunker fuel appears to be less flammable.
Petrol cars at most marginally more likely to catch fire, if at all. They cannot catch fire by simply being submerged in a foot of water, like an EV can. They are far easier to extinguish than EVs, which are practically unextinguishable and can reignite weeks or months later. You can use a fire extinguisher on a petrol car fire if you catch it early (they are usually electrical fires). If you catch an EV fire early, your best course of action is to run away as fast as possible.
Ships are not known to be subject to fires because the types of fuel they use are not generally so volatile, and they are literally surrounded by water which can be pumped to the deck or wherever to drown any fire. Some use diesel, which is difficult to light even with a match. Others use heavy crude oil that looks like tar and would be similarly difficult to ignite accidentally. A battery fire on a ship would be a HUGE problem, as we have seen with ships carrying EVs.
I think another often-overlooked risk of EVs is the arson risk. Even if batteries are less likely to catch fire (in the first few years of use, if you baby them), a bad actor can start an unextinguishable fire by shorting out or otherwise igniting a battery pack. This is easy to do and devastating.
“An American insurer found that just 25 out of 100,000 EVs suffer fire damage.
By comparison, 1530 per 100,000 ICE cars experience fire, and hybrid vehicles suffer a much higher risk of 3475 per 100,000 .”
https://www.autocar.co.uk/car-news/electric-cars/how-much-fi...
As I said, the fact that these fires can't be extinguished is a major arson risk, as is their toxicity. Insurers will eventually have to raise their rates to cover the extreme risk posed by EVs. https://www.himarley.com/news/ev-charging-fires-are-rare-but... Storing damaged EVs safely means you need to spread them out like a hundred feet apart or something, so that one of them igniting doesn't start a whole lot of EVs on fire with toxic and inextinguishable flames. There are no solutions to these problems after having EVs on the market for several years, because it's a very hard problem to solve.
If they were all electric, all of this size, and required a full charge on arrival, you’re talking about (very roughly) 1 GW continuous power requirement for charging the ships. That’s a lot; no bones about it, but it’s not unprecedented - aluminium smelters and data centers are similarly hungry for power.
Using containerized energy that can be offloaded and charged and swapped at ports is much more efficient way to spread the cost and infrastructure and safety around the world.
There are many ports where you really don't want any form of radiation/nuclear materials available.
You power this the same way you power aluminum smelters - you have a big honking grid connection and build the generation capacity in places with more room.
https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2023-04/...
https://old.reddit.com/r/electricvehicles/comments/1m8wlou/e...
To power your house (or, more generally, supply vaguely sine-wave like output at a constant voltage), you need a converter that will convert DC at the battery voltage to AC at the desired voltage. If a buck converter is used, for example, the AC voltage can only ever be lower than the battery voltage. If you use a cheap square wave inverter, it’s possible that the output and input voltages must actually be equal.
A motor, though, is a highly inductive load, and large motors will and do operate from truly gnarly supply waveforms as long as the current waveform is approximately correct. Industrial VFDs (variable frequency drives) do unspeakable things involving switching a DC bus voltage across the motor via H bridges at tens of MHz, which is a horrible thing to do the the wiring between the drive and the motor if it’s not extremely short. (There are, recently, some guidelines that specific types of wire with twisted conductors, better than average insulation, and high quality shields should be used to improve tolerance of the fact that rather impressive standing waves can appear in the wiring if the wiring is a quarter wavelength or longer.). I can easily imagine designing a VFD that works just fine over a respectable range of DC input voltages by adjusting its duty cycle accordingly.
One way to think of this is that a VFD looks kind of like a buck converter where the inductor is free in the sense that it’s already right there in the motor. If it’s designed right, it will handle the battery’s full voltage range, and the inductor will still be free :)
I imagine it's not the waveform or current that matters so much, as the voltage. These motors would be powering massive blades encountering incredible resistance, so you need megavolts to move them, with an input voltage all the way down to near zero.
> H bridges at tens of MHz
Imagine the MOSFETs on this thing! Do they have something that scales up to MV? That sounds like an engineering challenge in itself.
Full disclaimer: electronics is not my wheelhouse, though I have played around with motor controllers.