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Comment by evilos | Hacker News Reader

The 5000km range barge needs a 6.5 GWhr battery, which is the equivalent of 130,000 base range model 3s.

That's a lot of batteries. Not sure if that much industrial capacity will be available soon enough.

Also, I'd really really hate to be the person that has to fight a marine fire on board the 6.5 GWhr battery barge.

I wonder if you could design a keel with semi-permanent "slots" for the battery packs. They're going to weigh an incredible amount, so they'll probably need to be as low as possible, and partial surface contact with the ocean would help with the incredible cooling requirements. Fire starts, pod immediately drops into the ocean?

There's no real way to put out a lithium fire of that size, even if you extinguish it, it may start again days later. Has to go overboard one way or another.

Dangerous energy source at the bottom of the ocean? Do you want Godzillas? Cuz that’s how you get Godzillas.

or you could just put them in containers and do a battery swap as part of the loading/unloading

Lithium seems like a bad fit all-around. Plus, just charging all those batteries would put a ton of local strain on the grid. I think this would be an ideal situation for liquid flow batteries. Those seem like only a matter of time, I don't think there is any chemistry /physics reasons preventing their commercial adoption, just engineering.

Would it be a lot worse than a ship storing the equivalent energy in combustible liquid fuel?

Yes, lithium fires are a LOT worse.

Lithium ion, sure. There are other chemistries, such as LFP, where thermal events aren't nearly as exciting.

A container ship would use the equivalent of 641825 BMW 3 series of fuel for that trip. Though one would use premium and the other bunker fuel.

Math based on 2500 gallons per mile for a 3106 mile trip, converted to km and liters, then divided by a 55 liter tank.

Video of single passenger bus lithium battery fire:

http://www.jimstoneindia.com/pagesq22022/page2v.html

That's extremely impressive, I've seen videos where people combust lithium cell phone batteries and it's a lot, but roughly how much megawatt hours of capacity go into running a bus by comparison?

Note: this video is sped up to look more dramatic.

No, thats a GAS bus fire!

Do you have some source for this?

According to the linked website:

> This video features an electric bus with a new type of lithium polymer battery

The author seemed to assume there is no ecological costs to extracting, processing, and shipping massive amounts of rare earth around the oceans, and, as you point out, that they never suffer mishaps

> ...massive amounts...

The entire world production of neodymium was on the order of 80k ton/yr the last I checked (though that was quite a few years ago).

How many tons of earth need to be processed to end up with 80k tons of neodymium?

There are massive ecological costs to extracting, processing and shipping even more massive quantities of dinosaur juice around the oceans, and they suffer "mishaps" quite frequently.

Frankly, we're in much deeper shit if we continue to add carbon to the carbon cycle, and while strip mining the earth for precious metals isn't ideal, we don't have many other choices. Still waiting on at-scale biofuels.

Electrification reduces the amount of mining and extraction and transport so if that's your focus you should be excited for this.

The key difference being that once you extract it, you can first re-use it for decades, then recycle it. Whereas with fossil fuels you need to continually dig up more to replace the ones you burned and vented into the atmosphere then ship it to where it is used.

https://www.transportenvironment.org/discover/electric-car-b...

Moat of the discussion is based on storing enough power to last the whole journey. What about providing floating supply stations where they could charge or exchange batteries?

The ocean is a harsh and very variable place. I have see a video of a ship refueling while underway with a tanker, you could do something similar but you need a way to recharge the electric tanker.

Those materials are not consumable that’s what make the most difference.

For sure, there is some pollution involved in extraction of the elements, but you do it once.

Contrast that with oil where you burn it and it’s done, you start over.

Electrification start with cars, then planes, then ships unless there is major breakthrough that reduce the cost of batteries.

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