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Comment by jk2323 | Hacker News Reader

> Since pure battery electrics will always have lower operating costs (if the hydrogen is produced from electricity and not oil/gas)

There are other options. You can producte H2 directly from sunlight. https://setis.ec.europa.eu/setis-reports/setis-magazine/fuel...

And we might run out of Lithium. Or Cobalt. Or Vanadium. I doubt that we run out of Hydrogen.

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The point is - it's neither one nor the other: Combining working fuel cell technology with batteries really gives the best of both worlds:

- Batteries are the most efficient in the long run and very dynamic at power release, but they are heavy (more than half the weight of Tesla's truck is the batteries), use lots of rare resources and take pretty long to recharge. It's getting better, but if you really want to drive a few thousand miles with short fuel breaks in an emergency, you can't.

- Hydrogen fuel cells suck at dynamic release, they really want to have a constant power draw. They're less efficient than batteries, but you can refuel quickly and don't have to carry the fuel weight with you all the time.

Taking all the technical challenges of storing hydrogen and making efficient fuel cells aside for the moment, combining the two technologies is really awesome in a way. You can get rid of two thirds of the batteries — and suddenly you have a car that's all of: easy to instantly refill, still dynamic to accelerate and overtake on the highway due to the batteries, but you also just have to dimension the fuel cell for average, not for peak power draw.

Considered the hydrogen is CO2 neutrally generated, it's really the optimum solution.

> if you really want to drive a few thousand miles with short fuel breaks in an emergency, you can't.

What kind of emergency would involve driving a few thousand miles quickly? I can only see a few hundred (hurricane evacuation).

At those distances, why wouldn't you fly?

Current hydrogen fuel cells contain platinum. The tech inside the Toyota Mirai contains about 30g if I remember correctly. So, which earth element do you prefer to run out of? :)

We can literally sweep platinum off our highways, as Cody'sLab demonstrates[0]. Platinum is a catalyst in auto mufflers to change NOx molecules back to N2 and CO2. And a tiny amount flakes off as a gas-car drives. Sweeping a 10-foot section of heavily-used freeway shoulder netted them $0.55 of platinum. At this rate, there should be $1000 of platinum per mile of freeway shoulder.

[0] https://youtu.be/v5GPWJPLcHg

Yeah, thats an interesting option. Still remains to be seen if that’ll actually be cheaper. Sounds like something that is harder to decentralize than electrolysis, which can be a downside. With electrolysis you can make the hydrogen on-site.

Lithium-cobalt is not the only chemistry. I’m optimistic about alternate chemistries in the long term. Especially now that the battery market is growing so rapidly. There are massive investments in research.

I doubt we’ll run out though. They’re not that rare. Besides, it’s a renewable resource, not a combustible one.

http://periodictable.com/Properties/A/CrustAbundance.al.html

From that link platinum is 3.7E-6, others [Li, V, Co] are O(2E-3), or more, by percentage of Earth's crust.

The prevalence in crust doesn't really matter, what matters is how much is actually in recoverable ores. Rare earth elements, despite their names, are actually reasonably common: about as common as tin or cadmium. Hell, cerium is more common than copper. They're called rare earth elements in part because it's hard to find a high enough concentration to extract and in part because they're so hard to separate from each other.

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