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Comment by jonwest | Hacker News Reader

What about using hydrogen as a generator for an EV like in the Hyundai 74 concept? I’m far from an expert but something like that, at least intuitively, feels like a nice compromise with having portability of fuel, but still allowing for alternative power sources via electricity (like if grid power was sourced via solar, hydro, wind, etc).

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I don't understand what problems the Hyundai 74 is trying to solve. It has roughly the same stats as a long range model 3 for acceleration and range, but has to carry around both a fuel cell and a 60+ kwh battery (nearly as large as the model 3's). Hydrogen mpge is already terrible (all hydrogen mirai has 75 compared to long range model 3 at 130), and an extra step here is only going to make it worse.

Is there something I'm misunderstanding about the vehicle's platform?

refill vs recharge

Looks like the worst of both worlds at the first glance. However depends by the costs of batteries. In a world with an abundance/excess of green energy but expensive batteries to store it hydrogen makes sense. The conversion of electricity->hydrogen->electricity is quite inneficient so batteries better be cheap enough otherwise we will go the hydrogen way for cars as well.

I think you’re under the impression that it requires the hydrogen generator? You can use the hydrogen tank if you are without somewhere to charge the vehicle, but you can also just use it as a traditional EV and charge as you normally would.

Both hydrogen and batteries are energy storage technologies. My point is that it doesn't make sense to use one technology if the other is cheaper.

If batteries are too expensive then you would have an electricity -> hydrogen conversion at the power plat/wind farm.

Why not add a gas engine too, for places where you only have gas and not electricity or hydrogen? Because it's unnecessary weight to carry around. Toyota and Japan pushed hydrogen for a long time because their industrial base is so focused on gas/diesel drive trains. Their vast investments and expertise will be worthless as we leave it behind. They've also never made any progress getting away from hydrogen coming from fossil fuels. h is not a great fuel source because it's so much less dense than carbon fuels, you can't get far on one tank. It has two benefits, easy to refuel, and burning it doesn't produce pollution, but the negative of coming from fossil fuels kills it.

Hydrogen makes no sense for passenger vehicles. It requires building out a massive infrastructure that doesn't exist and is just far less efficient than storing the elecricity in a battery.

Check out this video for more on where Hydrogen does and does not make sense: https://youtu.be/JlOCS95Jvjc

Now what happens as soon as there _is indeed_ sufficient H2 refuelling infrastructure for trucks? (Assuming that it will happen for long haul trucks because BEV trucks will not replace diesel powered ones in the long term)

Doesn't that make FCEV cars look a lot more convenient than BEV cars?

Fuel cells in the vehicle would be much more efficient. Combustion generators in the car have storage issues and efficiency issues. liquid hydrogen needs cryogenic storage, compressed hydrogen isn't space efficient relative to the output. Combustion generators at home would suffer from the same storage problems as in cars.

https://youtu.be/vJjKwSF9gT8

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