• @18107@aussie.zone
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    451 year ago

    A hydrogen engine is so much worse for efficiency than a hydrogen fuel cell, and even that is not good compared to batteries. I’d estimate the round trip efficiency of a hydrogen engine to be about 10-15%. So for the same energy that could be used to drive a battery EV 100km, this car from Toyota could drive 12km.

    Additionally, hydrogen is not very energy dense per volume. A compressed hydrogen tank that replaces the boot/trunk of the car would have enough hydrogen for about 100km of range.

    Please let me know if I’m wrong about any of these numbers. For Toyota’s sake, I really hope I’m wrong.

    • @PeterPoopshit@lemmy.world
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      1 year ago

      I thought they were using ammonia powered vehicles and calling them hydrogen just because ammonia contains hydrogen. Wasn’t there a bunch of hype a few months ago about Toyota inventing an ammonia internal combustion engine that was so efficient it would “make electric cars obsolete”? The article just mentioned liquid hydrogen though. So I don’t know what to believe anymore.

    • @Geobloke@lemmy.world
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      31 year ago

      I think the biggest thing that people forgot in the efficiency debate is cost. What will hydrogen actually cost to go 100km compared to electricity

      • @18107@aussie.zone
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        1 year ago

        The current cost to drive a car with green hydrogen from electrolysis (not blue or grey hydrogen from methane reforming) is roughly equivalent to $50/L (AUD) for petrol, or $120/Gal (USD) for gas. This is one of the reasons most hydrogen today is made from fossil fuels.