• Kuinox@lemmy.world
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    1 year ago

    On the other hand, my city is trying hydrogen bus.
    There is a single refilling station needed.

    • JohnDClay@sh.itjust.works
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      1 year ago

      Oh that’s a good idea too. If the hydrogen and electricity is green, it’d have less of an environmental than batteries.

      • Pxtl@lemmy.ca
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        1 year ago

        It isn’t. The amount of green hydrogen is a fraction of a fraction a percent of all hydrogen. The rest is all made from natural gas and the CO2 is released into the air. It’s a green washed fossil fuel.

        • JohnDClay@sh.itjust.works
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          1 year ago

          But if they’re making the stations, they can use or manufacture green hydrogen. It just a matter of the political will.

          • ch00f@lemmy.world
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            1 year ago

            But if they’re making the stations

            But they’re not. See: this article. They’re not profitable, and if they ever were, it was propped up by greenwashing a byproduct of natural gas production.

            • JohnDClay@sh.itjust.works
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              1 year ago

              The article didn’t link. Also, not profitable compared to what? Because running at a slight loss to decrease ghg emissions would still be worth it. Are there fully electric battery alternatives to use instead?

              • ch00f@lemmy.world
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                1 year ago

                I’m referring to the article posted in this post. Stations are being shut down because they aren’t profitable. It doesn’t have to be compared to anything. If they can’t make hydrogen cheap enough, they can’t sell enough and they can’t sustain the business mode.

                The cheapest way to make hydrogen now is as a byproduct of natural gas production which is not as eco-friendly as anybody would hope.

                Hydrogen for consumer use is a boondoggle and waste of time. BEVs are here and work great on existing infrastructure (for L2 charging at least). I drive an EV and exclusively charge it at home. No special station required.

                • JohnDClay@sh.itjust.works
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                  1 year ago

                  Absolutely. That’s what I said originally. Consumer use never made sense. But busses or trains might still make sense since they’d have much more centralized infrastructure.

        • jasory@programming.dev
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          1 year ago

          “Green hydrogen”, is also incredibly inefficient in its own right. Approximately a 70 percent loss of energy compared to 15-20 percent for battery storage. It would literally be just as efficient to burn natural gas in a power station (with a 50+ percent efficiency, modern power turbines are very efficient) and use that power to charge a battery. The entire “hydrogen economy” has been a pipe dream by either complete morons or fraudsters (probably both). (Hydrogen aeroplanes might actually work, but that is by combustion and jet engines are already very efficient).

      • Pipoca@lemmy.world
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        1 year ago

        Today, green hydrogen is essentially an expensive, low-efficiency battery.

        That could change with future work on making more efficient hydrolysis, but today, the numbers really don’t work out on green hydrogen vs alternatives like lithium ion or overhead wires for busses.

        • JohnDClay@sh.itjust.works
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          1 year ago

          But a hydrogen battery has much much better specific energy than lithium ion. So you can have a much longer range.

          • Pipoca@lemmy.world
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            1 year ago

            Hydrogen is very light, so the energy per kilogram is quite high.

            However, hydrogen is also naturally not very dense. Hydrogen at 1 atmosphere has a tiny fraction of the energy of a similar volume of batteries. Pressurized hydrogen is similarly dense to a battery, and liquid hydrogen is about twice as dense.

            So to make hydrogen dense, you need a very thick, heavy tank to hold the pressurized hydrogen. That significantly cuts into your weight advantages.

            Add to that, fuel cells are very inefficient at converting hydrogen to usable electricity.

            • JohnDClay@sh.itjust.works
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              1 year ago

              Maybe I’m missing other conversion factors, but hydrogen has a volumetric energy density of 9MJ/L which is about 2.5kWh/L compared to about 1.7kWh/L for the newest Tesla batteries. So hydrogen is more energy dense than batteries even by volume.