Comment on How to Produce Green Hydrogen for $1/kg

• JoBo@feddit.uk ⁨1⁩ ⁨year⁩ ago

  Green hydrogen has a lot of advantages for cars compared to batteries: quick refuelling, much less weight, better range. Compared to CO2 emitting fuels (including non-green hydrogen), no contest.

  It’s especially good for heavy vehicles. It’s the only way we can currently use non-carbon fuels for air travel. It’s much more feasible for trucking than batteries.

  Green hydrogen is more like a kind of battery than a fuel. It’s a good way to store renewable energy that cannot be used immediately, or that needs to be used off-grid. How hydrogen is transforming these tiny Scottish islands

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  • greengnu@slrpnk.net ⁨1⁩ ⁨year⁩ ago

    quick refueling only matters if your travel distance exceeds your battery’s range (which for 95% of driving is less than 100 miles) I would agree on the weight issue only if you don’t engineer the hydrogen storage to properly survive car crashes. Range is of no practical use if it vastly exceeds your needs.

    I find trains better for heavy transport and fixed route power lines would cover that problem in a more efficient manner.

    Hydrogen would take double conversion loses if used like a battery and a flywheel would be more efficient at storing renewable energy at a grid level.

    Off-grid energy storage can be done in heavy weight battery chemistries which can last forever without the maintenance cost that must occur with combustion. (heck even Nickel–iron batteries from 1901 would work)

    I will grant you that hydrogen has many useful and wonderful applications.

    Home energy storage and transportation are not one of them.

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    • JoBo@feddit.uk ⁨1⁩ ⁨year⁩ ago

      quick refueling only matters if your travel distance exceeds your battery’s range (which for 95% of driving is less than 100 miles)

      This is such a non-argument. I cannot have one car for short distances and another one for road trips.

      There are no electric cars that can get me to my Dad’s and back without recharging. He does at least have off-road parking but he doesn’t have a safe charging point. I don’t have off-road parking so charging at home is not possible. Yes, I can pay over the odds to charge while I do my supermarket shop, but I wouldn’t usually use my car for the supermarket shop and I don’t want to use my car for the supermarket shop. The only option for long journeys is to take an annoyingly long break.

      Hydrogen is very inefficient, for sure. But there’s no other way to get an electric plane that can replace existing passenger aircraft. Batteries are a non-starter for heavy transport because they’re too big and too heavy to be practical. That’s why we’ve been rolling out hydrogen buses for a couple of years now.](www.greencarfuture.com/…/how-hydrogen-buses-work)

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      • greengnu@slrpnk.net ⁨1⁩ ⁨year⁩ ago

        completely fair perspective, if you are required to travel large distances outside of cities then liquid fuels would be the superior option.

        But if cities are linked by high speed rail and effective bus coverage; there would be no need for a car to visit someone. #fuckcars

        I do agree that batteries are not a good solution for planes but I believe plane use should be only for special cases that are extremely time sensitive (like organ transplant transportation) and are of high social benefit (which could justify carbon fuel usage)

        One doesn’t need batteries or combustion in heavy transport as fixed lines can just use electric wires which saves on moving weight and would make such transport more efficient that any carried fuel source.

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      • schroedingershat@lemmy.world ⁨1⁩ ⁨year⁩ ago

        You’re trying to argue that 10-15 minutes of reliable delay on a road trip over 500km trumps hours over the rest of the year filling (and also a probably 20 minutes of delay because hydrogen filling stations slow way down and only give half a tank during heavy use).

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  • schroedingershat@lemmy.world ⁨1⁩ ⁨year⁩ ago

    FCEVs are a scam. The mirai is heavier than BEVs with similar range, bulkier, and has a much smaller internal volume. BEV busses are volume limited not weight limited and are already capable of covering most routes with only overnight charging (so hydrogen is worse there). Fuelling time in real world situations favours the vehicle that is sitting at 80-100% full every morning over the one you have to visit a fuelling station for. Heavy trucking is cost limited, not time limited – so filling the trucj with the cheap electricity directly at 4x efficiency is better even in the low production season.

    It’s also not “the only way” for air travel because there are no planes that use it, volume constraints limit use cases to those that mostly overlap with batteries (and don’t replace liquid fuels) and battery aircraft are much closer to production (albeit limited in niche so far).

    Every single use case of hydrogen has better alternatives.

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    • JoBo@feddit.uk ⁨1⁩ ⁨year⁩ ago

      It’s very hard to work out how much you know and how much you are making up.

      World’s first hydrogen-powered commercial aircraft takes to the skies above Bedfordshire

      Fuelling time in real world situations favours the vehicle that is sitting at 80-100% full every morning over the one you have to visit a fuelling station for.

      Not unless the batteries have enough capacity to last all day. And hydrogen refuelling stations are being built at bus depots because obviously they are. Do you imagine carbon-fuel busses head to their local filling station when they run low?

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      • schroedingershat@lemmy.world ⁨1⁩ ⁨year⁩ ago

        en.m.wikipedia.org/wiki/ZeroAvia

        They tested a small aircraft for a few minutes at a time before crashing it and it’s nowhere near production.

        Not unless the batteries have enough capacity to last all day. And hydrogen refuelling stations are being built at bus depots because obviously they are. Do you imagine carbon-fuel busses head to their local filling station when they run low?

        Then you’re adding a redundant $5-10million high capacity filling station to the depot cost on top of the other costs. Also you need more depots because hydrogen busses (at least the ones that don’t get at least half their energy from a battery) have lower range than the top end battery busses.

        As I said before. Op charging and pantographs are being abandoned already because overnight charging is more than sufficient. 0.7-1kWh per km is perfectly doable and 500kWh batteries even without current gen LMFP (which reduces weight by 30% vs lfp in use now) has no impact on payload, any route that isn’t non-stop can run all day with just a single charge during lunch breK. 1000kWh raises the floor or reduces clearance (but still less than hydrogen) and the bus will run for longer than a driver can legally.

        Realistically most batteries are in the 250-350kWh range because more is unnecessary.

        The only people still pushing hydrogen busses are platinum miners or oil and gas shills.

        Heavy trucking is less absurd, but they can already drive for the maximum 11 hours in a 13 hour shift so there is little benefit.

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• oldGregg@lemm.ee ⁨1⁩ ⁨year⁩ ago

  You wouldn’t want the water to hydrogen plant inside the car but a hydrogen powered car would operate fine

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  • greengnu@slrpnk.net ⁨1⁩ ⁨year⁩ ago

    You forgot to read the section on hydrogen storage, infrastructure and safety problems.

    But I guess you are correct that we are from an engineering perspective able to make hydrogen powered cars but I would argue that it combustion is not a good solution to transportation when proper infrastructure would be able to do without those risks.

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  • schroedingershat@lemmy.world ⁨1⁩ ⁨year⁩ ago

    Sure if you want a range of <150km and to need a complete teardown and engineer-certified replacement of the fuelling system every 5 years for safety.

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