6 votes

LAVO hydrogen battery system

5 comments

  1. [4]
    pseudolobster
    (edited )
    Link
    The most interesting thing about this I think is the cycle life. They claim the hydride will last 20,000 cycles, which is really impressive compared to lithium batteries which typically have...

    The most interesting thing about this I think is the cycle life. They claim the hydride will last 20,000 cycles, which is really impressive compared to lithium batteries which typically have lifespans in the low thousands of cycles.

    That said, the cost is pretty crazy, and I'm not sure it makes sense yet. A powerwall 2 is $6500USD, and has 1/3 of the capacity of one of these. Three powerwalls is $19500, versus this thing is $34,750. I'm going to assume those are AUD, so that's nearly $44,000USD (edit) $26,500 USD. Now you might say, this thing is rated for 4x the cycles of the powerwall, and sure that's a great point, but if you're throwing out nearly half of your solar energy due to inefficiencies, you need to buy nearly double the amount of panels and suddenly this isn't making a lot of financial sense.

    1 vote
    1. [3]
      Gyrfalcon
      Link Parent
      I'm not totally sure how you are getting the cost numbers, since I think the AUD is weaker than the USD, so by straight currency conversion it should be about $26,500 USD. Then again, shipping...

      I'm not totally sure how you are getting the cost numbers, since I think the AUD is weaker than the USD, so by straight currency conversion it should be about $26,500 USD. Then again, shipping from Australia (or wherever they are made) as well as any tariffs and other costs would probably bring it up for the US and EU markets. It is also a comparison between a mature, scaled technology against something newer and yet to scale. Their pre order for 2022 onward already drops in price to $29,450 AUD, so that's a plus.

      Pricing aside, what I really don't understand is why they've chosen home energy storage as the strategy here. Based on the sized of those hydrogen packs and the overall size of the unit, it seems like this tech would be purpose made for vehicles, where you can rely on fueling infrastructure to eat the 50% loss and have the electrolyzer, and you just need dense hydrogen storage. Hacking some measurements out of their images, each of those hydrogen storage cells looks to be ~110mm by ~280 mm by ~400 mm and 10 kWh is 36 MJ, so those cells store about 3 MJ per liter volume, which is already better than the best lithium batteries that Wikipedia knows of at 2.43 MJ/L. I wonder if they were worried about how people are always skeeved by hydrogen in vehicles for some reason, or maybe the vast majority of the cost there is tied up in the metal they use for those cells so going bigger looks worse? Either way, I'd love to know their rationale for this application and not automobiles.

      1 vote
      1. pseudolobster
        Link Parent
        There are a few other things I'm suspicious of in terms of longevity. I'm wondering if/how often you need to replace electrodes in the electrolyzer. There's mention of a battery in their block...

        There are a few other things I'm suspicious of in terms of longevity. I'm wondering if/how often you need to replace electrodes in the electrolyzer. There's mention of a battery in their block diagram graphic. It looks like the fuel cell doesn't directly power the electrolyzer, but it uses a dc-dc converter to charge a battery which does so. I've got to wonder, what chemistry is that, and what's its lifespan?

        The datasheet mentions 30 years as the maximum lifespan of the hydrate, whereas one full cycle per day every day for 30 years is 10958 cycles. How is that 20k cycles rating actually meaningful? The warranty is for 10 years. Can we expect this company will exist in 10 years? Can we hope that this company will be successful enough that replacement parts will be available in 10, 20, 30+ years? Otherwise, how repairable is the device, I wonder.

        As for power storage per volume, if you're looking at using hydrogen you might as well use compressed gas. As far as I can tell that's what all the hydrogen cars on the market are doing: https://en.wikipedia.org/wiki/Hydrogen_vehicle

        These hydrate storage things require a chemical reaction to occur where the hydrogen is fixed to metal ions or something. I'm a total layman here, but as far as I understand these reactions don't happen quickly, so there's a limit to how quickly you can charge and discharge them. This 40kWh unit can only output 5kW, which is enough to power an electric clothes dryer and not much else. Certainly not a car. If you were to double these up so you had 80kWh or roughly the same range as a tesla, you'd have 10kW to work with, or 13.4 horsepower. I imagine charging them with hydrogen isn't an instant thing either, and is actually fairly slow, which makes them work okay for solar, but unsuitable for use in a vehicle.

        I'd be less squicky about a hydrate in my car than compressed hydrogen, that's for damn sure. Yet, commercially designed hydrogen cars are on the market, and DIY projects have existed for many decades using compressed gas.

        If anyone wants a rough idea of the reactivity of these sorts of hydrates, here's a good video from mike's electric stuff on youtube: The "Upp" fuel cell charger. A completely pointless product.. At the 47m 20s mark is where he learns the item is full of fire, and at 48m 34s he dumps the whole thing out, where you can see the hydrate being angry that it's being exposed to oxygen. I'd still say it's less spicy than lithium ions in most cases, but in any case I'd be a fair bit more confident rolling around with that than compressed hydrogen.

        Anyway, sorry if I sound overly critical of this. I'd really love for hydrogen to become a viable storage medium, but I've been burned in the past.

        2 votes
      2. pseudolobster
        (edited )
        Link Parent
        Whoops, you're right. I used ddg for currency conversion. I searched for $34750aud and what it gave me was $34750USD in AUD, which is the opposite of what I wanted. Edit: I figured it out. Any...

        Whoops, you're right. I used ddg for currency conversion. I searched for $34750aud and what it gave me was $34750USD in AUD, which is the opposite of what I wanted.

        Edit: I figured it out. Any time you use "$" before the number it assumes USD. If you search for 34750AUD it gives you the result in USD or maybe your local currency, but if you prefix it with $ like "$34750AUD" you get USD-to-whatever.

        1 vote
  2. Gyrfalcon
    Link
    I recently watched this youtube video highlighting the potential of this company's hydrogen storage technology. I think it is an interesting concept despite a lower round trip efficiency compared...

    I recently watched this youtube video highlighting the potential of this company's hydrogen storage technology. I think it is an interesting concept despite a lower round trip efficiency compared to Lithium batteries (~50% vs ~95%). They also appear to be happy to take international pre orders. Do people here think this is a promising technology? Would you consider purchasing one for your own home?