12 ms·

Having a "serious interest" and earnestly wanting it this time doesn't change the fundamental fact that you need a lot of power to crack water apart. There's

Having a "serious interest" and earnestly wanting it this time doesn't change the fundamental fact that you need a lot of power to crack water apart. There's simply no way around that, all improvements found will be marginal at best.

DesiLurker 4y ago
I wish somebody would do a very simple roundtrip calculation for each of these 'breakthroughs' and publish it. all i want to know is the efficiency, cost & power density these on consumption side so I can decide which applications this works best in. on the production side same thing except for power density. the fact that its incredibly hard to find these numbers makes me think that these are mostly puff pieces for hydrogen before BEV eats their lunch. green/blue/gray hydrogen is mostly BS.
- PaulHoule 4y ago
  The main interest now is not for ‘dispatchable energy’ but for industrial uses of hydrogen, metallurgy, etc. There is a lot of competition for energy storage such as conventional batteries, vanadium flow batteries, compressed air, pumped hydro, etc. I think fuel cell cars have been dead since Tesla made attractive BEV cars.
  - DesiLurker 4y ago
    why would I care about hydrogen when I have a perfectly good electrical system ready in hand. hydrogen's main selling point is energy density, which makes is good on paper for 'mobile' applications. if you forgo that than there are plenty of good energy carries like NG/gasoline or electricity which round-trip much better in efficiency terms. I am not sure if there is a sudden step up in industrial uses of H. on face value this looks more like groundwork for some upcoming fossil greenwashing subsidy that uses hydrogen to justify public funds.
    - MichaelCollins 4y ago
      I'm not sure you understood this: "The main interest now is not for ‘dispatchable energy’ but for industrial uses of hydrogen, metallurgy, etc." He's not talking about hydrogen as a store of energy. He's talking about hydrogen to be used in industrial processes that require hydrogen input. Energy density has nothing to do with it, and the superiority of NG/gas/electic for carrying energy isn't relevant. > I am not sure if there is a sudden step up in industrial uses of H Step up? There is existing demand for hydrogen which this would, presumably, be more efficient at meeting. If they're not meeting that demand for hydrogen by cracking water apart, they'll do it by cracking natural gas apart instead.
- somewhat_drunk 4y ago
  Look up Paul Martin on linkedin for a thorough examination of H2 as a fuel, including round-trip efficiency.
  - DesiLurker 4y ago
    thanks for the suggestion. This is exactly what I needed: https://www.linkedin.com/pulse/distilled-thoughts-hydrogen-paul-martin/ https://www.linkedin.com/pulse/distilled-thoughts-hydrogen-p... esp the efficiency chart about 1/3rd way in lays it bare.
    - somewhat_drunk 4y ago
      You're welcome!
- Animats 4y ago
  > I wish somebody would do a very simple roundtrip calculation for each of these 'breakthroughs' and publish it. Yeah. Commercial electrolyzers are about 70% efficient right now. So only 30% headroom is available for improvement. There are people with prototypes that claim 95%. It's apparently possible to beat 70% without much trouble, but overall costs go up. If you search for "electrolyzer efficiency" you find discussions of equipment size, cost, durability, water quality requirements, and purity of the output gases. That's apparently a bigger issue in practice than electrical efficiency. The breakthrough story industry wants is "we built a big one, it cost half as much to build, it runs on tap water, and it's self-cleaning." When you electrolyze water, the dissolved solids have to come out somewhere. Or you have to start with highly purified water, which means a big water processing operation and more operating cost.
pencilguin 4y ago
The amount of energy to crack water is already only a small multiple of what you get back when you get the products back together. The improvements are in the cost of equipment per unit output capacity, and the production rate per unit volume of said equipment. Improvements are cumulative. Airports, steel mills, and ammonia synthesizers will need to produce huge amounts of H2, soon, so reductions are important.

DesiLurker 4y ago

I wish somebody would do a very simple roundtrip calculation for each of these 'breakthroughs' and publish it. all i want to know is the efficiency, cost & power density these on consumption side so I can decide which applications this works best in. on the production side same thing except for power density. the fact that its incredibly hard to find these numbers makes me think that these are mostly puff pieces for hydrogen before BEV eats their lunch. green/blue/gray hydrogen is mostly BS.

PaulHoule 4y ago
The main interest now is not for ‘dispatchable energy’ but for industrial uses of hydrogen, metallurgy, etc. There is a lot of competition for energy storage such as conventional batteries, vanadium flow batteries, compressed air, pumped hydro, etc. I think fuel cell cars have been dead since Tesla made attractive BEV cars.
- DesiLurker 4y ago
  why would I care about hydrogen when I have a perfectly good electrical system ready in hand. hydrogen's main selling point is energy density, which makes is good on paper for 'mobile' applications. if you forgo that than there are plenty of good energy carries like NG/gasoline or electricity which round-trip much better in efficiency terms. I am not sure if there is a sudden step up in industrial uses of H. on face value this looks more like groundwork for some upcoming fossil greenwashing subsidy that uses hydrogen to justify public funds.
  - MichaelCollins 4y ago
    I'm not sure you understood this: "The main interest now is not for ‘dispatchable energy’ but for industrial uses of hydrogen, metallurgy, etc." He's not talking about hydrogen as a store of energy. He's talking about hydrogen to be used in industrial processes that require hydrogen input. Energy density has nothing to do with it, and the superiority of NG/gas/electic for carrying energy isn't relevant. > I am not sure if there is a sudden step up in industrial uses of H Step up? There is existing demand for hydrogen which this would, presumably, be more efficient at meeting. If they're not meeting that demand for hydrogen by cracking water apart, they'll do it by cracking natural gas apart instead.
somewhat_drunk 4y ago
Look up Paul Martin on linkedin for a thorough examination of H2 as a fuel, including round-trip efficiency.
- DesiLurker 4y ago
  thanks for the suggestion. This is exactly what I needed: https://www.linkedin.com/pulse/distilled-thoughts-hydrogen-paul-martin/ https://www.linkedin.com/pulse/distilled-thoughts-hydrogen-p... esp the efficiency chart about 1/3rd way in lays it bare.
  - somewhat_drunk 4y ago
    You're welcome!
Animats 4y ago
> I wish somebody would do a very simple roundtrip calculation for each of these 'breakthroughs' and publish it. Yeah. Commercial electrolyzers are about 70% efficient right now. So only 30% headroom is available for improvement. There are people with prototypes that claim 95%. It's apparently possible to beat 70% without much trouble, but overall costs go up. If you search for "electrolyzer efficiency" you find discussions of equipment size, cost, durability, water quality requirements, and purity of the output gases. That's apparently a bigger issue in practice than electrical efficiency. The breakthrough story industry wants is "we built a big one, it cost half as much to build, it runs on tap water, and it's self-cleaning." When you electrolyze water, the dissolved solids have to come out somewhere. Or you have to start with highly purified water, which means a big water processing operation and more operating cost.

pencilguin 4y ago

The amount of energy to crack water is already only a small multiple of what you get back when you get the products back together. The improvements are in the cost of equipment per unit output capacity, and the production rate per unit volume of said equipment. Improvements are cumulative. Airports, steel mills, and ammonia synthesizers will need to produce huge amounts of H2, soon, so reductions are important.