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Electrolytic hydrogen production scales poorly. Cost aside, the additional electricity required to replace methane-derived hydrogen is completely infeasible for

Electrolytic hydrogen production scales poorly. Cost aside, the additional electricity required to replace methane-derived hydrogen is completely infeasible for the foreseeable future. Just because we can produce almost any chemistry with electricity does not imply that we have remotely enough spare power generation capacity to make it feasible. Too many proposals for green industrial chemistry implicitly assume that we have several terawatts of green power generation just lying around, which is manifestly not the case nor are we likely to have that kind of extra capacity on any timeframe that matters.

erhk 5y ago
Power grids regularly go negative couldn't there be money made from chemical production on hot and windy days
- Scoundreller 5y ago
  For some unknown reason, transmission/distribution pricing is often fixed, even though peak users are directly culpable for the costs of upgrades.
yxhuvud 5y ago
I'm not certain that is actually correct. The biggest steel maker here in Sweden is in early stages of replacing coal with hydrogen in their new production chains they are building, based on wind power. The really good part is that it is a consumption of electricity that is pretty resilient against varying production volumes, which make it pretty ideal for renewables. The same logic could very well work with fertilizer.
- Robotbeat 5y ago
  Of course it’s not correct. I have no idea why people speak so confidently about electrolysis not being “scalable” when, in fact, that used to be pretty much the primary way of making hydrogen for ammonia. Also, the US used to double electricity generation every decade. If something needs a bit more electricity, there’s no “scaling” argument why we can’t just produce more electricity. It costs money, of course, but there’s no part of it that isn’t “scalable.”
  - jandrewrogers 5y ago
    The amount of electricity required to generate an equivalent amount of hydrogen for ammonia production by electrolysis is 1.5-2 PWh annually. That significantly exceeds all wind power generation globally, even assuming we could dedicate it entirely to making ammonia, which of course we can't because we need to keep the lights on. I also don't think you understand what it means to run an industrial plant at that scale or the logistics (pipelines and such) implied, particularly when the power source is so diffuse. You keep using the words "scalability" but it isn't clear you understand what that actually means in this context. If you are interested in this stuff, perhaps you should study chemical engineering. The feasibility issues will be more intuitive.
    - Hypx_ 5y ago
      2 PWh is not really a challenge other than scaling it up. We have many orders of magnitude more wind and solar energy that the world needs. Water won't run out either, especially when you realize that salt water can be used for this process.
- jandrewrogers 5y ago
  I don't think you are understanding the differences in scale. Ammonia is produced in truly massive quantities, it is one of the highest volume industrial chemicals produced. It is transported around the world in pipelines. The amount of hydrogen used to make steel is a rounding error by comparison. Making hydrogen via electrolysis requires 50 MWh per ton. Manufacturing ammonia requires tens of millions of tons of hydrogen every year.
  - Robotbeat 5y ago
    Right, about 40 megatons of hydrogen to produce all the nitrogen fertilizer. About 270GW average electrical power (67% HHV efficient hydrogen electrolysis, not counting liquefaction or compression). BUT ammonia is a global commodity that can be and is distributed all over the world, so that means you can produce it wherever clean energy is cheapest. Chile has excellent wind AND excellent solar (best in the world), meaning you can operate electrolysis at higher capacity factor, and it has sea ports. So there are plans for big green ammonia projects being built there. https://renewablesnow.com/news/engie-enaex-plan-green-hydrogen-to-ammonia-projects-in-chile-751727/ https://renewablesnow.com/news/engie-enaex-plan-green-hydrog... But it can also just provide food security by being a local source of fertilizer that is independent of global logistical constraints or fluctuations in availability of natural gas. It’s also potentially an alternative mechanism for hydrogen storage. Some ships already run on ammonia, and you can run tractors (etc) on it as well without the extreme challenges in storage that compressed or liquid hydrogen have (its somewhere between LNG and propane when it comes to storage difficulty). However, it’s probably not a great consumer fuel due to toxicity.
ben_w 5y ago
Does it scale poorly for any reason other than current availability of electricity? The growth of PV has been pretty close to exponential since ‘92, with the current (nameplate) capacity estimated to be just short of 1 terawatt and a doubling time of 2.2 years, so I think we will have a few terawatts on a relevant timescale.
- Robotbeat 5y ago
  It actually scales extremely well. Based on DoE studies I’ve read, Hydrogen electrolysis systems that are larger tend to have lower specific capital costs and usually operate at higher efficiency than smaller plants. We also used to double electricity production every decade before demand for electricity plateaued. Sometimes people just say things on the Internet that are wrong.
johnrgrace 5y ago
Turn off bitcoin does that provide enough power so the world doesn't starve?
- lachstar-x 5y ago
  No
  - Robotbeat 5y ago
    More specifically, Bitcoin consumes about 10GW average. To make all nitrogen fertilizer with electrolytes hydrogen would require about 270GW average. It’s nowhere close.

erhk 5y ago

Power grids regularly go negative couldn't there be money made from chemical production on hot and windy days

Scoundreller 5y ago
For some unknown reason, transmission/distribution pricing is often fixed, even though peak users are directly culpable for the costs of upgrades.

yxhuvud 5y ago

I'm not certain that is actually correct. The biggest steel maker here in Sweden is in early stages of replacing coal with hydrogen in their new production chains they are building, based on wind power. The really good part is that it is a consumption of electricity that is pretty resilient against varying production volumes, which make it pretty ideal for renewables. The same logic could very well work with fertilizer.

Robotbeat 5y ago
Of course it’s not correct. I have no idea why people speak so confidently about electrolysis not being “scalable” when, in fact, that used to be pretty much the primary way of making hydrogen for ammonia. Also, the US used to double electricity generation every decade. If something needs a bit more electricity, there’s no “scaling” argument why we can’t just produce more electricity. It costs money, of course, but there’s no part of it that isn’t “scalable.”
- jandrewrogers 5y ago
  The amount of electricity required to generate an equivalent amount of hydrogen for ammonia production by electrolysis is 1.5-2 PWh annually. That significantly exceeds all wind power generation globally, even assuming we could dedicate it entirely to making ammonia, which of course we can't because we need to keep the lights on. I also don't think you understand what it means to run an industrial plant at that scale or the logistics (pipelines and such) implied, particularly when the power source is so diffuse. You keep using the words "scalability" but it isn't clear you understand what that actually means in this context. If you are interested in this stuff, perhaps you should study chemical engineering. The feasibility issues will be more intuitive.
  - Hypx_ 5y ago
    2 PWh is not really a challenge other than scaling it up. We have many orders of magnitude more wind and solar energy that the world needs. Water won't run out either, especially when you realize that salt water can be used for this process.
jandrewrogers 5y ago
I don't think you are understanding the differences in scale. Ammonia is produced in truly massive quantities, it is one of the highest volume industrial chemicals produced. It is transported around the world in pipelines. The amount of hydrogen used to make steel is a rounding error by comparison. Making hydrogen via electrolysis requires 50 MWh per ton. Manufacturing ammonia requires tens of millions of tons of hydrogen every year.
- Robotbeat 5y ago
  Right, about 40 megatons of hydrogen to produce all the nitrogen fertilizer. About 270GW average electrical power (67% HHV efficient hydrogen electrolysis, not counting liquefaction or compression). BUT ammonia is a global commodity that can be and is distributed all over the world, so that means you can produce it wherever clean energy is cheapest. Chile has excellent wind AND excellent solar (best in the world), meaning you can operate electrolysis at higher capacity factor, and it has sea ports. So there are plans for big green ammonia projects being built there. https://renewablesnow.com/news/engie-enaex-plan-green-hydrogen-to-ammonia-projects-in-chile-751727/ https://renewablesnow.com/news/engie-enaex-plan-green-hydrog... But it can also just provide food security by being a local source of fertilizer that is independent of global logistical constraints or fluctuations in availability of natural gas. It’s also potentially an alternative mechanism for hydrogen storage. Some ships already run on ammonia, and you can run tractors (etc) on it as well without the extreme challenges in storage that compressed or liquid hydrogen have (its somewhere between LNG and propane when it comes to storage difficulty). However, it’s probably not a great consumer fuel due to toxicity.

ben_w 5y ago

Does it scale poorly for any reason other than current availability of electricity? The growth of PV has been pretty close to exponential since ‘92, with the current (nameplate) capacity estimated to be just short of 1 terawatt and a doubling time of 2.2 years, so I think we will have a few terawatts on a relevant timescale.

Robotbeat 5y ago
It actually scales extremely well. Based on DoE studies I’ve read, Hydrogen electrolysis systems that are larger tend to have lower specific capital costs and usually operate at higher efficiency than smaller plants. We also used to double electricity production every decade before demand for electricity plateaued. Sometimes people just say things on the Internet that are wrong.

johnrgrace 5y ago

Turn off bitcoin does that provide enough power so the world doesn't starve?

lachstar-x 5y ago
No
- Robotbeat 5y ago
  More specifically, Bitcoin consumes about 10GW average. To make all nitrogen fertilizer with electrolytes hydrogen would require about 270GW average. It’s nowhere close.