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One alternative idea I've been thinking about is immediately convert all renewable energy into hydrogen gas. Then the hydrogen is piped to where it's need, or s

by Hypx 6y ago

One alternative idea I've been thinking about is immediately convert all renewable energy into hydrogen gas. Then the hydrogen is piped to where it's need, or stored in underground caverns for later use. Power generation becomes entirely local via fuel cells. Since hydrogen can be stored for long periods of time, the intermittency problem goes away. Although there would be a near-term loss of efficiency, the sheer simplicity of the solution is remarkable. It even eliminates the issue of down power lines cause fires, which is a major issue in California today.

Dig1t 6y ago
I think there are 2 problems: 1. Hydrogen is hard to contain and store cheaply; it's so light it escapes containers easily 2. Hydrogen is kind of explodey
- Hypx 6y ago
  You store hydrogen in underground caverns. This is both simple and very cheap. Hydrogen isn't flammable unless it is mixed with oxygen. That's the same with any other chemical fuel.
voodootrucker 6y ago
If you're curious about more viable energy storage solutions: https://youtu.be/kAB3-lzxvkE?t=277 https://youtu.be/kAB3-lzxvkE?t=277 (hydrogen is covered)
jimmyswimmy 6y ago
Metal hydrides have been proposed as a possible solution. We talked to a small R&D firm years ago that had proposed putting power stations in remote areas where energy is immediately converted into a metal hydride; in their case, magnesium hydride. I remember the process of reforming magnesium hydroxide back was fairly energy intensive, perhaps too much to be considered efficient. The benefit of storing magnesium hydride is it's much easier to store safely in large volumes than hydrogen gas. Hydrogen gas leaks through everything, it's just so small. On the other hand, you have to collect spent material (presumably at "gas stations") and return it to the energy farm, which is more complex than the one-way delivery system you'd have with hydrogen. Still seemed like an interesting idea.
- Hypx 6y ago
  You can buy a metal hydride storage system next year: https://www.bloomberg.com/news/articles/2020-10-19/tesla-powerwall-rival-seeks-to-bring-hydrogen-into-your-home https://www.bloomberg.com/news/articles/2020-10-19/tesla-pow...
epistasis 6y ago
This is far more complicated than using the electricity directly, at time of generations, when possible. The most clear headed, short form, explanation of hydrogen's potential I've seen is here: https://about.bnef.com/blog/liebreich-separating-hype-from-hydrogen-part-two-the-demand-side/ https://about.bnef.com/blog/liebreich-separating-hype-from-h... We will likely end up using hydrogen in three situations: chemical feedstocks, some industrial heat processes that may want some reduction too, and backup grid generation. Switching pipelines to hydrogen has huge, unsolved problems. The energy density is far lower, meaning that even with current demand, natural gas pipelines repurposed to hydrogen would be inadequate. Already, building new pipelines for NG is so difficult that LNG storage is deployed to relieve congestion. Hydrogen would make that far worse. And there are many small things, like making the pipelines robust to the damaging effects of hydrogen, and even coming up with some sort of odorant like the mercapten in natural gas; we don't have any chemicals that can work at the moment. There is a lot of appeal to hydrogen, and with a decade of intense industrial development we may be able to make carbon-free electrolysis derived hydrogen economical for many use cases. But it won't be many, IMHO.
- Hypx 6y ago
  The article you cited is just a person trying to, from purely an a priori standpoint, determine what is possible based on how things currently are. At no point does he try to imagine where the technology will be or where society will be in 10-30 years time. The most damning parts are where he predicts that hydrogen will fail to hit its cost targets even decades from now. That's completely in opposition to nearly every other green energy program tried recently, and I think reveals his lack of foresight. I think the only valid point he made is that electricity is more efficient in a lot of circumstances. But we already knew that, and in fact it's arguably not worth pursuing in a world that will be soon awashed in green energy. Plus, all of the other problems unrelated to efficiency look devastatingly hard if our goal is to have a pure zero emissions world. Ultimately, it's exactly what Arthur Clarke warned us about regarding old people making predictions. So no, this not a "clear headed" analysis but arguably a document of luddite thinking. > Switching pipelines to hydrogen has huge, unsolved problems. The energy density is far lower, meaning that even with current demand, natural gas pipelines repurposed to hydrogen would be inadequate. Already, building new pipelines for NG is so difficult that LNG storage is deployed to relieve congestion. Hydrogen would make that far worse. And there are many small things, like making the pipelines robust to the damaging effects of hydrogen, and even coming up with some sort of odorant like the mercapten in natural gas; we don't have any chemicals that can work at the moment. We've been piping hydrogen for decades, so this is mostly a solved problem: https://en.wikipedia.org/wiki/Hydrogen_pipeline_transport https://en.wikipedia.org/wiki/Hydrogen_pipeline_transport Hydrogen will only mean larger tanks and bigger pipes compared to natural gas. This is a vast improvement over batteries or other physically based energy storage, which are dozens to hundreds of times less energy dense. You can easily figure out that the latter cases would be truly enormous in comparison, not to mention needing something much more complicated than just underground caverns. Furthermore, there's no practical way of moving electricity across oceans. I mean yes, you can build HVDC underwater and that works to some extent, but it quickly becomes ridiculously expensive if you try to connect distant landmasses in a giant web of connected grids. With hydrogen, you are looking at shipping hydrogen like LNG. At a basic level, you're looking at a grid that works just like the existing one, only much cleaner and slightly more expensive. Only difference this time you can put the fuel cells very close to the end-customer since there are no CO2 or NOx emissions. This nearly eliminates the need for giant overhead powerlines, itself a major benefit. Compared to the vast complexity of what we're seeing with the "macrogrid" this looks very doable.

by Hypx 6y ago

Dig1t 6y ago

I think there are 2 problems: 1. Hydrogen is hard to contain and store cheaply; it's so light it escapes containers easily 2. Hydrogen is kind of explodey

Hypx 6y ago
You store hydrogen in underground caverns. This is both simple and very cheap. Hydrogen isn't flammable unless it is mixed with oxygen. That's the same with any other chemical fuel.

voodootrucker 6y ago

If you're curious about more viable energy storage solutions: https://youtu.be/kAB3-lzxvkE?t=277 https://youtu.be/kAB3-lzxvkE?t=277 (hydrogen is covered)

jimmyswimmy 6y ago

Metal hydrides have been proposed as a possible solution. We talked to a small R&D firm years ago that had proposed putting power stations in remote areas where energy is immediately converted into a metal hydride; in their case, magnesium hydride. I remember the process of reforming magnesium hydroxide back was fairly energy intensive, perhaps too much to be considered efficient. The benefit of storing magnesium hydride is it's much easier to store safely in large volumes than hydrogen gas. Hydrogen gas leaks through everything, it's just so small. On the other hand, you have to collect spent material (presumably at "gas stations") and return it to the energy farm, which is more complex than the one-way delivery system you'd have with hydrogen. Still seemed like an interesting idea.

Hypx 6y ago
You can buy a metal hydride storage system next year: https://www.bloomberg.com/news/articles/2020-10-19/tesla-powerwall-rival-seeks-to-bring-hydrogen-into-your-home https://www.bloomberg.com/news/articles/2020-10-19/tesla-pow...

epistasis 6y ago

This is far more complicated than using the electricity directly, at time of generations, when possible. The most clear headed, short form, explanation of hydrogen's potential I've seen is here: https://about.bnef.com/blog/liebreich-separating-hype-from-hydrogen-part-two-the-demand-side/ https://about.bnef.com/blog/liebreich-separating-hype-from-h... We will likely end up using hydrogen in three situations: chemical feedstocks, some industrial heat processes that may want some reduction too, and backup grid generation. Switching pipelines to hydrogen has huge, unsolved problems. The energy density is far lower, meaning that even with current demand, natural gas pipelines repurposed to hydrogen would be inadequate. Already, building new pipelines for NG is so difficult that LNG storage is deployed to relieve congestion. Hydrogen would make that far worse. And there are many small things, like making the pipelines robust to the damaging effects of hydrogen, and even coming up with some sort of odorant like the mercapten in natural gas; we don't have any chemicals that can work at the moment. There is a lot of appeal to hydrogen, and with a decade of intense industrial development we may be able to make carbon-free electrolysis derived hydrogen economical for many use cases. But it won't be many, IMHO.

Hypx 6y ago
The article you cited is just a person trying to, from purely an a priori standpoint, determine what is possible based on how things currently are. At no point does he try to imagine where the technology will be or where society will be in 10-30 years time. The most damning parts are where he predicts that hydrogen will fail to hit its cost targets even decades from now. That's completely in opposition to nearly every other green energy program tried recently, and I think reveals his lack of foresight. I think the only valid point he made is that electricity is more efficient in a lot of circumstances. But we already knew that, and in fact it's arguably not worth pursuing in a world that will be soon awashed in green energy. Plus, all of the other problems unrelated to efficiency look devastatingly hard if our goal is to have a pure zero emissions world. Ultimately, it's exactly what Arthur Clarke warned us about regarding old people making predictions. So no, this not a "clear headed" analysis but arguably a document of luddite thinking. > Switching pipelines to hydrogen has huge, unsolved problems. The energy density is far lower, meaning that even with current demand, natural gas pipelines repurposed to hydrogen would be inadequate. Already, building new pipelines for NG is so difficult that LNG storage is deployed to relieve congestion. Hydrogen would make that far worse. And there are many small things, like making the pipelines robust to the damaging effects of hydrogen, and even coming up with some sort of odorant like the mercapten in natural gas; we don't have any chemicals that can work at the moment. We've been piping hydrogen for decades, so this is mostly a solved problem: https://en.wikipedia.org/wiki/Hydrogen_pipeline_transport https://en.wikipedia.org/wiki/Hydrogen_pipeline_transport Hydrogen will only mean larger tanks and bigger pipes compared to natural gas. This is a vast improvement over batteries or other physically based energy storage, which are dozens to hundreds of times less energy dense. You can easily figure out that the latter cases would be truly enormous in comparison, not to mention needing something much more complicated than just underground caverns. Furthermore, there's no practical way of moving electricity across oceans. I mean yes, you can build HVDC underwater and that works to some extent, but it quickly becomes ridiculously expensive if you try to connect distant landmasses in a giant web of connected grids. With hydrogen, you are looking at shipping hydrogen like LNG. At a basic level, you're looking at a grid that works just like the existing one, only much cleaner and slightly more expensive. Only difference this time you can put the fuel cells very close to the end-customer since there are no CO2 or NOx emissions. This nearly eliminates the need for giant overhead powerlines, itself a major benefit. Compared to the vast complexity of what we're seeing with the "macrogrid" this looks very doable.