4 ms·

The answer is 2). It is inherently cheaper to make a low energy, high carbon, biofuel than it is to make a high energy fuel that can actually be used. And it

by btilly 4y ago

The answer is 2). It is inherently cheaper to make a low energy, high carbon, biofuel than it is to make a high energy fuel that can actually be used. And it is cheaper exactly by the energy you don't have to leave in the fuel. Furthermore for many applications, electrical+batteries is more efficient than fossil fuels. So with projected near-term technologies, it makes no sense to make a round trip through fossil fuels.

Schroedingersat 4y ago
Nice shell game there. Double counting costs and hiding the externalities of the fossil fuels. Take a state of the art green hydrogen system at about $4/kg (and falling rapidly with projections as low a $1 in a decade) Let's assume we have a machine that can sequester 80mJ worth of CO2 from fossil fuels or about 0.75kg of carbon or 200g of CO2 from the air for $1 If the cost of extracting, refining, storing, transporting and dispensing 80mJ of fossil fuels ever exceeds $3 (or the cost of the green hydrogen goes down equivalently) you've lost instantly. But it's much worse than that, because that 80mJ of fossil fuel required about 160mJ of fossil fuel to be burnt durng extracting, refining, storing, transporting and dispensing, so now you have to get it for $1 (less than the current market price of methane). You could argue that you can use green energy for all of the steps to get the fossil fuel, but that's just an incredibly stupid, expensive, polluting and roundabout way of makng a water electrolyzer. Locally made Hydrogen becoming a more economical fuel than fossil fuels by 2035 is an inevitability. The only relevant question is whether we can find a cheap and efficient way of storing it or turning it into something at least as heavy as methane or ammonia. Batteries will always be better per joule dispensed and thus for daily or even weekly fluctuations, but a year of capacity is unsolved and chemical storage has some pretty big upsides.
- ncmncm 4y ago
  "A year of capacity" is just a big tank of ammonia. Not that anybody needs that, because tanks of ammonia are transportable from places that produce reliably.
  - Schroedingersat 4y ago
    If you're smoothing out long term trends then on the order of a year is the important bit to keep the "but I liiiive in the aarctic and have no insulation and cannot conceive of the concept of a thermal battery" crowd from derailing things. It doesn't really matter where it's stored, but you need to be able to make it cost effectively. More seriously countries in high latitudes need a winter's worth as a strategic reserve to avoid being left in the situation much of europe is in now. Ammonia is unfortunately not yet provably viable on a cost basis, but it's probably the most likely of the top three contenders; the others being, methane, and metal hydride.
    - ncmncm 4y ago
      Metal hydride is out. Methane needs a carbon source. A lot of real capital is betting now on hydrogen (mainly stationary) and ammonia (mobile).
      - Schroedingersat 4y ago
        I think the end result might be a mix. Methane is much safer, has existing infrastructure and appliances, works in petrol cars with minor change, and seems to require less extreme conditions and complex plant so may be a viable way to take advantage of carbon sources at smaller scales. Metal hydride seems like the only potential household scale electricity->fuel->electricity option (not that that's a necessity or even overly efficient, but an affordable complete standalone system would close the book on fossil fuels and finally end the nuclear shilling) as fuel cells, solar power, and electrolyzers can already be had for a combined price of well under electricity retail. It is also safer than ammonia (at least the heavily endothermic versions are). What makes you dismiss it entirely as a research avenue (other than being far too expensive at present)?
        ncmncm 4y ago
        Batteries typically can do as much wattage in and out as you are likely to want, but 2x storage is 2x cost. Metal hydrides can store as much hydrogen as you have bought pricy porous metal. In that way it is much like a battery, with the added complication of the fuel cell and electrolyser limiting discharge and charge rate. I.e., want more watts in, buy more electrolyser, more out buy more fuel cell, more storage more pricy metal. The appeal of liquid fuels of various sorts is that tankage is cheap. Want more storage, buy more tank. Tank empty, call for a truck to fill it. When your tankage is full, you can fill somebody else's, and call them up to haul away when full, and pay you. They won't want to leave expensive metal or batteries with you to be charged up when you feel like it. But leaving empty tanks around is an easy choice.
- ephbit 4y ago
  > ... The only relevant question is whether we can find a cheap and efficient way of storing it ... Not sure which percentage of the cost of the whole system comes from the hydrogen storage in these standardized steel containers. To me it looks like the bigger issue for most property owners would be finding the space for putting enough of these containers (guess they need to be kept outdoors for security reasons) rather than the cost of the containers themselves. https://www.homepowersolutions.de/en/product/ https://www.homepowersolutions.de/en/product/
  - Schroedingersat 4y ago
    Per residence storage is likely going to be fairly niche and much more expensive unless you're using the heat in both directions. Crompressed hydrogen is way too big and dangerous, cryo is unfeasible and far too dangerous for small scale and expensive at large, and metal hydride storage is still too expensive to put mined methane to bed. Ammonia (as the other commenter mentioned) is a major contender, but I expect it will be blocked soon for small scale by the methane lobby with the rationalization of "der terrerrists haev nitrogen'. Synthetic methane is the other major contender.
    - ephbit 4y ago
      > Crompressed hydrogen is way too big and dangerous .. The linked company appears to be able to handle this. Although there aren't that many installations of their system. (Which is probably due to the system not yet reaching break even soon if at all, because energy is still quite cheap.) As soon as an ammonia fuel cell is available as mature tech, ammonia will probably be the storage of choice for large scale systems. But for residential storage hydrogen has the advantage that an electrolyser is comparatively simple mature tech, while ammonia synthesis probably won't be soon if ever.
      - Schroedingersat 4y ago
        I can't find any price or performance numbers on their site so I'm sceptical. I did find some alibaba listings for pressure tanks. The cheapest believable ones were about $100 for a 50L 300bar tank. This works out to about $3k for a MWh of storage. You'd have to fill and empty it a couple of times a year for 20 years to break even vs nuclear just on the storage cost. It might beat retail in some areas though, and you'd need 50 or so of them to over winter in cold areas. Sounds like medium term storage (weeks) is solved if $100/tank (or even $1000/tank) is doable though.
ZeroGravitas 4y ago
To be more exact: If the goal is to remove fossil CO2 that is already in the air, then this process is doing more than it needs to and so won't compete with just running their system and using the output from the first step as a chemical feedstock instead of using extra energy to turn it into a classic fuel. But, the key missing option is 3) use the electricity you were going to use to make the fuel to do the end task directly and much more efficiently, and without fossil or recycled carbon being involved. Their pitch is a bit like: “Someone else has invented the replicator machine that makes any food you want in Star Trek and our business will use that basically free, essentially limitless food as an input to our bioreactors to make Quorn meat substitutes." Quorn is a good thing now, when meat involves expensive, cruelty, waste, carbon and disease. Once you have near limitless food on tap though, it becomes a very niche product.
- ncmncm 4y ago
  Quorn, by the way, turns my stomach. I could not finish a meal of Quorn without losing it and needing to start over. Fortunately there are now better alternatives, and Quorn can go quietly out of business.
- Schroedingersat 4y ago
  The only thing stopping everything from being solar powered is you may not have a solar panel and sunlight when and where you want to use the energy. Batteries solve this somewhat, but are big, heavy, and expensive. Fuels are small, light, cheap to store, and inefficient. You're not going to want to store energy for 6 months with batteries even if they hit the $30-60/kWh range. You're not going to want to store energy as fuel for a few days unless you really need to pick it up and move it. Solar derived fuels are nearly competitive with nuclear ($130/MWh with maybe $10-20/MWh to burn it according to this claim https://www.energy.gov/sites/default/files/2021-08/12-proton-ceramics-using-ammonia.pdf https://www.energy.gov/sites/default/files/2021-08/12-proton... vs $100 for nuclear). Other safer fuels are not far behind for applications closer to people. The energy component of that cost is going to halve or better on a fairly predictable schedule around 2035, so if the cost of the manufacture can be brought down to half or better there's not really any reason to continue with fossil fuels. So the correct metaphor is a replicator that only makes perishable non refrigeratable foods on public holidays. To be able to eat the rest of the time you'll need to make a lot of soup even though you don't really like soup. Also worth noting is this particular project is just buzzword soup that absolutely reeks of a pump and dump scam, and is closely tied to y combinator. Please don't dismiss real e fuel projects when they run off with a few billion dollars of investor money in two years. Edit: found their news article where they break down costs a bit, might not he a scam -- the slicm marketing still reeks of solar roadways though.

by btilly 4y ago

Schroedingersat 4y ago

Nice shell game there. Double counting costs and hiding the externalities of the fossil fuels. Take a state of the art green hydrogen system at about $4/kg (and falling rapidly with projections as low a $1 in a decade) Let's assume we have a machine that can sequester 80mJ worth of CO2 from fossil fuels or about 0.75kg of carbon or 200g of CO2 from the air for $1 If the cost of extracting, refining, storing, transporting and dispensing 80mJ of fossil fuels ever exceeds $3 (or the cost of the green hydrogen goes down equivalently) you've lost instantly. But it's much worse than that, because that 80mJ of fossil fuel required about 160mJ of fossil fuel to be burnt durng extracting, refining, storing, transporting and dispensing, so now you have to get it for $1 (less than the current market price of methane). You could argue that you can use green energy for all of the steps to get the fossil fuel, but that's just an incredibly stupid, expensive, polluting and roundabout way of makng a water electrolyzer. Locally made Hydrogen becoming a more economical fuel than fossil fuels by 2035 is an inevitability. The only relevant question is whether we can find a cheap and efficient way of storing it or turning it into something at least as heavy as methane or ammonia. Batteries will always be better per joule dispensed and thus for daily or even weekly fluctuations, but a year of capacity is unsolved and chemical storage has some pretty big upsides.

ncmncm 4y ago
"A year of capacity" is just a big tank of ammonia. Not that anybody needs that, because tanks of ammonia are transportable from places that produce reliably.
- Schroedingersat 4y ago
  If you're smoothing out long term trends then on the order of a year is the important bit to keep the "but I liiiive in the aarctic and have no insulation and cannot conceive of the concept of a thermal battery" crowd from derailing things. It doesn't really matter where it's stored, but you need to be able to make it cost effectively. More seriously countries in high latitudes need a winter's worth as a strategic reserve to avoid being left in the situation much of europe is in now. Ammonia is unfortunately not yet provably viable on a cost basis, but it's probably the most likely of the top three contenders; the others being, methane, and metal hydride.
  - ncmncm 4y ago
    Metal hydride is out. Methane needs a carbon source. A lot of real capital is betting now on hydrogen (mainly stationary) and ammonia (mobile).
    - Schroedingersat 4y ago
      I think the end result might be a mix. Methane is much safer, has existing infrastructure and appliances, works in petrol cars with minor change, and seems to require less extreme conditions and complex plant so may be a viable way to take advantage of carbon sources at smaller scales. Metal hydride seems like the only potential household scale electricity->fuel->electricity option (not that that's a necessity or even overly efficient, but an affordable complete standalone system would close the book on fossil fuels and finally end the nuclear shilling) as fuel cells, solar power, and electrolyzers can already be had for a combined price of well under electricity retail. It is also safer than ammonia (at least the heavily endothermic versions are). What makes you dismiss it entirely as a research avenue (other than being far too expensive at present)?
      - ncmncm 4y ago
        Batteries typically can do as much wattage in and out as you are likely to want, but 2x storage is 2x cost. Metal hydrides can store as much hydrogen as you have bought pricy porous metal. In that way it is much like a battery, with the added complication of the fuel cell and electrolyser limiting discharge and charge rate. I.e., want more watts in, buy more electrolyser, more out buy more fuel cell, more storage more pricy metal. The appeal of liquid fuels of various sorts is that tankage is cheap. Want more storage, buy more tank. Tank empty, call for a truck to fill it. When your tankage is full, you can fill somebody else's, and call them up to haul away when full, and pay you. They won't want to leave expensive metal or batteries with you to be charged up when you feel like it. But leaving empty tanks around is an easy choice.
ephbit 4y ago
> ... The only relevant question is whether we can find a cheap and efficient way of storing it ... Not sure which percentage of the cost of the whole system comes from the hydrogen storage in these standardized steel containers. To me it looks like the bigger issue for most property owners would be finding the space for putting enough of these containers (guess they need to be kept outdoors for security reasons) rather than the cost of the containers themselves. https://www.homepowersolutions.de/en/product/ https://www.homepowersolutions.de/en/product/
- Schroedingersat 4y ago
  Per residence storage is likely going to be fairly niche and much more expensive unless you're using the heat in both directions. Crompressed hydrogen is way too big and dangerous, cryo is unfeasible and far too dangerous for small scale and expensive at large, and metal hydride storage is still too expensive to put mined methane to bed. Ammonia (as the other commenter mentioned) is a major contender, but I expect it will be blocked soon for small scale by the methane lobby with the rationalization of "der terrerrists haev nitrogen'. Synthetic methane is the other major contender.
  - ephbit 4y ago
    > Crompressed hydrogen is way too big and dangerous .. The linked company appears to be able to handle this. Although there aren't that many installations of their system. (Which is probably due to the system not yet reaching break even soon if at all, because energy is still quite cheap.) As soon as an ammonia fuel cell is available as mature tech, ammonia will probably be the storage of choice for large scale systems. But for residential storage hydrogen has the advantage that an electrolyser is comparatively simple mature tech, while ammonia synthesis probably won't be soon if ever.
    - Schroedingersat 4y ago
      I can't find any price or performance numbers on their site so I'm sceptical. I did find some alibaba listings for pressure tanks. The cheapest believable ones were about $100 for a 50L 300bar tank. This works out to about $3k for a MWh of storage. You'd have to fill and empty it a couple of times a year for 20 years to break even vs nuclear just on the storage cost. It might beat retail in some areas though, and you'd need 50 or so of them to over winter in cold areas. Sounds like medium term storage (weeks) is solved if $100/tank (or even $1000/tank) is doable though.

ZeroGravitas 4y ago

To be more exact: If the goal is to remove fossil CO2 that is already in the air, then this process is doing more than it needs to and so won't compete with just running their system and using the output from the first step as a chemical feedstock instead of using extra energy to turn it into a classic fuel. But, the key missing option is 3) use the electricity you were going to use to make the fuel to do the end task directly and much more efficiently, and without fossil or recycled carbon being involved. Their pitch is a bit like: “Someone else has invented the replicator machine that makes any food you want in Star Trek and our business will use that basically free, essentially limitless food as an input to our bioreactors to make Quorn meat substitutes." Quorn is a good thing now, when meat involves expensive, cruelty, waste, carbon and disease. Once you have near limitless food on tap though, it becomes a very niche product.

ncmncm 4y ago
Quorn, by the way, turns my stomach. I could not finish a meal of Quorn without losing it and needing to start over. Fortunately there are now better alternatives, and Quorn can go quietly out of business.
Schroedingersat 4y ago
The only thing stopping everything from being solar powered is you may not have a solar panel and sunlight when and where you want to use the energy. Batteries solve this somewhat, but are big, heavy, and expensive. Fuels are small, light, cheap to store, and inefficient. You're not going to want to store energy for 6 months with batteries even if they hit the $30-60/kWh range. You're not going to want to store energy as fuel for a few days unless you really need to pick it up and move it. Solar derived fuels are nearly competitive with nuclear ($130/MWh with maybe $10-20/MWh to burn it according to this claim https://www.energy.gov/sites/default/files/2021-08/12-proton-ceramics-using-ammonia.pdf https://www.energy.gov/sites/default/files/2021-08/12-proton... vs $100 for nuclear). Other safer fuels are not far behind for applications closer to people. The energy component of that cost is going to halve or better on a fairly predictable schedule around 2035, so if the cost of the manufacture can be brought down to half or better there's not really any reason to continue with fossil fuels. So the correct metaphor is a replicator that only makes perishable non refrigeratable foods on public holidays. To be able to eat the rest of the time you'll need to make a lot of soup even though you don't really like soup. Also worth noting is this particular project is just buzzword soup that absolutely reeks of a pump and dump scam, and is closely tied to y combinator. Please don't dismiss real e fuel projects when they run off with a few billion dollars of investor money in two years. Edit: found their news article where they break down costs a bit, might not he a scam -- the slicm marketing still reeks of solar roadways though.