4 ms·

It also assumes a vast hydrogen electric grid storage network - this is only theoretical, nobody has actually deployed a facility that converts electricity to h

It also assumes a vast hydrogen electric grid storage network - this is only theoretical, nobody has actually deployed a facility that converts electricity to hydrogen, and back to electricity. At best this is, "scale up heretofore unproven technologies", not "existing technologies".

pfdietz 3y ago
In the same sense that commercial breeder reactors are theoretical (which is conservative, as you can't actually buy a breeder reactor). But nuclear advocates don't talk about those much, even though they'd be needed for a nuclear powered world.
- Manuel_D 3y ago
  But we don't need commerical breeder reactors. The USA just needs to build 4 PWRs for each reactor it presently has to generate electricity entirely from hydro and nuclear. This is vastly more feasible than provisioning terawatt hours of energy storage. "Just scale up" is a good summary of how to decarbonize through nuclear power. We have decades of experience building nuclear plants. Not so with hydrogen based electricity storage. Plans for renewable grids call for the use of novel electricity storage systems because none of the existing storage mechanisms are feasible. Until we've built the storage mechanisms proposed, any plan involving it's use is effectively hand-waving a big part of its implementation.
  - pfdietz 3y ago
    Powering the world (all energy, not just the grid, and not just the grid in the US) with PWRs won't work, because we run out of cheap uranium too quickly. Breeding is needed for sustainable use of nuclear.
    - Manuel_D 3y ago
      Incorrect, we have plenty of uranium both terrestrially and through seawater extraction: https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/ https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s... Sure seawater extraction is more expensive. But procuring raw uranium is a tiny fraction of nuclear's cost. You'll see statistics saying nuclear fuel is a significant cost, but most of that expense is from enrichment not extracting raw uranium.
      - pfdietz 3y ago
        Seawater extraction is even less plausible than breeders. The polyamidoxime fibers that article discusses do not have sufficiently long service lives. Also, if the uranium were to be burned in PWRs, the effective power per ocean area of uranium collectors would be much less than the effective power/area from photovoltaics. Uranium is a small fraction of nuclear's cost at current uranium prices. But eventually that runs out, and the price of uranium would increase dramatically. This has always been the motivation for breeders.
        Manuel_D 3y ago
        Again, the energy density of uranium is such that even if seawater extraction remains expensive, it has negligible impact on nuclear power costs: https://en.m.wikipedia.org/wiki/Economics_of_nuclear_power_plants https://en.m.wikipedia.org/wiki/Economics_of_nuclear_power_p... > The cost of raw uranium contributes about $0.0015/kWh Even if this increases by an order of magnitude, this is not significantly impacting the cost of nuclear power. Heck, even two orders of magnitude still amounts to ~1% increase in net cost per KWh. RE your edit after I commented: > Uranium is a small fraction of nuclear's cost at current uranium prices. But eventually that runs out, and the price of uranium would increase dramatically. This has always been the motivation for breeders. Again, the cost of raw uranium extraction amounts to $0.0015/kWh in nuclear generation. A 100x cost increase will not amount to even a quarter of a cent per KWh. This is the power of fissile energy density: it's so energy dense that the cost of extraction is largely decoupled from the net cost of nuclear power. By comparison, how would the price of lithium ion batteries be affected if the price of lithium carbonate increases by 100x? Half of a battery's cost comes from the cost of cathode material: https://www.visualcapitalist.com/breaking-down-the-cost-of-an-ev-battery-cell/ https://www.visualcapitalist.com/breaking-down-the-cost-of-a...
        philipkglass 3y ago
        If $0.0015/kWh is the current fuel cost, a 100x increase would bring it up to $0.15/kWh. That's 15 cents per kilowatt hour, not a fraction of a cent. It would make nuclear power among the most expensive of electricity sources from fuel cost alone.

pfdietz 3y ago

In the same sense that commercial breeder reactors are theoretical (which is conservative, as you can't actually buy a breeder reactor). But nuclear advocates don't talk about those much, even though they'd be needed for a nuclear powered world.

Manuel_D 3y ago
But we don't need commerical breeder reactors. The USA just needs to build 4 PWRs for each reactor it presently has to generate electricity entirely from hydro and nuclear. This is vastly more feasible than provisioning terawatt hours of energy storage. "Just scale up" is a good summary of how to decarbonize through nuclear power. We have decades of experience building nuclear plants. Not so with hydrogen based electricity storage. Plans for renewable grids call for the use of novel electricity storage systems because none of the existing storage mechanisms are feasible. Until we've built the storage mechanisms proposed, any plan involving it's use is effectively hand-waving a big part of its implementation.
- pfdietz 3y ago
  Powering the world (all energy, not just the grid, and not just the grid in the US) with PWRs won't work, because we run out of cheap uranium too quickly. Breeding is needed for sustainable use of nuclear.
  - Manuel_D 3y ago
    Incorrect, we have plenty of uranium both terrestrially and through seawater extraction: https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/ https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s... Sure seawater extraction is more expensive. But procuring raw uranium is a tiny fraction of nuclear's cost. You'll see statistics saying nuclear fuel is a significant cost, but most of that expense is from enrichment not extracting raw uranium.
    - pfdietz 3y ago
      Seawater extraction is even less plausible than breeders. The polyamidoxime fibers that article discusses do not have sufficiently long service lives. Also, if the uranium were to be burned in PWRs, the effective power per ocean area of uranium collectors would be much less than the effective power/area from photovoltaics. Uranium is a small fraction of nuclear's cost at current uranium prices. But eventually that runs out, and the price of uranium would increase dramatically. This has always been the motivation for breeders.
      - Manuel_D 3y ago
        Again, the energy density of uranium is such that even if seawater extraction remains expensive, it has negligible impact on nuclear power costs: https://en.m.wikipedia.org/wiki/Economics_of_nuclear_power_plants https://en.m.wikipedia.org/wiki/Economics_of_nuclear_power_p... > The cost of raw uranium contributes about $0.0015/kWh Even if this increases by an order of magnitude, this is not significantly impacting the cost of nuclear power. Heck, even two orders of magnitude still amounts to ~1% increase in net cost per KWh. RE your edit after I commented: > Uranium is a small fraction of nuclear's cost at current uranium prices. But eventually that runs out, and the price of uranium would increase dramatically. This has always been the motivation for breeders. Again, the cost of raw uranium extraction amounts to $0.0015/kWh in nuclear generation. A 100x cost increase will not amount to even a quarter of a cent per KWh. This is the power of fissile energy density: it's so energy dense that the cost of extraction is largely decoupled from the net cost of nuclear power. By comparison, how would the price of lithium ion batteries be affected if the price of lithium carbonate increases by 100x? Half of a battery's cost comes from the cost of cathode material: https://www.visualcapitalist.com/breaking-down-the-cost-of-an-ev-battery-cell/ https://www.visualcapitalist.com/breaking-down-the-cost-of-a...
        philipkglass 3y ago
        If $0.0015/kWh is the current fuel cost, a 100x increase would bring it up to $0.15/kWh. That's 15 cents per kilowatt hour, not a fraction of a cent. It would make nuclear power among the most expensive of electricity sources from fuel cost alone.