5 ms·

> If you build the solar and wind you don't need the nuclear. Don't forget the enormous battery arrays for winter, cloudy skies, or wildfire smoke. Hope you ha

> If you build the solar and wind you don't need the nuclear. Don't forget the enormous battery arrays for winter, cloudy skies, or wildfire smoke. Hope you have enough batteries. But you won't, so ok, now you need gas reactors to fill in the blanks. Isn't that what we're trying to get away from?

pfdietz 3mo ago
Ah yes, the ridiculous strawman engineering of saying batteries would be used for seasonal storage.
- troupo 3mo ago
  Then what would you use for seasonal storage?
  - arkh 3mo ago
    > Then what would you use for seasonal storage? Like Germany: coal and the energy provided by the rest of the EU. So Nordic countries hydro and nuclear, and some French nuclear. While lobbying to make all those interconnections increase domestic prices for the providers.
    - troupo 3mo ago
      > Like Germany: coal and the energy provided by the rest of the EU. So, from actual non-intermittent sources like checks notes nuclear?
      - pfdietz 3mo ago
        No, nuclear is terrible for covering seasonality, since unless it's used with high capacity factor the cost per kWh skyrockets.
        troupo 3mo ago
        > No, nuclear is terrible for covering seasonality, wat How is nuclear bad at covering the seasonality of, for example, winter in the Nordics?
        pfdietz 3mo ago
        It's best for covering a constant demand, not a seasonal component of demand. If renewables grow to the point where there is no remaining near-constant unmet demand, nuclear has no place at all.
        Moldoteck 3mo ago
        No, it's ok if you schedule maintenance during summer. And with more AC adoption you'll partially reduce this heavy swing. Nuclear at 60%cf is still economical. The problem arises if your plant takes 20y and 20bn to build
  - pfdietz 3mo ago
    In the short term, one would burn natural gas in turbines. The marginal cost of displacing this by using nuclear instead would lead to an enormous cost per unit of CO2 avoided, so high that most other uses of fossil fuels would be eliminated first (like, all use in ground vehicles). In the long term, either non-fossil fuels burned in turbines (e-fuels like hydrogen or biofuels), or bulk thermal storage of renewable electricity. These both have lousy round trip efficiency (maybe 40%), but that's still cheaper than using batteries, because the capex per unit of storage capacity is far lower, and the cost of the RTE is low when there are so few charge-discharge cycles (as happens with seasonal storage); cost of seasonal storage is dominated by capex, which is why using high-capex batteries for it is such a bad idea. Personally, I consider bulk thermal storage of cheap DC-coupled PV the most promising approach, as being pursued by Standard Thermal. They claim to be able to deliver 365/24/7 heat at 600 C for $3-5/GJ, which is competitive with Henry Hub natural gas.
    - consensus1 3mo ago
      I would prefer to reduce emissions using technology that exists today, I know it works, and I have seen it operate at national grid scale, not speculative future tech.
      - pfdietz 3mo ago
        You do highlight something there: the case for nuclear requires one to assume that the competing technologies stop their rapid advance. If not, the 40 (or 60, or 80) year investment horizons needed to partially shore up the bad economics of nuclear become utterly absurd. (The criticism that renewables don't last as long as nuclear suddenly looks like praise when viewed in this light; renewables don't need those very long time horizons to pay out.) But making this bet, that renewables will suddenly come up short, that the experience curves will suddenly break their historic trends on the log-log plot, has never worked out well. Something like hydrogen seems guaranteed to be available if needed. Realize that green hydrogen is needed even in a nuclear-powered world, because of existing hydrogen demand that is currently satisfied by steam reforming of fossil fuels (mostly natural gas). So lots of hydrogen will be made; it doesn't require new technology to make some more. I'll add that if you are sticking to currently available commercial technologies, nuclear is a loser, since burner reactors are far too fuel-inefficient to last very long on existing estimated uranium resources. The current estimate of uranium resources at 3x current price would provide the world's current rate of primary energy demand for just 5 years, if burner reactors were used.

pfdietz 3mo ago

Ah yes, the ridiculous strawman engineering of saying batteries would be used for seasonal storage.

troupo 3mo ago
Then what would you use for seasonal storage?
- arkh 3mo ago
  > Then what would you use for seasonal storage? Like Germany: coal and the energy provided by the rest of the EU. So Nordic countries hydro and nuclear, and some French nuclear. While lobbying to make all those interconnections increase domestic prices for the providers.
  - troupo 3mo ago
    > Like Germany: coal and the energy provided by the rest of the EU. So, from actual non-intermittent sources like checks notes nuclear?
    - pfdietz 3mo ago
      No, nuclear is terrible for covering seasonality, since unless it's used with high capacity factor the cost per kWh skyrockets.
      - troupo 3mo ago
        > No, nuclear is terrible for covering seasonality, wat How is nuclear bad at covering the seasonality of, for example, winter in the Nordics?
        pfdietz 3mo ago
        It's best for covering a constant demand, not a seasonal component of demand. If renewables grow to the point where there is no remaining near-constant unmet demand, nuclear has no place at all.
      - Moldoteck 3mo ago
        No, it's ok if you schedule maintenance during summer. And with more AC adoption you'll partially reduce this heavy swing. Nuclear at 60%cf is still economical. The problem arises if your plant takes 20y and 20bn to build
- pfdietz 3mo ago
  In the short term, one would burn natural gas in turbines. The marginal cost of displacing this by using nuclear instead would lead to an enormous cost per unit of CO2 avoided, so high that most other uses of fossil fuels would be eliminated first (like, all use in ground vehicles). In the long term, either non-fossil fuels burned in turbines (e-fuels like hydrogen or biofuels), or bulk thermal storage of renewable electricity. These both have lousy round trip efficiency (maybe 40%), but that's still cheaper than using batteries, because the capex per unit of storage capacity is far lower, and the cost of the RTE is low when there are so few charge-discharge cycles (as happens with seasonal storage); cost of seasonal storage is dominated by capex, which is why using high-capex batteries for it is such a bad idea. Personally, I consider bulk thermal storage of cheap DC-coupled PV the most promising approach, as being pursued by Standard Thermal. They claim to be able to deliver 365/24/7 heat at 600 C for $3-5/GJ, which is competitive with Henry Hub natural gas.
  - consensus1 3mo ago
    I would prefer to reduce emissions using technology that exists today, I know it works, and I have seen it operate at national grid scale, not speculative future tech.
    - pfdietz 3mo ago
      You do highlight something there: the case for nuclear requires one to assume that the competing technologies stop their rapid advance. If not, the 40 (or 60, or 80) year investment horizons needed to partially shore up the bad economics of nuclear become utterly absurd. (The criticism that renewables don't last as long as nuclear suddenly looks like praise when viewed in this light; renewables don't need those very long time horizons to pay out.) But making this bet, that renewables will suddenly come up short, that the experience curves will suddenly break their historic trends on the log-log plot, has never worked out well. Something like hydrogen seems guaranteed to be available if needed. Realize that green hydrogen is needed even in a nuclear-powered world, because of existing hydrogen demand that is currently satisfied by steam reforming of fossil fuels (mostly natural gas). So lots of hydrogen will be made; it doesn't require new technology to make some more. I'll add that if you are sticking to currently available commercial technologies, nuclear is a loser, since burner reactors are far too fuel-inefficient to last very long on existing estimated uranium resources. The current estimate of uranium resources at 3x current price would provide the world's current rate of primary energy demand for just 5 years, if burner reactors were used.