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Nuclear is a great compliment to photovoltaic. One of the reasons Japan was able to go large on PV (and cause prices to come down for the rest of us) was their

Nuclear is a great compliment to photovoltaic. One of the reasons Japan was able to go large on PV (and cause prices to come down for the rest of us) was their huge pumped water infrastructure that had been built for nuclear. One problem with nuclear was all the excess power created at night, so they would pump water uphill at night and then run it down to generate power at the daytime peaks. Of course with PV the timing was reversed but the need similar. If they hadn’t decommissioned their nuclear plants the combination would have been even better.

pfdietz 7y ago
Nuclear is not a great complement to PV, if the PV is cheap. Cheap PV expands until there is no residual baseload demand left. At that point, nuclear power plants cannot maintain high capacity factor and their economics go all to hell.
- AnthonyMouse 7y ago
  Nuclear has effectively zero unit cost, it's all fixed cost. Once you build the reactor, you generate at full capacity all day and night and take whatever the market rate is. That means you get paid less during the day when solar is the cheapest provider, but you still match its price and supply your full generation capacity even then, because you can, because anything is more than nothing and the incremental generation cost is effectively zero. Then you make more at night when solar requires storage, and even more still whenever the day was overcast and energy prices had to rise high enough to suppress demand enough that the depleted storage isn't fully exhausted before sunrise. The capacity factor is always 100%, it's the price you get at any given time that varies. But price variability in itself is no problem either, as long as the average price is above average cost. And that average includes not only times that it rains for multiple days in a row, but also winter, and that with consideration of people also needing to switch from oil and gas to electric heat.
  - Marazan 7y ago
    No
    - steve1011 7y ago
      good point lol
      - Marazan 7y ago
        I thought it was strong.
  - pfdietz 7y ago
    "as long as the average price is above average cost" And that's the killer. Add enough solar and wind and the average price craters, even if solar and wind cannot handle everything (without help from dispatchable sources and/or storage).
    - AnthonyMouse 7y ago
      The problem with that argument is that it proves too much. It applies to everything, because solar and wind are the same as nuclear, their incremental generation cost is effectively zero once the capital is paid, so you take whatever the market price is. Which means you have a problem. It's physically possible to build enough solar and wind and storage to even handle extended periods of low sun and low wind. But if you do that then on a normal day with a normal amount of sun and wind, you have a large oversupply and the price falls to zero and everybody goes bankrupt. That happens less if you add real baseload like nuclear to the mix, because something with a fixed generation capacity doesn't have a periodic shortage requiring you to compensate with an overcapacity which bankrupts everybody on a normal day.
      - pfdietz 7y ago
        Solar and wind will build out until it is no longer profitable to do so. That means: when they have driven the price of electricity when they are operating, averaged over time, down to the point they can't get a return on investment. This price point is far below where new nuclear needs it to be for nuclear to earn back its construction and operating costs. What drives all this is that the levelized cost of energy from solar and wind is much less (a factor of 3 or 4) than the levelized cost of energy from new nuclear plants. Nuclear, or at least many existing nuclear plants, has an additional disadvantage: it cannot cut output rapidly. If power from renewables suddenly floods the market, prices can go negative. Renewables can just stop selling in that situation, but nuclear is forced to continued to run and eat the negative revenue. The low power density of the renewables sources, usually depicted as a negative, is the source of this advantage: sunlight absorbed in PV modules can just be allowed to dissipate as heat there with no negative effects. (In fairness, I should also mention that there are subsidies in the US that encourage renewables to keep generating even at negative prices. These subsidies will have to go at some point, and perhaps that point is now.) What will be the final death knell for nuclear will be when short term storage gets cheap enough that the times when that's discharging will also be economic death zones for nuclear plants. I expect few of the existing operating nuclear power plants to survive after that.
- paulsutter 7y ago
  PV for baseload? How does that work? Everyone will use candles at night?
  - pfdietz 7y ago
    > PV for baseload? It's remarkable you were able to read that into what I wrote, when that wasn't at all what I wrote. The point I was making was that intermittent renewables can screw up the market for nuclear, even if the renewables themselves do not supply baseload. You may be under the misapprehension that if there is a base level of demand on the grid, then that base level of demand can only be supplied by baseload power sources like nuclear or coal. This is not the case. It was in the case in the past that baseload sources were the cheapest way to satisfy that demand, but there's no law of physics or economics that requires that to always be true. And increasingly it's NOT true.
    - paulsutter 7y ago
      Right but only because you’re ignoring storage which is the only way to make PV really work (duck curve is an absurdity caused by lack of storage). Sorry I missed your point, but your still misunderstanding what’s needed.
      - pfdietz 7y ago
        Renewables can ruin the market for nuclear even without storage. Adding economical short term storage (we're close with batteries, and almost certainly will have it before any nuclear plant whose construction was green-lit today could be completed) and nuclear is not just in trouble, it is dead.

pfdietz 7y ago

Nuclear is not a great complement to PV, if the PV is cheap. Cheap PV expands until there is no residual baseload demand left. At that point, nuclear power plants cannot maintain high capacity factor and their economics go all to hell.

AnthonyMouse 7y ago
Nuclear has effectively zero unit cost, it's all fixed cost. Once you build the reactor, you generate at full capacity all day and night and take whatever the market rate is. That means you get paid less during the day when solar is the cheapest provider, but you still match its price and supply your full generation capacity even then, because you can, because anything is more than nothing and the incremental generation cost is effectively zero. Then you make more at night when solar requires storage, and even more still whenever the day was overcast and energy prices had to rise high enough to suppress demand enough that the depleted storage isn't fully exhausted before sunrise. The capacity factor is always 100%, it's the price you get at any given time that varies. But price variability in itself is no problem either, as long as the average price is above average cost. And that average includes not only times that it rains for multiple days in a row, but also winter, and that with consideration of people also needing to switch from oil and gas to electric heat.
- Marazan 7y ago
  No
  - steve1011 7y ago
    good point lol
    - Marazan 7y ago
      I thought it was strong.
- pfdietz 7y ago
  "as long as the average price is above average cost" And that's the killer. Add enough solar and wind and the average price craters, even if solar and wind cannot handle everything (without help from dispatchable sources and/or storage).
  - AnthonyMouse 7y ago
    The problem with that argument is that it proves too much. It applies to everything, because solar and wind are the same as nuclear, their incremental generation cost is effectively zero once the capital is paid, so you take whatever the market price is. Which means you have a problem. It's physically possible to build enough solar and wind and storage to even handle extended periods of low sun and low wind. But if you do that then on a normal day with a normal amount of sun and wind, you have a large oversupply and the price falls to zero and everybody goes bankrupt. That happens less if you add real baseload like nuclear to the mix, because something with a fixed generation capacity doesn't have a periodic shortage requiring you to compensate with an overcapacity which bankrupts everybody on a normal day.
    - pfdietz 7y ago
      Solar and wind will build out until it is no longer profitable to do so. That means: when they have driven the price of electricity when they are operating, averaged over time, down to the point they can't get a return on investment. This price point is far below where new nuclear needs it to be for nuclear to earn back its construction and operating costs. What drives all this is that the levelized cost of energy from solar and wind is much less (a factor of 3 or 4) than the levelized cost of energy from new nuclear plants. Nuclear, or at least many existing nuclear plants, has an additional disadvantage: it cannot cut output rapidly. If power from renewables suddenly floods the market, prices can go negative. Renewables can just stop selling in that situation, but nuclear is forced to continued to run and eat the negative revenue. The low power density of the renewables sources, usually depicted as a negative, is the source of this advantage: sunlight absorbed in PV modules can just be allowed to dissipate as heat there with no negative effects. (In fairness, I should also mention that there are subsidies in the US that encourage renewables to keep generating even at negative prices. These subsidies will have to go at some point, and perhaps that point is now.) What will be the final death knell for nuclear will be when short term storage gets cheap enough that the times when that's discharging will also be economic death zones for nuclear plants. I expect few of the existing operating nuclear power plants to survive after that.
paulsutter 7y ago
PV for baseload? How does that work? Everyone will use candles at night?
- pfdietz 7y ago
  > PV for baseload? It's remarkable you were able to read that into what I wrote, when that wasn't at all what I wrote. The point I was making was that intermittent renewables can screw up the market for nuclear, even if the renewables themselves do not supply baseload. You may be under the misapprehension that if there is a base level of demand on the grid, then that base level of demand can only be supplied by baseload power sources like nuclear or coal. This is not the case. It was in the case in the past that baseload sources were the cheapest way to satisfy that demand, but there's no law of physics or economics that requires that to always be true. And increasingly it's NOT true.
  - paulsutter 7y ago
    Right but only because you’re ignoring storage which is the only way to make PV really work (duck curve is an absurdity caused by lack of storage). Sorry I missed your point, but your still misunderstanding what’s needed.
    - pfdietz 7y ago
      Renewables can ruin the market for nuclear even without storage. Adding economical short term storage (we're close with batteries, and almost certainly will have it before any nuclear plant whose construction was green-lit today could be completed) and nuclear is not just in trouble, it is dead.