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Oh totally. If next gen nuclear can help decarbonize the last 10%, that would be great. However the tone in OP's comment seemed more like nuclear is our only ho

Oh totally. If next gen nuclear can help decarbonize the last 10%, that would be great. However the tone in OP's comment seemed more like nuclear is our only hope. When in reality it will likely be something to meet edge cases rather than base load.

pfdietz 7y ago
Nuclear is uniquely terrible at filling in the occasional time slices renewables cannot. Nuclear's economics degrade horribly when used at low capacity factor like that. They are not complementary sources.
- Robotbeat 7y ago
  You would use the nuclear resource constantly, just like solar and wind. Can schedule refueling and maintenance in summer when there’s plenty of sun. Additionally: thermal plants like nuclear are more efficient in the winter (particularly if you add a bottoming cycle), meaning they generate more power right when they’re needed.
  - pfdietz 7y ago
    But then you're paying the much higher levelized cost of nuclear (and it is much higher, a factor of perhaps 4 or more) when the solar or wind or solar/wind in short term storage are available. So this doesn't work either. As I said, solar/wind and nuclear are not complementary. They're in competition.
    - Robotbeat 7y ago
      It doesn’t matter. We can no longer use fossil fuels any longer, and the amount we’d need to curtail wind and solar in the wintertime, even with a day or two of storage, is so high that nuclear is competitive & extremely helpful. Northern nations are going to have to decarbonize heating as well at the time of year when solar is at its worst. They really should be using nuclear.
      - pfdietz 7y ago
        No, I don't think that's the case. I think if you optimize out a CO2-grid using realistic assumptions about where the costs of renewables, storage, and nuclear will be in ten years, it will optimize out to 0% nuclear. There may still be reactors operating at that time, but they will be lame ducks with their construction costs already sunk.
        Robotbeat 7y ago
        I think you haven't done such calculations. I have. At high latitudes, nuclear is competitive.
        pfdietz 7y ago
        Or perhaps we have different ideas of what "reasonable" assumptions about costs will be in ten years. I expect nuclear to show little or no cost decline in that time. And I expect renewables to have shown large continued declines. I expect solar to have fallen by a factor of 2. Given that sort of decline, even low efficiency seasonal storage could beat nuclear. High latitude regions -- what latitude are you talking about? 95% of the world's population is below 50 N/S. For the few in true polar regions, I suggest solar + moderate temperature geothermal could be a good combination. Geothermal would be used in the winter, when a very low temperature heat sink is available. In a solar dominated future, I expect those high latitude regions to eventually lose most of their energy-intensive industry. They will not be able to compete with industries at lower latitude with better access to cheaper solar power. Having expensive nuclear available there will not save them from this.
        Robotbeat 7y ago
        To assume nuclear won't be making any cost reductions is to basically beg the question. We're discussing whether we should invest in nuclear. Renewables have reduced in price because of investment. Nuclear has not because we have dramatically reduced our investments there over the last several decades. If we invest again in nuclear, there will be cost reductions from the learning curve. If we don't, there won't be cost reductions. IMHO, climate demands we invest in every promising resource. And that includes nuclear.

pfdietz 7y ago

Nuclear is uniquely terrible at filling in the occasional time slices renewables cannot. Nuclear's economics degrade horribly when used at low capacity factor like that. They are not complementary sources.

Robotbeat 7y ago
You would use the nuclear resource constantly, just like solar and wind. Can schedule refueling and maintenance in summer when there’s plenty of sun. Additionally: thermal plants like nuclear are more efficient in the winter (particularly if you add a bottoming cycle), meaning they generate more power right when they’re needed.
- pfdietz 7y ago
  But then you're paying the much higher levelized cost of nuclear (and it is much higher, a factor of perhaps 4 or more) when the solar or wind or solar/wind in short term storage are available. So this doesn't work either. As I said, solar/wind and nuclear are not complementary. They're in competition.
  - Robotbeat 7y ago
    It doesn’t matter. We can no longer use fossil fuels any longer, and the amount we’d need to curtail wind and solar in the wintertime, even with a day or two of storage, is so high that nuclear is competitive & extremely helpful. Northern nations are going to have to decarbonize heating as well at the time of year when solar is at its worst. They really should be using nuclear.
    - pfdietz 7y ago
      No, I don't think that's the case. I think if you optimize out a CO2-grid using realistic assumptions about where the costs of renewables, storage, and nuclear will be in ten years, it will optimize out to 0% nuclear. There may still be reactors operating at that time, but they will be lame ducks with their construction costs already sunk.
      - Robotbeat 7y ago
        I think you haven't done such calculations. I have. At high latitudes, nuclear is competitive.
        pfdietz 7y ago
        Or perhaps we have different ideas of what "reasonable" assumptions about costs will be in ten years. I expect nuclear to show little or no cost decline in that time. And I expect renewables to have shown large continued declines. I expect solar to have fallen by a factor of 2. Given that sort of decline, even low efficiency seasonal storage could beat nuclear. High latitude regions -- what latitude are you talking about? 95% of the world's population is below 50 N/S. For the few in true polar regions, I suggest solar + moderate temperature geothermal could be a good combination. Geothermal would be used in the winter, when a very low temperature heat sink is available. In a solar dominated future, I expect those high latitude regions to eventually lose most of their energy-intensive industry. They will not be able to compete with industries at lower latitude with better access to cheaper solar power. Having expensive nuclear available there will not save them from this.
        Robotbeat 7y ago
        To assume nuclear won't be making any cost reductions is to basically beg the question. We're discussing whether we should invest in nuclear. Renewables have reduced in price because of investment. Nuclear has not because we have dramatically reduced our investments there over the last several decades. If we invest again in nuclear, there will be cost reductions from the learning curve. If we don't, there won't be cost reductions. IMHO, climate demands we invest in every promising resource. And that includes nuclear.