4 ms·

> You can absolutely build solar+wind+storage systems that deliver 24/7/365 energy with many nines SLAs, on the real earth with real statistics on weather. Onc

> You can absolutely build solar+wind+storage systems that deliver 24/7/365 energy with many nines SLAs, on the real earth with real statistics on weather. Once you start adding nines, nuclear starts to be become attractive again. Hence these deals.

pjc50 2y ago
> Once you start adding nines, nuclear starts to be become attractive again. Only if you ignore reliability issues with nuclear, such as France having to take a lot of reactors offline at the same time to check for cracks. The comparison has to be fair.
- closewith 2y ago
  Well, that's a false dichotomy, because no-one's (at least no-one reasonable and in good faith) is suggesting shifting the grid entirely to nuclear. Instead, a diverse set of generation sources is ideal, including solar, wind, nuclear and hydro.
  - pjc50 2y ago
    Dunno, all the nuclear advocates seem to contrast it with wind/solar, which are also much cheaper and quicker capital investments.
    - closewith 2y ago
      Well, the point of this thread is that's only true until a sufficient level of availability is required, and then nuclear (and fossil thermal plants) all of a sudden become a viable option again.
    - mpweiher 2y ago
      Nope, virtually all nuclear advocates call for combined renewable/nuclear grids. Nuclear and reliable renewables for base load, intermittent renewables for intermittent load where and when it matches. Wind/solar are not cheaper. Per kWh they are more expensive. Thanks to China, they are a lower and smaller-grained capital investment.
- mpweiher 2y ago
  Not the same scenario. First, France came through this just fine. Second, the could have kept those plants operating and taken a more piecemeal approach to fixing the cracks. They shouldn't have, and didn't, because you really want that triple or quadruple redundancy in your cooling systems, but they could have if push had come to shove, the plants were still operational. But since there was plenty of capacity available, they could afford to take those plants offline and do the checks and repairs all at once. Intermittent renewables afford you no such optionality. If the sun don't shine, the sun don't shine. If the wind don't blow, the wind don't blow.
- venj 2y ago
  This event happened in 2022. this is the only year since 1995 where nuclear production fell below 300TWh (278TWh in 2022 vs 360 in 2021 and 320 in 2023). These cracks are not the only factor for the poor performance on nuclear in 2022 : several reactors had to do their 10-year maintenance (grand carénage), which had been delayed because of the pandemic. It's hard to extrapolate reliability issues from an event that happened once in 30 years.
- wakawaka28 2y ago
  Why did they have to be checked all at once? That sounds like a design or regulation problem.
RandomLensman 2y ago
Practically, a lot of nuclear power plants can be down at the same time for maintenance etc., so you need to overbuild quite a bit there as well then
- dylan604 2y ago
  Hopefully you have multiple reactor designs so that if an issue with one is found, you don't stop all reactors just reactors of the same design.
- mpweiher 2y ago
  No. Nuclear power plants are super reliable and available. German und US plants had/have capacity factors of well over 90%, and the downtimes are scheduled. The "overbuild" is minimal.
  - RandomLensman 2y ago
    France in 2022 didn't have a lot of capacity down at the same time? Availability was at 40% of maximum capacity for about a month at it's lowest. How these things will be managed in the real world matters, too, not just how it could play out hypothetically.
    - mpweiher 2y ago
      Yep. That was a one-time occurrence, due to (a) inspections being deferred during COVID and (b) France's long time catastrophic underinvestment in their nuclear fleet. Until March 2023, there was a law in France that made it illegal to increase nuclear capacity in absolute terms and mandated reduction to under 50% in relative terms. https://www.youtube.com/watch?app=desktop&v=isgu-VrD0oM https://www.youtube.com/watch?app=desktop&v=isgu-VrD0oM But again, a one-time event, and it doesn't change the high capacity factors world-wide (over 80%) and the extremely high capacity factors in reasonably well run fleets ( > 90% in the US, and also inGermany when they still had nuclear ).
      - RandomLensman 2y ago

pjc50 2y ago

> Once you start adding nines, nuclear starts to be become attractive again. Only if you ignore reliability issues with nuclear, such as France having to take a lot of reactors offline at the same time to check for cracks. The comparison has to be fair.

closewith 2y ago
Well, that's a false dichotomy, because no-one's (at least no-one reasonable and in good faith) is suggesting shifting the grid entirely to nuclear. Instead, a diverse set of generation sources is ideal, including solar, wind, nuclear and hydro.
- pjc50 2y ago
  Dunno, all the nuclear advocates seem to contrast it with wind/solar, which are also much cheaper and quicker capital investments.
  - closewith 2y ago
    Well, the point of this thread is that's only true until a sufficient level of availability is required, and then nuclear (and fossil thermal plants) all of a sudden become a viable option again.
  - mpweiher 2y ago
    Nope, virtually all nuclear advocates call for combined renewable/nuclear grids. Nuclear and reliable renewables for base load, intermittent renewables for intermittent load where and when it matches. Wind/solar are not cheaper. Per kWh they are more expensive. Thanks to China, they are a lower and smaller-grained capital investment.
mpweiher 2y ago
Not the same scenario. First, France came through this just fine. Second, the could have kept those plants operating and taken a more piecemeal approach to fixing the cracks. They shouldn't have, and didn't, because you really want that triple or quadruple redundancy in your cooling systems, but they could have if push had come to shove, the plants were still operational. But since there was plenty of capacity available, they could afford to take those plants offline and do the checks and repairs all at once. Intermittent renewables afford you no such optionality. If the sun don't shine, the sun don't shine. If the wind don't blow, the wind don't blow.
venj 2y ago
This event happened in 2022. this is the only year since 1995 where nuclear production fell below 300TWh (278TWh in 2022 vs 360 in 2021 and 320 in 2023). These cracks are not the only factor for the poor performance on nuclear in 2022 : several reactors had to do their 10-year maintenance (grand carénage), which had been delayed because of the pandemic. It's hard to extrapolate reliability issues from an event that happened once in 30 years.
wakawaka28 2y ago
Why did they have to be checked all at once? That sounds like a design or regulation problem.

RandomLensman 2y ago

Practically, a lot of nuclear power plants can be down at the same time for maintenance etc., so you need to overbuild quite a bit there as well then

dylan604 2y ago
Hopefully you have multiple reactor designs so that if an issue with one is found, you don't stop all reactors just reactors of the same design.
mpweiher 2y ago
No. Nuclear power plants are super reliable and available. German und US plants had/have capacity factors of well over 90%, and the downtimes are scheduled. The "overbuild" is minimal.
- RandomLensman 2y ago
  France in 2022 didn't have a lot of capacity down at the same time? Availability was at 40% of maximum capacity for about a month at it's lowest. How these things will be managed in the real world matters, too, not just how it could play out hypothetically.
  - mpweiher 2y ago
    Yep. That was a one-time occurrence, due to (a) inspections being deferred during COVID and (b) France's long time catastrophic underinvestment in their nuclear fleet. Until March 2023, there was a law in France that made it illegal to increase nuclear capacity in absolute terms and mandated reduction to under 50% in relative terms. https://www.youtube.com/watch?app=desktop&v=isgu-VrD0oM https://www.youtube.com/watch?app=desktop&v=isgu-VrD0oM But again, a one-time event, and it doesn't change the high capacity factors world-wide (over 80%) and the extremely high capacity factors in reasonably well run fleets ( > 90% in the US, and also inGermany when they still had nuclear ).
    - RandomLensman 2y ago