3 ms·

> And ironically some of the solutions proposed for the downsides of nuclear are also what you need for renewables, i.e. storage to maximize use of expensive in

by pyrale 4y ago

> And ironically some of the solutions proposed for the downsides of nuclear are also what you need for renewables, i.e. storage to maximize use of expensive infrastructure with low opex. It's exhausting to see this claim see the light so often, despite being debunked so frequently. Nuclear doesn't require storage. Some people claim that economies could be made with storage because then you wouldn't need to build production equivalent to 100% of your peak consumption. The dishonest discourse happens when renewables proponent claim that this small potential optimization means nuclear needs storage just as much as renewables do. Actually, losing your power source is not equivalent to shaving a few %s of budget. This idea also completely ignores the fact that power grids don't optimize for efficiency, but for stability. We want redundant production, and the ability to move as many cursors as possible on the grid, in order to balance for issues. The ability to ramp up a power plant isn't just useful to produce peak load, it also helps mitigating e.g. losing a power line or a power transformer.

Gwypaas 4y ago
Assume a capacity factor of 50% then to handle peak loads? Now the nuclear costs $240-440/MWh. That is ridiculous costs, worse than Europe during the last winters Russian war induced gas crisis. https://www.lazard.com/research-insights/levelized-cost-of-energyplus/ https://www.lazard.com/research-insights/levelized-cost-of-e...
- pyrale 4y ago
  It's hard to give numbers for 100% nuclear since no one does that, but yes, France has load factors between 60 and 80% depending on the reactor type. https://www.iaea.org/fr/newscenter/news/contribution-du-nucleaire-a-la-securite-energetique-en-augmentant-la-production-delectricite-en-2021 https://www.iaea.org/fr/newscenter/news/contribution-du-nucl... The report you quote already cites load factor around 90% for new builds, a 50% load factor wouldn't double the costs. That being said, 90% load factor for a grid with a high share of nuclear is probably extremely optimistic. The reason such high capacity factors can be reached in countries that have a low nuclear share is that nuclear has an extremely low marginal cost, and is always picked over plants that require fuel.
  - Certhas 4y ago
    Once you electrify your heat demand seasonal variability will massively increase, driving down load factors dramatically. Today electricity accounts for 20% of energy use, European estimates see that going up to 50% by 2050. A large chunk of that increase is heating. Obviously other countries and climates will not see the same patterns here.
  - Gwypaas 4y ago
    True, the fixed costs are $20-35/MWh. Deduct that from the figure before doubling. Not that it matters. Running a pure nuclear grid will never get 90% capacity factor. That relies on only taking the base load and offloading the actual hard part to other generators. Exactly what nuclear proponents like to say will be impossible for renewables.
    - pyrale 4y ago
      > That relies on only taking the base load and offloading the actual hard part to other generators. Exactly what nuclear proponents like to say will be impossible for renewables. It's certainly not impossible, since that's what we do currently. The reason we would like to stop doing it in the future is co2 emissions, not a feasibility barrier. Now my point was that we don't have experience of massive storage. And in the absence of storage, nuclear costs go up, while renewables output goes down. One is painful but manageable, we don't have a plan to handle the other. Personally, I wish we spent a bit less subsidies on renewable production, and a bit more on grid-sized storage, so we can have an answer on costs. Without this, discussions on storage-enabled grids are conjectures at best.
Certhas 4y ago
For the benefit of the bystander: this person actually has no idea what energy seen planning looks like in real life. Economic optimization is absolutely at the core of it. Energy System Models (Essen) are economic optimization models. Depending on country and climate, the factor of the sibling comment of 50% is absolutely realistic. Also these details don't really matter: Storage is a viable solution to the problem that Renewables are not dispatch able. The only argument against storage could be economic: That the inefficiencies and cost of storage render nuclear cheaper after all.
- pyrale 4y ago
  Not sure whether you understand the difference between the prospective world of public analysts, and actually running a power grid. I know there can be a divide between the two, and some self-agrandizement on each side. Picking reliability over efficiency is the sound economic choice. Please note that my comment is not about the viability of storage for renewables.
  - Certhas 4y ago
    I semi-regularly talk to people that plan the European power grid, yes. At the core of extension and development studies is still an optimal power flow, which is an economic optimization. Stability (which has many meanings here) is usually studied as a second step. Security of Supply is yet another issue. Anyway, if you can use storage to lower you nuclear costs by 5% overall, would it not be used? If your comment is not about viability of large scale storage, then what is it about? Storage is dispatchable, and an economically optimal 100% renewables grid will have a peak capacity far above actual peak demand, meaning it's typically curtailed (or you run electrolysers which again can beade dispatchable and grid-forming as loads) which again means you have plenty of ability to react. Resilience research tends to favor decentralized solutions as well. Look at how Puerto Rico is being rebuilt.
    - pyrale 4y ago
      > I semi-regularly talk to people that plan the European power grid, yes. Hard to know which group of people you talk to. This kind of work happens at many different levels, for many different reasons. TSO investment decisions are not made by the same people than power production investment decisions. There is some coordination, but no centralized decision-making. To the best of my knowledge of at least one major European TSO, investment decisions are not taken at european level. And while there is strong european coordination in grid management, it is still cooperation and not an unified decision process. Any europe-level investment advice would have to be evaluated and selected by the TSO to become effective. Also the further you go from the field, the more likely studies are to consider spherical cows. Still useful, but not the full picture. > Anyway, if you can use storage to lower you nuclear costs by 5% overall, would it not be used? Of course it would, and we do use reversible dams to optimize costs. My point is that: 1) that's a whole-production optimization, and the trigger for that optimization is increasingly renewables rather than optimizing for nuclear production stability 2) the difference between paying 5% more and having to cut consumers from the grid is massive. for any TSO trying to save money is a goal, but curtailing consumption is an absolute failure criterion, second only to damaging the grid itself. > Resilience research tends to favor decentralized solutions as well. I might be biased by my personal experience, but when it comes to a power grid, planning ahead of time is much more valuable than decentralization. There is a difference between avoiding concentration of material, something which can be handled with central oversignt, and decentralization, which creates a coordination cost and sometimes loss of information (which is the case when small renewable production is connected to the distribution network rather than the transport network).

by pyrale 4y ago

Gwypaas 4y ago

Assume a capacity factor of 50% then to handle peak loads? Now the nuclear costs $240-440/MWh. That is ridiculous costs, worse than Europe during the last winters Russian war induced gas crisis. https://www.lazard.com/research-insights/levelized-cost-of-energyplus/ https://www.lazard.com/research-insights/levelized-cost-of-e...

pyrale 4y ago
It's hard to give numbers for 100% nuclear since no one does that, but yes, France has load factors between 60 and 80% depending on the reactor type. https://www.iaea.org/fr/newscenter/news/contribution-du-nucleaire-a-la-securite-energetique-en-augmentant-la-production-delectricite-en-2021 https://www.iaea.org/fr/newscenter/news/contribution-du-nucl... The report you quote already cites load factor around 90% for new builds, a 50% load factor wouldn't double the costs. That being said, 90% load factor for a grid with a high share of nuclear is probably extremely optimistic. The reason such high capacity factors can be reached in countries that have a low nuclear share is that nuclear has an extremely low marginal cost, and is always picked over plants that require fuel.
- Certhas 4y ago
  Once you electrify your heat demand seasonal variability will massively increase, driving down load factors dramatically. Today electricity accounts for 20% of energy use, European estimates see that going up to 50% by 2050. A large chunk of that increase is heating. Obviously other countries and climates will not see the same patterns here.
- Gwypaas 4y ago
  True, the fixed costs are $20-35/MWh. Deduct that from the figure before doubling. Not that it matters. Running a pure nuclear grid will never get 90% capacity factor. That relies on only taking the base load and offloading the actual hard part to other generators. Exactly what nuclear proponents like to say will be impossible for renewables.
  - pyrale 4y ago
    > That relies on only taking the base load and offloading the actual hard part to other generators. Exactly what nuclear proponents like to say will be impossible for renewables. It's certainly not impossible, since that's what we do currently. The reason we would like to stop doing it in the future is co2 emissions, not a feasibility barrier. Now my point was that we don't have experience of massive storage. And in the absence of storage, nuclear costs go up, while renewables output goes down. One is painful but manageable, we don't have a plan to handle the other. Personally, I wish we spent a bit less subsidies on renewable production, and a bit more on grid-sized storage, so we can have an answer on costs. Without this, discussions on storage-enabled grids are conjectures at best.

Certhas 4y ago

For the benefit of the bystander: this person actually has no idea what energy seen planning looks like in real life. Economic optimization is absolutely at the core of it. Energy System Models (Essen) are economic optimization models. Depending on country and climate, the factor of the sibling comment of 50% is absolutely realistic. Also these details don't really matter: Storage is a viable solution to the problem that Renewables are not dispatch able. The only argument against storage could be economic: That the inefficiencies and cost of storage render nuclear cheaper after all.

pyrale 4y ago
Not sure whether you understand the difference between the prospective world of public analysts, and actually running a power grid. I know there can be a divide between the two, and some self-agrandizement on each side. Picking reliability over efficiency is the sound economic choice. Please note that my comment is not about the viability of storage for renewables.
- Certhas 4y ago
  I semi-regularly talk to people that plan the European power grid, yes. At the core of extension and development studies is still an optimal power flow, which is an economic optimization. Stability (which has many meanings here) is usually studied as a second step. Security of Supply is yet another issue. Anyway, if you can use storage to lower you nuclear costs by 5% overall, would it not be used? If your comment is not about viability of large scale storage, then what is it about? Storage is dispatchable, and an economically optimal 100% renewables grid will have a peak capacity far above actual peak demand, meaning it's typically curtailed (or you run electrolysers which again can beade dispatchable and grid-forming as loads) which again means you have plenty of ability to react. Resilience research tends to favor decentralized solutions as well. Look at how Puerto Rico is being rebuilt.
  - pyrale 4y ago
    > I semi-regularly talk to people that plan the European power grid, yes. Hard to know which group of people you talk to. This kind of work happens at many different levels, for many different reasons. TSO investment decisions are not made by the same people than power production investment decisions. There is some coordination, but no centralized decision-making. To the best of my knowledge of at least one major European TSO, investment decisions are not taken at european level. And while there is strong european coordination in grid management, it is still cooperation and not an unified decision process. Any europe-level investment advice would have to be evaluated and selected by the TSO to become effective. Also the further you go from the field, the more likely studies are to consider spherical cows. Still useful, but not the full picture. > Anyway, if you can use storage to lower you nuclear costs by 5% overall, would it not be used? Of course it would, and we do use reversible dams to optimize costs. My point is that: 1) that's a whole-production optimization, and the trigger for that optimization is increasingly renewables rather than optimizing for nuclear production stability 2) the difference between paying 5% more and having to cut consumers from the grid is massive. for any TSO trying to save money is a goal, but curtailing consumption is an absolute failure criterion, second only to damaging the grid itself. > Resilience research tends to favor decentralized solutions as well. I might be biased by my personal experience, but when it comes to a power grid, planning ahead of time is much more valuable than decentralization. There is a difference between avoiding concentration of material, something which can be handled with central oversignt, and decentralization, which creates a coordination cost and sometimes loss of information (which is the case when small renewable production is connected to the distribution network rather than the transport network).