> flexibility requirements are within these bounds. That means that power variations required can be serviced while staying within the limits of the system.
This is, indeed, central here.
It seems to me that, if nuclear can do all necessary follow-up (the fine, low-latency, the part of it which is at best not-well-planned and often absolutely not planned for), it should do so, as it is cheaper and emits less than any fossil-fuel-burning equipment.
I can only see two reasons for this:
- the price-calculation method (marginal cost...) used in Europe offers way more benefits by always producing the last kWh thanks to fossil fuel
- letting a fleet of nuclear reactors take on all necessary load-follow has some unwanted long-term effect (costs, maintenance, fuel state...)
Frequency controlling a grid (e.g. increasing or decreasing plant output by a few %s) is important for grid stability first and foremost. Grid costs are less important, and the process is not overseen by the producer, who bears the costs, but by the grid manager. Because of that, every power provider connected to the grid, is required to be able to provide some % of flexibility on its non-renewable fleet, including the providers who only operate fossil plants. For redundancy reasons and ease of implementation, this flexibility is split between as many plants as possible for each operator.
The step at which you can prioritize less costly means of production is scheduled ahead of time. This is when you typically need larger variations, such as moving a plant's output from 100% to 20%. In this step, merit order is used, and, to my knowledge, nuclear has priority over gas in France.
> Frequency controlling a grid (e.g. increasing or decreasing plant output by a few %s) is important for grid stability first and foremost. Grid costs are less important
> redundancy reasons and ease of implementation, this flexibility is split between as many plants as possible for each operator.
This is the core of the argument. My point is that if the nuclear fleet was flexible enough to provide 100% of the follow-up it would do so (because it emits less and costs less), and therefore production snapshots would rarely show significant production from flamme plants (burning fossil fuel), which would only be significant during peak consumption. In other words thanks to such a sufficient flexibility the merit-order could be sound at any moment. The reality is that those 'fossil' plants very often (nearly constantly) generate a fair fraction of the gridpower (they aren't in minimal production "ready to warm-start" mode, they generate in a useful way).
> The step at which you can prioritize less costly means of production is scheduled ahead of time. This is when you typically need larger variations, such as moving a plant's output from 100% to 20%. In this step, merit order is used, and, to my knowledge, nuclear has priority over gas in France.
Yes, and it shows that the nuclear fleet can always (bar any incident) tackle a rather large scheduled (in hours) modulation, which is a totally different challenge than "realtime" follow-up.
This is, indeed, central here.
It seems to me that, if nuclear can do all necessary follow-up (the fine, low-latency, the part of it which is at best not-well-planned and often absolutely not planned for), it should do so, as it is cheaper and emits less than any fossil-fuel-burning equipment.
I can only see two reasons for this: - the price-calculation method (marginal cost...) used in Europe offers way more benefits by always producing the last kWh thanks to fossil fuel - letting a fleet of nuclear reactors take on all necessary load-follow has some unwanted long-term effect (costs, maintenance, fuel state...)
Are those reasons sound, is there any other one?