Wind power: for or against the wind?

[Did67]

EdF is still much less affected than the Germans by negative prices; it seemed to me that the market had been disrupted since the erratic production of renewable energies and not because of the nuclear power stations; whatever.

This year, for sure. Half of the reactor fleet is stranded, upgrading work or revisions ...

Nuclear / RE question, it's both: these are productions that we either do not control (some RE - wind, solar and hydraulics "run-of-river" - dams on rivers / Rhine or Rhône); on the contrary, dams modulate very well), or we cannot modulate in the short term (a few hours).

So the "ecologists" will say that at 4 o'clock in the morning, during a windy and rainy period, it is the nuclear power plants that produce too much. The "anti-ecologists" will say that it is the renewable energies. The reality is that the two "uncontrollable" or "non-modulable" energy sources can exceed consumption ...

[sicetaitsimple]

This also affects EdF, unable to brake its nuclear reactors (less this year, half - or not far - is shut down).

Good evening Didier,

it would be nice if on this forum where people are (generally!) relatively serious we manage to get this kind of idea out of our head.

I allow myself to copy some exchanges with Lilian07 a few weeks ago on the wire "electric cars the news wire, on 15/09. It starts with:

lilian07 wrote:
I confirm that a power plant does not start or stop in less than a week or even reduce or increase 25% more power.
...
a power plant does not drive at less than a week, I invite you to check also.

[I] [i]To which I answer:[/ I]

That you believe (and that you confirm it) and that you invite me to check it is one thing, that it is exact is another ...

It just happens that there is an official site, that of RTE, on which you can find in real time (1 / 2h) the production of all groups of more than 100MW unitary power in France, they belong to EDF or to another producer. So, of course, we have to look for a little, because in general, nuclear groups are rather exploited near their nominal load, which is logical because their marginal cost (the variable cost) is the lowest of all non-renewable means of production and therefore they are called first. It is therefore necessary to look for (there are all the histories over several years) towards the beginnings and end of WE, the somewhat hollow days of summer, or the period Noel-New Year's Day.

So my turn to invite you to check, we are never more convinced than when we have even made the effort to search for the raw data rather than to stay on his certainties or hackers peddled on the Internet. [/ i]

By giving examples the very next day:

While we were talking about it yesterday, Unit 5 of the Gravelines power station:

-was at 873MW until 17 p.m.
- decreased towards 520MW between 17 p.m. and 18 p.m., level at which it remained until 21 p.m.
- then rose to 893MW, the level it reached at 22 p.m.

Public data from the RTE site.

And again, the same day:

Unit 2 of the St Alban power station was at 1287MW at 1 a.m., it went between 1h and 2h at 406MW, stayed there until 10h and rose to 1267MW for 11h .... Again public RTE data, available to all those who want to avoid telling bad stories.

The debate ended there ......

[Did67]

Are you sure that ERDF does not take into account only "internal" consumption, that distributed on the French network? A certain number of French nuclear power plants have "contracts" with foreign electricians, or even are co-financed ... We should say "nuclear power plants located in France and operated by EdF".

It is a hypothesis.

But I will try to find out more.

I have always read or heard (which does not mean that it is correct), that except for an emergency shutdown procedure (by graphite pencils which "fall", it seems) nuclear power plants did not "modulate" over very short times ...

[Did67]

If it was possible to adjust so easily, then are the managers stupid enough to sell electricity on the spot rather than shutting down a power plant? You will admit that this raises questions?

[This year, the situation has changed little - or not? - presented for EdF, but in the past, there have been sales at a negative price by EdF]

For your information, here are the participations in Fessenheim (according to Wikipedia):

The power plant was built with the financial participation of three companies: Electricité de France (67,5%), the German company EnBW (17,5%) and a Swiss consortium (NOK, EOS and BKW) (15%). These companies have a right to draw electricity proportional to their financial participation.

I think that the production under this "right of withdrawal" does not enter into the production counted by RTE (it is not a French production).

[sicetaitsimple]

Are you sure that ERDF does not take into account only "internal" consumption, that distributed on the French network? A certain number of French nuclear power plants have "contracts" with foreign electricians, or even are co-financed ... We should say "nuclear power plants located in France and operated by EdF".

It is a hypothesis.

But I will try to find out more.

I have always read or heard (which does not mean that it is correct), that except for an emergency shutdown procedure (by graphite pencils which "fall", it seems) nuclear power plants did not "modulate" over very short times ...

Yes, I am sure, it is the power injected into the network, after where it goes is another subject.

You've always read or heard, but it's just wrong for France, at least since the mid-80s when the power stations were equipped with a so-called "gray" control mode (compared to the initial mode called "black ") allowing this flexibility.

This is not the case in Germany, or in the United States, where in any case nuclear power plants are, except in rare cases, always operated at full load because there are relatively many fewer (I think that German nuclear represented at the peak 25% of total annual production while French nuclear power is around 75%)

[sicetaitsimple]

A complement anyway: I did not say that all nuclear groups (58 in France) could do that in any proportion and at any time. It depends in particular on where they are in their cycle between two reloads. At the end of the cycle, the flexibility decreases.

[sicetaitsimple]

I think that the production under this "right of withdrawal" does not enter into the production counted by RTE (it is not a French production).

Yes Yes. at the time of writing the production of Fesseinheim1 is 858MW on the RTE site.

[sicetaitsimple]

If it was possible to adjust so easily, then are the managers stupid enough to sell electricity on the spot rather than shutting down a power plant? You will admit that this raises questions?

Ah, if it was simple! But in fact it is a little complicated to explain.

But you yourself gave part of the explanation above by writing about negative prices:Let us be precise: price on the "spot" market (sales of surpluses), which represents a tiny share of electricity, negative, in fact at certain times.

[Did67]

Yes Yes. at the time of writing the production of Fesseinheim1 is 858MW on the RTE site.

The "part reserved" for the various foreign companies may well be this evening from 20 pm to midnight or tomorrow morning from 6 am to 8 am, etc ... or the totality of production on certain days, etc ...

IF it is, at time t, there, 100% was reserved for EdF ... But that can switch at such time ???

[Did67]

1) I confirm, after research, that the power of the nuclear reactors can be controlled, in G mode, over very short periods. I found credible documents which relate tests carried out at Tricastin in the 80s, which consisted in reducing the power of a reactor from 900 and a few MW to 400 and a few in 8 minutes, then at the same time going back to the nominal power.

I will never repeat my mistake.

2) It is a French specialty, since it is only in France that the share of nuclear power is so important. Making it pretty essential. Enough for EDF - distribution to impose it on EDF - production.

3) And indeed, in Fessenheim and Bugey, mode G is not applied.