Re: Causes of the Gran Apagón (Spain), first oficial report

On 19/06/2025 1:28 am, Martin Brown wrote:

On 18/06/2025 08:39, Liz Tuddenham wrote:

Carlos E.R. <robin_listas@es.invalid> wrote:
>
[...]

...the minister for
ecological transition, Sara Aagesen

[...]

the
"system did not have enough dynamic voltage capacity".

[...]

did not absorb all the voltage
they were supposed to when tension was high," she said,

>
The usual nonsense we have come to expect from 'factual' reports.
Ignorant minister?  Ignorant reporter?  ...or both.

 That is partly due to machine translation out of the Spanish.
 Long and short of it was they didn't have enough dynamic inertia in the system and when it reached high noon something had to give.
 Icarus syndrome - quite literally!

The way I read it is that a relatively large number of relatively low power generators - presumably solar cell farms - were programmed to turn themselves off if the net voltage got higher than some preprogrammed limit.
They all seemed to have turned off at once which is presumably what pulled 3.3GW of generating capacity within thirty seconds.
Icarus died - but the Spanish network survived, as it was intended to do.
It just stopped delivering power for a couple of hours.

In addition the network failed to protect itself from the abnormal state and so went completely dark rather than dropping off the main offenders.

On the contrary, it did protect itself from the abnormal state, but at the considerable cost of a couple of hours of blackout.

I suspect that the French interconnect dropping out was the coup de grace but without the official timeline being published that is a guess.
 A graph of power, frequency and line voltage minute by minute over the relevant few hours would be *very* interesting to examine.
 It is odd that they don't explain why it failed so spectacularly quickly. The final grid collapse took 5s and then it was all over.

The speed is perfectly explicable. If you have lots of identical controllers, all designed to turn themselves off when they see a particular situation, they are all going to turn off at once.
A more intelligent design might have delayed the turn-off by a short, randomly selected delay, so that the excessive voltage might have gone down slowly enough that the impeding turn-off could have been cancelled in the slower reacting controllers before it got put into effect.
Adding grid-battery based fast-reacting controller to the system would presumably have worked rather better.
https://en.wikipedia.org/wiki/Hornsdale_Power_Reserve
does seem to have been used in exactly that way from when it was first installed at the end of 2017. From 2022 it provided about 2000 MW of inertial response to the grid.
--
Bill Sloman, Sydney