https://x.com/RedElectricaREE/status/1916818043235164267
We are beginning to recover power in the north and south of the peninsula, which is key to gradually addressing the electricity supply. This process involves the gradual energization of the transmission grid as the generating units are connected.
I see load dropping to zero on that graph, or rather, load data disappears an hour ago.
If the grid frequency goes too far out of range then power stations trip automatically, it's not an explicit decision anyone takes and it doesn't balance load, quite the opposite. A station tripping makes the problem worse as the frequency drops even further as the load gets shared between the remaining stations, which is why grids experience cascading failure. The disconnection into islands is a defense mechanism designed to stop equipment being too badly damaged and to isolate the outage.
Last actual load value for Spain at 12:15: https://transparency.entsoe.eu/load-domain/r2/totalLoadR2/sh...
Last actual load value for France at 12:00: https://transparency.entsoe.eu/load-domain/r2/totalLoadR2/sh...
https://transparency.entsoe.eu/generation/r2/actualGeneratio...
Everything dropped to zero except wind and solar, which took huge hits but not to zero. I expect those have been disconnected too, as they cannot transmit to the grid without enough thermal plant capacity being online, but if the measurement at some plants of how much they're generating doesn't take into account whether or not they were disconnected upstream they may still be reporting themselves as generating. You can't easily turn off a solar plant after all, just unplug it.
Either that, or they're measuring generation and load that's not on the grid at all.
Rooftop solar for example just shows as a reduction in demand, not 'generation' per se.