But according to production data it has never dropped to zero? Why it would be a black start? It dropped from about 32GW to about 8GW source: https://transparency.entsoe.eu/generation/r2/actualGeneratio... though admittedly https://en.wikipedia.org/wiki/Black_start mentions that partial shutdown may be also requiring a black start?
Dropping from 32 to 8 GW usually means that an interconnected grid has fragmented into islands. If an island has a blackout, you need to black start it and resynchronise it with other islands.
It looks to me like the author of this article has fundamentally misunderstood what a black start is. The fact that some power generation remained both on the peninsula, but also on imported power being available means that to my understanding this cannot be classified as a "black start". A lot of overtime, a lot of careful coordination yes, a black start, no