[cesarb]

> According to my friend, the freq drop was caused by a sudden large supply surplus over the instantaneous demand.

Wouldn't a supply surplus cause a frequency increase, not a frequency drop?

[cft]

In the case of the rotating generators, yes. In the case of the solar panels, I do not know: I guess it depends on the inverters characterists? Spanish is not my native language, so I may have mixed it up when talking to him.