https://en.wikipedia.org/wiki/2025_Iberian_Peninsula_blackou...

The root cause is not known, but Spain was producing excess power (primarily solar) at the time around the disconnect. Some fluctations were seen, then supply started to disconnect from the grid in Spain, leading to sudden loss of 2.2GW of power. In Spain, automatic load shedding then happened to try to recover, but it was too little too late as neighboring countries detached from Spain to protect their own grids.

Nothing about this sounds like an issue with renewables.