Probably didn't help that before the outage hit, Spain was running its grid with very little dispatchable spinning generation, and therefore not much inertia.

Solar PV/thermal + wind: ~78%

Nuclear: 11.5%

Co-generation: 5%

Gas-fired: ~3% (less than 1GW)

I would _love_ to understand more about how this atmospheric state impacted the vibration of power lines. Sounds exotic.