Power bumps are a major issue and even with redundant power you get them. Even a bump that loses 15-20% of voltage on a single phase for 3-6 cycles (of 60Hz, so like 0.05-0.1s) is a huge impact to fab production tools.

I've seen impacts from cars hitting telephone poles 20 miles away that have been enough to impact the fab, let alone tree branches snapping from snow and ice.

I guess I don't know why this would be an issue - you just pick an area that uses buried power lines, and there are plenty of them. And ignoring that - if you're Intel building a fab, you setup shop near one of the major transmission lines that run well above the treeline. Or build your fab just down the street from the power plant...

St. Cloud, MN. Palo, IA. Brownville, NE. Burlington, KS. - nuclear plants.

I'm sure they all have plenty of cheap land to put fabs up on and if you take one of the norther states you'll cut your cooling bill to less than zero for several months out of the year without any evaporation.

Just having underground lines doesn't stop everything...and no one has underground lines for extremely high voltage.