Fabs have all sorts of power systems because even the slightest blip or glitch in power could mean millions in losses I know a decade or two ago IBM was using

Fabs have all sorts of power systems because even the slightest blip or glitch in power could mean millions in losses I know a decade or two ago IBM was using superconducting magnets for power smoothing to handle sub-millisecond events. Then you have battery and flywheel systems for bigger drops that are designed to carry load until generators can start and accept load (usually a very short period of time if the generator's oil and coolant are on heaters.)