A power failure is not hitting the power switch. After a power failure if correctly configured the PC will restart along with all the correct services.
All my PCs and Cameras are configured on UPS. The disk drive if it is configured with NTFS will not have a problem restarting.
I have been running PC for more than 20 years and the only power problem, that caused equipment failures was a major lighting strike that fried nearly everything. (TVs, alarm system, PCs, stereo, printers, phone system, some light bulbs)