Much smaller-scale, but I worked at a company with a mini-mainframe-type computer (VAX-11/780, iirc) that had a 'motor-generator' to run it (really a motor-flywheel-generator).

The computer, storage, etc. ran off the generator, which first eliminated any risk of power spikes and surges (as the flywheel is a very effective low-pass filter), and the circuits controlling motor speed also ensured the AC frequency was better than the power company supply. This was located in a rural area, so the long power lines with few sinks (customers pulling power) made lightening spike risk spread further, and the rural voltage and frequency fluctuated a lot. Seemed like a really cool system that worked flawlessly in the years I was there.