Would be a pretty small gen-set. The problem with this hit piece is; no one seems to understand exactly how much juice it takes to run a supercharger. As E718 pointed out in one of my earlier posts, the 12 stall facility at Billings has enough electric service to run a typical ethanol plant. That's just for 12 stalls. Now try powering 8 times as many and in order to do all of them, you would need two of the gen sets I posted. Could you put a 100 KVA gen-set in the building you outlined, maybe, but for what purpose? That's only good for less than half of one 250 KW stalls that are being set up. When the battery in my car is around 30% and the temps are proper, it will take 600+ Amps @ 400V for a few minutes. A little plant in that building is a drop in the bucket for what is needed for one car, let alone 96! Hardly worth the expense and effort.
As of yet, no one has explained why the "investigative reporter" neglected to get pics of the generator he referenced. Your picture looks to be in a publicly accessible area so there is really no reason the reporter couldn't have snapped pics of the cooling vents & exhaust stacks if there really was a gen-set in the building.