In your attempt to be overly dramatic you have designed an example that could never occur. There is NO WAY a 50 stall, 250 kW Supercharging location could have a peak draw of 12,500 kW. First of all, 50 stalls is enough to ensure there is reasonably random distribution of cars in various states of charge, ie, all 50 cars could not park and plug in simultaneously and all cars would not be at such a low state of charge that they would all draw the maximum of 250 kW, not even initially. Version three superchargers only dole out 250 kW for a small fraction of the total charging time and quickly ramp to below 150 kW by 50% state of charge and continue to rapidly taper to below 50 kW by 80% state of charge. And since the charging power is continuously tapering, the bulk of the charging time will be at much lower numbers than 250 kW. And then you have to average in all the cars that are not charging at all, either because they just plugged in and have not begun the quick ramp to the maximum charge rate the battery will accept (which will be below 250 kW in many cases, either due to not being 250 kW compatible (Standard Range models or older models) or because they are already over 50% state of charge) or because they have just unplugged but not left the stall or another car has not pulled in or plugged in yet. I think at PEAK draw, a 50 stall, 250 kW station could, at most, draw up to around 30% of your estimate of 12,500 kW demand charge. This would be when there was a line to plug in.