I mean Kingda Ka’s launch system was far more powerful than Chiller’s and it had no issues with using too much of the park’s power system.
Kingda Ka used hydraulic accumulators; the hydraulic pumps ran a while, slowly building pressure in the accumulators, and released it in a short period of time.
The issue with magnetic launches is they only consume power during the launch, resulting in very high peak loads. (Yes, there is a constant load from the cooling fans on many launched coasters, but that energy usage is small by comparison and does not contribute energy to the launch of the train.)
The solution to Batman & Robin would have been an energy storage device. The most common for this application would be a flywheel type; essentially a motor attached to the electrical grid drawing a fairly consistent load spinning a heavy flywheel. The flywheel powers a generator that powers the ride. A well known example is for Thunderbird at Holiday World, it uses two 12 ton flywheels to store the approximately 2,500,000 Watts needed to launch a train.
I don't know why more parks with launch coasters don't use energy storage to smooth out their energy use. Grid operators prefer constant loads. I guess for many parks the surcharges for major short spikes in their electrical usage is cheaper than the added cost of operating an energy storage system, plus the extra energy cost from the losses in such systems.
The solar panels they've installed over the years in the back parking lots would supplement the existing power system quite well i would assume
I am not trying to be negative on solar or anything, but the solar panels do not help with night rides. Plus the solar panels are more of a base generating load, and do not meaningfully effect the grid operator's ability to handle short peak electrical loads.