Something to think about is that there is a LOT of variables in a chiller plant. To truly optimize the whole plant, you must know how all those variables will affect the system. (Things like Chiller efficiency over it's load range, and how this changes with condenser water temperature. The electrical use for the Cooling Tower fans over their range, etc).
I agree 100%. I think I am going to leave the condenser water alone for now. I will be putting VFD's on the towers and condenser water pumps. The thing that just kills me is they had a plate and frame for free cooling in the winter and they ripped it out! Now they are complaining about having to run the chillers all the time.