I am not sure how it works where you are so bear with me.
I have contacted (in the past) our local energy providers and they always seem to have incentive systems for energy reduction. PG & E has a system called "Savings by Design" where they evaluate your current facility, then recommend changes, then review your changes and give you a nice big fat check (for us in a 107,000 sq. ft facility it was $33,200) The city of Anaheim has "Incentive" which they essentially do the same thing. (for us again in a 215,000 sq ft facility we maxed out the incentive at $45,000)
For interim savings right away, switch to new fluorescent lighting, add occupancy sensors to offices, hallways and restrooms (surprising how much this saves) instruct people to turn off workstations at night, try swamp coolers vs. AC or try BigAss Fans (that is the company name, great website too)
As for tracking changes, ask your energy provider to give you the last full years Kwh used, total cost of Kwh (or have your AP person complete with a lot of research, it is on the bill) then that is your benchmark, then say you spent $790,000 on 1.2 million Kwh total, now you can set a reduction level.
This is actually pretty simple to do if you can afford to give it some time and effort.
Just some thoughts....