Metrics that you actively watch generally lead to much higher improvements.
Given the amount that most factories pay on electricity each month, this means that closely watching your usage should be a high priority.
Advances in technology means that it is now cost effective to add multiple current meters onto your power lines, to constantly track electric usage in real time.
This can either work at a broad level per zone, or even connected to individual machines. Clip-over sensors allow easy installation without any disconnection or down time.
You then have the power to set comprehensive monitoring, reporting and alarms.