Power Factor confustion

Hi,


I have a new metering system installed  which uses CTs at the main distribution. One on the main supply 1,600a, then meters on the first level of breakers, between 125a and 630a. 


Because of how we operate, sometimes the load is a couple of amps, and other times its banging it out at close to the capacity of the breaker. 


The load is machine tools, mix of inverters and direct, the lighting and general industrial uses



one area seems to have a really bad power factor, around 0.5, but depending on the loading, it can be as good as 0.8 


another area is very lightly loaded, and that has a power factor that swings from -0.8 to 0.9, that's got office equipment on it, heat pump some lights


I have 600kVAR or power factor correction at the main breaker, no meters on that.



The meters look like they are all connected fine, and the other readings are sensible and accurate, kW all positive readings so I don't think there is an error with the installtion.



I guess the question really is, should I be getting hung up on the power factor, or focus on the kWh to target energy savings? Has anyone had experience of it varying like this?