So for example if a factory had a lot of motors which present an inductive load they could improve

their power factor by adding capacitance.

This is very common,  even to the point of individual PF correction at the building level.   

Back in the 80s, automated test equipment my group built was failing a lot of produc  on 2nd shift for AC power-related reasons.   So I connected a Dranetz power analyzer to the AC line,  enabled the printer, and left for the night.  

Next morning the entire roll of paper was on the floor.   We found that unknown to anyone, the power company had  installed power factor correction capacitors that were operated by a timer so as to correct for the change in load after first shift operations in nearby factories ended.   After the switch, the analyzer detected an error on every cycle and dutifully printed out an error message.

73, Bob W9RAN