Reactive power of current leading loads
Good question.

Wikipedia's article on Power Factor states:


  Lagging and Leading Power Factors:
  
  In addition, there is also a difference between a lagging and leading
  power factor. A lagging power factor signifies that the load is
  inductive, as the load will “consume” reactive power, and therefore
  the reactive component Q is positive as reactive power travels through
  the circuit and is “consumed” by the inductive load. A leading power
  factor signifies that the load is capacitive, as the load “supplies”
  reactive power, and therefore the reactive component Q is negative as
  reactive power is being supplied to the circuit.


I can't quite make sense of the logic here. I suspect that it might be just convention in that most industrial load is inductive and that power-factor measurements were always 0 to 1. For the occasions when it goes capacitive the sign is changed.

I would be happy to be educated further on this.