Can TRIAC dimmers cause lagging power factor?

The building that I manage has a film production sound stage with an old lighting system. It is not unusual for the stage to use 30 kW of lighting. In the past we have seen lagging power factor corrections on our utility bill that I have always attributed to our air conditioning load, but we just recently got hit with one when I know that we weren't using enough ac to cause it. My question is could the dimmers from the lighting system for the stage be contributing to the lagging power factor?