Lighting load management system for lighting systems having multiple power circuits

A lighting control system is provided for a space that is equipped with multiple lamps for illuminating the space and multiple power circuits for supplying power to different groups of the lamps. The control system stores information relating to the past illumination of the lamps in each of the different groups. The system detects conditions or events that indicate that increased illumination of the space by the lamps is needed, and produces a control signal in response to the detection of a condition or event that indicates that increased illumination of the space by the lamps is needed. In response to the control signal, the system supplies power to at least one of the power circuits, which is selected on the basis of the stored information, to turn ON the group of lamps receiving electrical power from that power circuit.