System for controlling operation of a plurality of gaseous discharge lamps for selectively turning on or off one or more of the lamps and producing desired lumen output of the lamps as needed, to provide for conservation of electrical energy. In the system, each of the discharge lamps is connected to a separate variable impedance ballast device, a control circuit for varying the impedance of each ballast device, and a signal processing circuit connected to each control circuit for operating the same, and a signal transmitting device for transmitting information to each of the signal processing circuits, whereby the latter circuits selectively operate the respective control circuits in response to the information received from the signal transmitting device. In a preferred embodiment, the signal transmitting device is a remote transmitter such as a radio frequency signal device for remote control of the lighting system.