A light control system (120;121) for controlling a lighting system, wherein the light control system (120; 121) is arranged to receive a power reduction parameter ( alpha), the light control system comprising: - a light controller arranged to: - receive a measured light value from a light sensor, - determine a light channel level value depending on the measured light value and a calibrated setpoint value if no power reduction parameter has been received yet, and - determine a light channel level value depending on the measured light value and a scaled calibrated setpoint value when the power reduction parameter has been received, the scaled calibrated setpoint value being equal to the calibrated setpoint value multiplied by the power reduction parameter; and a load controller arranged to receive the light channel level value from the light controller; characterised in that the load controller is further arranged to: - determine an output level signal depending on the light channel level value if no power reduction parameter has been received and - determine a scaled output level signal if the power reduction parameter has been received, the scaled output level signal being equal to the output level signal multiplied by the power reduction parameter, and - send the output level signal or the scaled output level signal to drivers of light sources of the lighting system. - a light controller arranged to: - receive a measured light value from a light sensor, - determine a light channel level value depending on the measured light value and a calibrated setpoint value if no power reduction parameter has been received yet, and - determine a light channel level value depending on the measured light value and a scaled calibrated setpoint value when the power reduction parameter has been received, the scaled calibrated setpoint value being equal to the calibrated setpoint value multiplied by the power reduction parameter; and a load controller arranged to receive the light channel level value from the light controller; characterised in that the load controller is further arranged to: - determine an output level signal depending on the light channel level value if no power reduction parameter has been received and - determine a scaled output level signal if the power reduction parameter has been received, the scaled output level signal being equal to the output level signal multiplied by the power reduction parameter, and - send the output level signal or the scaled output level signal to drivers of light sources of the lighting system. - receive a measured light value from a light sensor, - determine a light channel level value depending on the measured light value and a calibrated setpoint value if no power reduction parameter has been received yet, and - determine a light channel level value depending on the measured light value and a scaled calibrated setpoint value when the power reduction parameter has been received, the scaled calibrated setpoint value being equal to the calibrated setpoint value multiplied by the power reduction parameter; and - determine an output level signal depending on the light channel level value if no power reduction parameter has been received and - determine a scaled output level signal if the power reduction parameter has been received, the scaled output level signal being equal to the output level signal multiplied by the power reduction parameter, and - send the output level signal or the scaled output level signal to drivers of light sources of the lighting system.