Lighting control method for excess electrical power accounting

The invention provides a control system (1000) comprising an electrical power control system (100) for monitoring electrical power consumption by a target system (200), wherein: - the target system (200) comprises (i) one or more dimmable electronic devices (210), wherein each dimmable electronic device (210) comprises a lighting device (220), wherein the one or more dimmable electronic devices (210) are operable at a plurality of different dimming conditions thereby defining a dimming range of the one or more dimmable electronic devices (210) with a predetermined relation between the plurality of different dimming conditions and an electrical power consumption by the one or more dimmable electronic devices (210), (ii) a target control system (230) configured to control the dimming conditions of the one or more dimmable electronic devices (210), and (iii) a source of electrical power (240) configured to provide electrical power to the one or more dimmable electronic devices (210); - the electrical power control system (100) is configured to execute an electrical power control operation comprising (i) bringing the one or more dimmable electronic devices (210) consecutively at N different dimming conditions, wherein N is at least 2, (ii) sensing the respective electrical power consumptions during the N different dimming conditions, and (iii) determining in a determination stage whether or not a further electronic device (10) having deviating dimming behavior or having no dimming functionality is functionally coupled to the source of electrical power (240) based on a comparison of the sensed electrical power consumptions and the predetermined relation between the plurality of different dimming conditions and the electrical power consumption.