The (Power-over-Ethernet) power distribution system comprises a lighting unit (40-80) for producing light. The power distribution system further comprises at least two (Power-over-Ethernet) switch units (20, 30) each having a plurality of ports (25, 35). The at least one lighting unit (40-80) is coupled to at least a first port of the first switch unit and a second port of the second switch unit. The switch units further each comprise a power supply unit (21, 31) for supplying power for the respective plurality of ports (25) and the at least one lighting unit (40-80). The power distribution system furthermore comprises at least one load management unit (100) for controlling the power supplied by the respective power supplies of the switch units to the at least one lighting unit (40-80) such that the power efficiency of the distribution system is optimized.