Ethernet-Powered LED Lighting
Facebook mentions in passing that its highly efficient Prineville data center uses "Ethernet-powered LED lighting [to] reduce the total energy required to run the facility." Additional information about what exactly Facebook has done is hard to fine. What is Ethernet-powered LED lighting?
Converter Technology (UK) supplies the the answer. "Power over Ethernet according to IEEE802.3af allows power to be delivered over standard CAT5 cable alongside the data services. This allows small, remote devices to be powered without needing a mains adapter and the associated wiring costs this involves. Up to 13.5W can be drawn from the CAT5 cable which gives a useful power output of around 10W once conversion efficiency has been considered. " The company publishers a reference spec for driving LEDs this way.
Redwood Systems (US) uses a similar capability to integrate LED power and building energy management SCADA on the same cable.
Apple's new data center features "High-efficiency LED lighting combined with motion sensors" but it is not clear if the LED power and senor data is combined onto Ethernet cable.