Redwood Systems, the startup with the future-forward idea of LED lighting that’s both powered and networked via Ethernet cables, has just landed a showcase client — Facebook. The social networking giant has chosen the LED-over-Ethernet networking startup to install lighting and sensor systems in its new super-efficient data center in Prineville, Ore. While retrofitting a building to use only LEDs that can run on the low power available over Ethernet can be a daunting affair, building a new data center around the concept — and then allowing all kinds of sensors and controls to use the same Ethernet infrastructure — makes a lot of sense. Redwood Systems has been getting a lot of play recently — Johnson Controls just installed its system in its Milwaukee, Wisc. headquarters, and may be looking to use the startup’s system in projects for other clients, including the idea of using it for networking retail store checkout counters. In a sense, Redwood Systems is in a different category than the rest of the lighting controls vendors out there, which tend to focus on traditional control panel and wiring solutions or newer, cheaper and more retrofit-minded wireless solutions. Until LEDs catch on en masse, it will be hard to imagine Redwood’s concept becoming mainstream — but for efficiency minded clients like Facebook and specialty environments like data centers, it may well be a perfect match.