New Cree LED Light Fixtures Are PoE, or Powered Over the Ethernet

This story is part of Treehugger's news archive. Learn more about our news archiving process or read our latest news.
A cubicle farm with LED lighting


This isn’t the kind of office interior we usually show on TreeHugger, It’s kind of ordinary looking. But the new offices of IT services company mindSHIFT are actually not ordinary at all; the light fixtures in this data center are Cree SmartCast LED luminaires and they are not connected to the usual 120 volt wiring. In fact, they are plugged into the bog standard CAT 5 ethernet cable that you plug into your computer, which is connected to a CISCO Power over Ethernet or PoE network. These are all connected to Smartcast manager tools that can set them up in seconds.

And this changes everything when it comes to office and probably in the not too distant future, home wiring and design.

Traditional Office Wiring

In a traditional office there are layers and layers of different wiring hierarchies; you will have your power wiring, in either 120 or 227 or even 600 volts. Then there might be HVAC control wiring to valves and control boxes and thermostats. Then telephone and finally computer wiring. In the control room the lighting controls will be separate from the HVAC and the power will be in another electrical closet altogether. Fancy systems might have one or two occupancy detectors in the room.

PoE changes all that. Everything, from the light fixtures to the HVAC to the window blinds are connected via CAT5. Every single light fixture becomes part of the Internet of Things.

How PoE Lighting Enhances the Modern Office

Smartcast diagram

Cree writes that “A common misconception is that the IoT enables smart lighting, but, unlike many other ‘things’ of the IoT, it’s the converse - LED lighting enables the IoT.” This is absolutely true; those CAT 5 cables can only carry 25 watts of power. A fluorescent fixture only turned on or off, most couldn’t even dim. The SmartCast luminaires and can be adjusted for color temperature and light levels and can run under PoE limits.

Each fixture has an occupancy sensor right on it and can talk to every other internet connected device, which lets it do some very smart things. In an interview, Gary Trott, Vice President, Marketing, Intelligent Lighting, gave an example;

Suppose a group meets in a conference room. The occupancy detector can turn on the lights and adjust them to the desired level (taking into account how much daylight is coming through the windows) but it can get warm in a crowded room quickly. Usually it would take time for a CO2 detector or a thermostat to notice, but the lights can now tell the mechanical system to crank up the AC in anticipation.

All kinds of things begin to happen when your lights and your mechanical system can talk to each other and to your computer. It can save a lot of energy, and provide a lot of control.

SmartCast Manager extends Cree’s SmartCast PoE into IoT applications by harvesting data that helps building owner operators manage energy usage as well as the safety and vitality of building occupants. The data harvested from the lighting system can be used to track crowd locations within a building in case of emergency, manage the usage of the HVAC system based on building capacity or offer personal control of lights to improve employee productivity.

It’s not only good for productivity but also for health. The WELL building standard, for example, notes that we are sensitive to changes in lighting:

Humans are continuously sensitive to light, and under normal circumstances, light exposure in the late night/early morning will shift our rhythms forward (phase advance), whereas exposure in the late afternoon/early night will shift our rhythms back (phase delay). To maintain optimal, properly synchronized circadian rhythms, the body requires periods of both brightness and darkness.

This is where LEDs come into their own, because they are the only artificial light source that can do this easily.

The Accessibility of PoE Lighting

Two offices, one with a red wall and one with a blue wall

Gary Trott thought it important to point out that mindSHIFT isn't some fancy expensive New York office with New York values, as Ted Cruz might call it. It's a basic, working office like you will find just about everywhere. It also seems that the people who designed the mindSHIFT offices wanted to give the lighting system a workout; perhaps each office occupant can turn down the red or the blue as required to survive in that space.

Further capabilities include advanced energy saving methodologies. Building operators can employ aggressive control settings, for occupancy detection, daylight harvesting and other energy-paring strategies, like task tuning to adjust lights in specific areas where lower light levels are desired. For example, lights can be set to lower levels in conference rooms compared to work spaces where more light is needed in order to see detail.

The energy savings are nice, but what really impresses is the control, the flexibility, and the elimination of layers of wiring installed by different trades, the elimination of high voltage so that anyone can move or replace a fixture as needed. In the future, I suspect our homes also might be wired this way, eliminating most of the problems people are having with the so called smart home technology we have now. It just all makes so much sense.