Smart buildings, homes and industrial facilities will soon use more and more energy harvesting devices that create their own power to run – and wireless ZigBee networks will be a part of that.
The ZigBee Alliance recently made Green Power, which is an optional feature on the ZigBee Pro 2012 specification, available for manufacturers.
Green Power devices like light switches and sensors create their own kinetic power by harvesting the energy from the small amount of heat created when a switch is activated or by other means, such as light or vibration. The devices will only turn “on” for the brief period required to send the signal on the ZigBee network, thereby making the device battery- and wire-free.
“Proxy” devices on the network, such as thermostats and air conditioners, can be used as “routers” to extend the range of the signal and deliver it to a destination device or “sink” like a light fixture.
Because the Green Power devices are wireless, installation can be more convenient and easy. And retrofit options should abound. The devices also use less power, about 200 microjoules, which is about 100 times less than ZigBee in a set-top box.
A ZigBee white paper, New ZigBee PRO Feature: Green Power – Connecting Battery-Free Devices, states:
This innovation facilitates the deployment of wireless sensors in large areas such as tertiary buildings like shopping malls, hospitals and parking garages where it is likely there will be many thousands of devices that would otherwise need to be powered by batteries, which not only substantially reduces building maintenance tasks over time, but is also considerably more environmentally friendly. It allows even the most sensitive industrial areas, where batteries are forbidden for safety concerns, to communicate within a sensor and control network.
The ZigBee Alliance says Green Power devices should be available by mid-year. Proxies and sinks need the Green Power feature, which is an optional feature of ZigBee Pro. Existing ZigBee Pro devices do not use ZigBee 2012, but an existing ZigBee Pro device could be software upgraded then act as a proxy or sink, explains Kevin A. Schader, director of communications for the ZigBee Alliance.
Wireless solutions also help gain sustainability credits from energy efficiency and sustainable buildings programs or groups like the U. S. Green Building Council’s LEED program.